DIY - Bypassing Tire Pressure Warning System (TPWS / TPMS)

[CTScott]

Note: Please jump to page 3, post #45. The first pass of a solution on pages 1-3 ended up not working.

For the simple method, please jump to post 115. This method does not require resistors.

http://www.yarisworld.com/forums/showpost.php?p=348077&postcount=115


Following is a DIY to disable the system, without causing the TPWS light or MIL (malfunction indicator light {or check engine light, as some like to call it}) to light.

A while back there was a thread about the issues with either using rims which are not compatible with the tire pressure sensors or running two sets of rims. The Yaris TPWS can only be programmed to respond to one set of four sensors. To switch to a second set, you would have to bring your car to the dealer to have the TPWS reprogrammed for the second set (This is typically about a $90 charge).

I did a bit of reverse engineering on the TPWS and believed that I found a soultion. Linny recently tried this solution and verified that after more than 100 miles of driving there were no issues.


Procedure :
(WARNING: Modifying anything on the Yaris is done at your own risk!!!)


The TPMS ECU is located behind the lower passenger glove box:

http://i372.photobucket.com/albums/oo163/ctscott329/TPWSLocation.jpg


The TPWS system will only report an issue with not hearing from the sensors if for 15 minutes it doesn't hear from a sensor while the vehicle speed is 5 MPH or greater and the Engine speed is 1000 RPM or more.

To keep the system from reporting an error, do the following:

1. Start without an error: If you start with the system in the error free state (by starting the vehicle and having the 4 tires with the sensors next to the vehicle (or mounted on it) and ensure that the TPWS light is not lit or flashing.

2. Shut the engine off.

3. Pull out the lower passenger glove box and locate the TPWS ECU (to the right, just above the fan assembly):

http://i372.photobucket.com/albums/oo163/ctscott329/TPWSPicture.jpg

3. Clip and cap both ends of the VSS and ESS wires to the TPWS ECU. Leave a couple of inches on the connector side so that you can resplice if you wish to re-enable the system. The connector is shown below. The VSS wire is the Violet one and the ESS wire is the red one, two pins after the violet one. Also, if you wish to switch between a set of rims with sensors and a set without, you can add a DPST (dual pole, single throw) switch to disconnect / reconnect both wires as desired to disable/enable the TPWS.

http://i372.photobucket.com/albums/oo163/ctscott329/TPWSConnectorPicture.jpg

For adding the switch the following is a good choice:

http://media.digikey.com/photos/Cherry%20Switch%20Photos/RRA32H3FBBNN.jpg

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CH867-ND

To wire the switch, connect the cut wires to the sets of terminals on either side of the switch as follows:

Red - - Red
Vio - - Vio


Someone posted a DIY of disabling the feed to the light (the brown wire on the connector above, if you were wondering). The problem with just clipping this wire is that the DTCs will still be logged and may result in your Malfunction Indicator Light coming on.

[Tamago]

very nice :)

[kou]

i will be doing this in the spring.thank you.:clap:

[TheSilkySmooth]

Super DIY write up. Thank you CTS for the effort! I am planning to put vinter tyres on My Daughter's Yaris and was concerned about setting a code as she is due for Emissions and saftey inspection this november. The SW seem like a good idea. CTS You dont have to shunt any of the cut wires to keep an open antenna out of the ECU?

Does anyone know if the 14" steel rims sold through Tire rack or Discount Tire Direct will clear the calipers? Her car has optional 15 inch rims. I wish to put a 165-70 snows on the front to get better force/unit area (µN/cm2) at the contact patch.

Thank you for helping,

- Papa

[Tamago]

Super DIY write up. Thank you CTS for the effort! I am planning to put vinter tyres on My Daughter's Yaris and was concerned about setting a code as she is due for Emissions and saftey inspection this november. The SW seem like a good idea. CTS You dont have to shunt any of the cut wires to keep an open antenna out of the ECU?

Does anyone know if the 14" steel rims sold through Tire rack or Discount Tire Direct will clear the calipers? Her car has optional 15 inch rims. I wish to put a 165-70 snows on the front to get better force/unit area (µN/cm2) at the contact patch.

Thank you for helping,

- Papa

14's should clear fine, stock brakes aren't huge.. +39 offset should work as well

[CTScott]

Super DIY write up. Thank you CTS for the effort! I am planning to put vinter tyres on My Daughter's Yaris and was concerned about setting a code as she is due for Emissions and saftey inspection this november. The SW seem like a good idea. CTS You dont have to shunt any of the cut wires to keep an open antenna out of the ECU?

Does anyone know if the 14" steel rims sold through Tire rack or Discount Tire Direct will clear the calipers? Her car has optional 15 inch rims. I wish to put a 165-70 snows on the front to get better force/unit area (µN/cm2) at the contact patch.

Thank you for helping,

- Papa


No shunting is required. The two wires we are disconnecting are both 12 V analog signals which the ECU is pulling through A to D converters. We shouldn't be able to pick up enough noise to cause a false signal detection.

[Tamago]

No shunting is required. The two wires we are disconnecting are both 12 V analog signals which the ECU is pulling through A to D converters. We shouldn't be able to pick up enough noise to cause a false signal detection.

i thought speed and tach signals were both pulse signals.... ?

[CTScott]

i thought speed and tach signals were both pulse signals.... ?

They are frequency modulated pulses. The TPMS microcontroller pulls them in through an analog input.

[Tamago]

They are frequency modulated pulses. The TPMS microcontroller pulls them in through an analog input.

ah cool so where they enter the ENGINE ecu they're pulse signals, then they go out to the cluster as pulses (correct me if i'm wrong, i recollect setting up a Defi VSD heads up display, and grabbed pulse signals for tach/speed) and the ECU also sends analog outputs to the TPMS?

do you have a wiring diagram of the ECU?

[CTScott]

ah cool so where they enter the ENGINE ecu they're pulse signals, then they go out to the cluster as pulses (correct me if i'm wrong, i recollect setting up a Defi VSD heads up display, and grabbed pulse signals for tach/speed) and the ECU also sends analog outputs to the TPMS?

do you have a wiring diagram of the ECU?

The ECU sends the same pulsed signal to the cluster and the TPWS. The Combo Meter has a microcontroller, which reads the tach and VSS inputs directly, as well as a CAN bus interface to get the odo data and MIL input from the ECU. All of the "data" signals are 12 V, so the microcontrollers have to level shift them to use them (via optoisolator, A-D, etc.).

The Defi's micro would have to do the same thing. By the way, was the Defi VSD worth the money?

For the wiring diagrams, I just have the 09 service manual.

[Tamago]

The ECU sends the same pulsed signal to the cluster and the TPWS. The Combo Meter has a microcontroller, which reads the tach and VSS inputs directly, as well as a CAN bus interface to get the odo data and MIL input from the ECU. All of the "data" signals are 12 V, so the microcontrollers have to level shift them to use them (via optoisolator, A-D, etc.).

The Defi's micro would have to do the same thing. By the way, was the Defi VSD worth the money?

For the wiring diagrams, I just have the 09 service manual.

i've installed 3 sets.. one on my xA the base VSD.. it was essential to life for me until it was vandalized :( it would record max speed/RPM which worked well for primitive datalogging at autocross..

the second one was the VSD that would hook up to the LINK system.. this one went in the yaris. speed/tach on the windshield is awesome..

i now have a VSD-X for my xA.. it has its own screen. i had it installed for a bit then removed it. it's a nice piece but a little OTT for this build. i believe DEFI has discontinued all their HUD's..

[Chupacabra]

Scott,
Insanely awesome thread! Thank you!!!....

[blacksandiegovitz]

Man soooo killer. Installed trd/racing hart 18" and didn't have the sensors installed on them , Im so over the "warning" light on the dash . I'll be doing this this weekend .

[linny]

The hardest part about this procedure was pulling the glove box out! Thanks CTSCOTT! I tried to get the service guy at our dealer to tell me how to disable the system and he wouldn't budge. He would just offer that what most people do is simply 'deal' with the light since most do not have the want or resources to drop $90 each time they want to switch rims/tires.

[mikenacarato]

very nice! i was just about to ask if there was a way to bypass it and then i saw this.

[Ratboy]

okay...you guys lost me. Do you need to cut the wires or can you just leave it unplugged? Or are you just cutting the two wires?

[linny]

I cut the two wires as specified in the pictures provided by CTSCOTT. After cutting the wires I wrapped each of the ends from the two wires in electrical tape. I then plugged the connector back into the ECU unit and that is it!!

[Yarice]

Does this project also work for an 2008 3dr LB?

[CTScott]

Does this project also work for an 2008 3dr LB?

Yes. TPWS is identical on 2008 and 2009 3 and 5 door LBs and Sedans as well.

[CTScott]

okay...you guys lost me. Do you need to cut the wires or can you just leave it unplugged? Or are you just cutting the two wires?

You do need to keep the connector plugged in (with those two wires cut) to sucessfully do the mod. If you just unplug the connector, the TPWS light will immediately come on and will stay on until it is plugged back in.

Cutting those two wires fools the Tire Pressure Warning System into thinking that the car is not moving and the engine is not running. The TPWS will not report an error if it doesn't hear from the tire sensors as long as the car is not rolling and the engine is not running.

[TheSilkySmooth]

My daughters car seem to idle low and loose pick-up and have flat spot on throttle tip-in when the heater or headlights or radio are on. Is there a power buss or GND I can check that may be intermittent? Also does the Cluster dimmer use PWM PSU for voltage control for brightnes or is it just a ballast pot (I'm thinking NO here in digital age). Reason I ask is, I was driving here car and someone knocked-off the display brightness, I turned the knob to mid range and I lost power and engine got buzzy on the highway. May just co-incidence. I wondering if this car is hyper-sensitive to noise on the power buss - also given SS regulated DC which is pretty noisy too - enough to false certain sensor input? I suppose what I am getting at when you drive car initial reaction is - this car has electrical problem - it s over sensitive to control settings. Everything off it runs OK again after ~ 1 cold and a couple HOT key-on/key-offs. This is bad enough I consider SELLING it since it appears on the unrepairable given the tech training level we have around here (NH). Possibly anything I should look for on the hand held - like fuel trim or low E at ECU buss? I want to look for a pattern of corrupted look up tables (and I dont have OBDii scanner, but plan to purchace one.)

Thank you

[Yarice]

Nice, thanx for that info, cant wait to try it out.

[Tamago]

My daughters car seem to idle low and loose pick-up and have flat spot on throttle tip-in when the heater or headlights or radio are on. Is there a power buss or GND I can check that may be intermittent? Also does the Cluster dimmer use PWM PSU for voltage control for brightnes or is it just a ballast pot (I'm thinking NO here in digital age). Reason I ask is, I was driving here car and someone knocked-off the display brightness, I turned the knob to mid range and I lost power and engine got buzzy on the highway. May just co-incidence. I wondering if this car is hyper-sensitive to noise on the power buss - also given SS regulated DC which is pretty noisy too - enough to false certain sensor input? I suppose what I am getting at when you drive car initial reaction is - this car has electrical problem - it s over sensitive to control settings. Everything off it runs OK again after ~ 1 cold and a couple HOT key-on/key-offs. This is bad enough I consider SELLING it since it appears on the unrepairable given the tech training level we have around here (NH). Possibly anything I should look for on the hand held - like fuel trim or low E at ECU buss? I want to look for a pattern of corrupted look up tables (and I dont have OBDii scanner, but plan to purchace one.)

Thank you

i think this question deserves its own thread ;)

[Yarice]

Just finished my lil project, no more stupid TPMS light, AHHH YEAHHH!!

[ivanmadeline]

I tried this today on my car but the light came back on did any one have this problem after cutting the cables. Thanks

[CTScott]

I tried this today on my car but the light came back on did any one have this problem after cutting the cables. Thanks

Was the light on before you clipped the wires? The system needs to start in a non-error state (i.e. light not on).

[ivanmadeline]

The light was off. I took the car to the dealer for the first oil change and i change the rimms before i went i told the to chech the light that it was on an they reset it for me. I got a question I can remeber is it suppose to come on when you first start the car and it goes off again. Tha's what it was doing after they reset on the dealer but the light was off when i cut the wires. thanks for your response.

[Yarice]

Mines didnt work either, my light came on after 15 miles or 15 minutes of driving. Started the car with no TMPS indicator light, shut the car off and cut the 2 wires and cap them and re-plugged the harness. Tired doing this twice, the second time I made sure the TMPS indicator lights wernt present and I disconnect and reconnected the lights came on after 15 miles.

[Yarice]

this is what I did

[CTScott]

The system has to be in comm with the sensors when you do the mod (step 1). You need to have the sensors on your old rims (with tires) and have them next to the car before you shut it off and cut the wires.

[Yarice]

Thats what I did, all 4 tires w/TMPS sensor were next to my new rims, then I started the car, no TMPS lights, then I shut off the car, then I cut and cap the wires, it was groovy for about 15 minutes.

[ivanmadeline]

I had the factory rims with the sensors when I did all the steps. After I finished and saw the that the light was off I change the rims.

[Yarice]

So your telling me I have to mount the stock wheels w/TMPS on first and then do all the the steps and them mount my new rims?

[ivanmadeline]

So your telling me I have to mount the stock wheels w/TMPS on first and then do all the the steps and them mount my new rims?

No I was letting CTScott know that i had the sensors on when I did all the steps and that It didn't work.

[CTScott]

OK. Now we have to figure out what is different between the two of yours', and Linny's...

[ivanmadeline]

Mine is and 08 Sedan stick just in case.

[Yarice]

Mines an 2008 3dr LB

[Yarice]

Ive done this 3 times and im not gonna move the car till tomorrow and let the car sit overnight if thats gonna make a difference, if not im gonna put everything back the way it was.

[CTScott]

OK. Linny just PM'd me. His had been working fine until he headed out of town for Thanksgiving. All of his trips prior had been short (<6 miles). About 15 minutes into his trip the light came on.

So, it looks like this solution does not work - It looks like the third component is time.

[CTScott]

OK. Linny just PM'd me. His had been working fine until he headed out of town for Thanksgiving. All of his trips prior had been short (<6 miles). About 15 minutes into his trip the light came on.

So, it looks like this solution does not work - It looks like the third component is time.

Looked into it a bit more. The TPMS starts a timer once it receives power. After ~15 minutes of power and no comm from the sensors it turns the light on.

I am now experimenting with just using the brown wire, which is the output to the combination meter. To turn the light off, the TPWS module supplies ~4.0V to the brown wire. At 2.4V or less the light will come on.

I disconnected the TPWS and applied ~4.0 V to the brown wire (via a resistor voltage divider from the 12V supply on the connector). The light does not light. I will drive around for a week or so to make sure that eliminating the module doesn't cause a DTC to be thrown.

[ivanmadeline]

Thanks for the help.

[CTScott]

Looked into it a bit more. The TPMS starts a timer once it receives power. After ~15 minutes of power and no comm from the sensors it turns the light on.

I am now experimenting with just using the brown wire, which is the output to the combination meter. To turn the light off, the TPWS module supplies ~4.0V to the brown wire. At 2.4V or less the light will come on.

I disconnected the TPWS and applied ~4.0 V to the brown wire (via a resistor voltage divider from the 12V supply on the connector). The light does not light. I will drive around for a week or so to make sure that eliminating the module doesn't cause a DTC to be thrown.


OK. I've been driving around today with the TPWS disconnected as above, and no TPWS light. We are going out to dinner tonight, and where we are going is about 35 minutes away, so that will be a good test. If the light remains off and I still don't have any DTCs logged, when I get home tonight I'll post the updated method.

[Yarice]

Sweet, thanxs for the update, were all waiting to see how it goes.

[blacksandiegovitz]

damn , so this doesn't work ???? good thing I didnt go cutting wires . Im just gonna have my sensors installed on my racingharts when I get them powder coated .

[CTScott]

OK. I've been driving around today with the TPWS disconnected as above, and no TPWS light. We are going out to dinner tonight, and where we are going is about 35 minutes away, so that will be a good test. If the light remains off and I still don't have any DTCs logged, when I get home tonight I'll post the updated method.

OK. The new solution looks good. After a bunch of short trips and a 30 minute each way dinner run, no TPWS light and no logged DTCs. The new solution goes as follows (and does not require the system to have been light-free prior):

This procedure requires some minor soldering and can be done with or without a switch to re-enable the TPWS.

1. Make a simple voltage divider to provide ~4 Volts to the TPWS light input to the Combination meter.

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/Parts.jpg

Parts Required:
3 150 ohm resistors (radio shack part # 271-1109 for a 5 pack)
22 AWG Wire (Red, Black, green (also yellow and blue if using switch)
Switch(optional), SPDT toggle or push on/off (Radio Shack part # 275-1555)
Heat shrink tubing or electrical tape
18-22 AWG (red) tap-splice connectors (3 for no switch, 4 for switch)

a. Solder three 150 ohm resistors end to end.
b. Solder a 6" piece of black wire to one end and a 6" piece of red wire to the opposite end of the string of resistors.
c. Solder a 6" piece of green wire between the first and second resistor from the black wire end.

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/VoltageDivider.jpg

d. Cover the resistors with heat shrink tubing or electrical tape.

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/VoltageDividerWrapped.jpg

e. Skip to step 2 if not adding a switch.
f. Solder a 6" piece yellow wire to the center terminal of the switch
g. Solder a 6" piece of blue wire to one of the end terminals of the switch.
h. Solder the free end of the green wire to the other end terminal of the switch.

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/SwitchWired.jpg

i. Cover the exposed switch terminals with heat shrink tubing or electrical tape.

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/Done.jpg


2. With the car powered off, unplug the TPWS module connector
3. Clip the brown wire (leave a couple of inches so you can reconnect later if so desired)

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSConn1.jpg

4. Using a tap splice, connect the red wire to the red wire on pin 7 (This red is next to an empty spot at position 8 {RED, empty, white, white, grey, black})
5. Using a tap splice, connect the black wire to white wire on pin 9 (Next to the empty spot after the red wire {red, empty, WHITE, white, grey, black})

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSConn2.jpg

6. If not using a switch, connect the green wire to the brown wire which goes to the combination meter (not the connector end of the cut wire).
7. If using the switch, connect the blue wire to the brown wire which goes to the combination meter (not the connector end of the cut wire).
8. If using the switch, connect the yellow wire to the other end of the brown wire, which is attached to the connector.
9. If not using the switch, leave the TPWS connector off. If using the switch, plug the connector into the TPWS.
10. Turn on the ignition. If not using the switch, the TPWS light should be off.
11. If using the switch and the TPWS light is on, press the switch and the light should turn off.

[eTiMaGo]

interesting... One thing I am curious about, what kind of signal do the sensors give out? Is it just a binary "too low/good" signal or an actual value representing the pressure for each wheel? If it's the second case, it would be quite cool to hack those signals into an actual per-wheel pressure display!

[CTScott]

interesting... One thing I am curious about, what kind of signal do the sensors give out? Is it just a binary "too low/good" signal or an actual value representing the pressure for each wheel? If it's the second case, it would be quite cool to hack those signals into an actual per-wheel pressure display!

The sensors transmit a packet with their ID, pressure, and temperature. Hacking the protocol would be an interesting project...

[linny]

Thank you for putting so much effort into this modification CTSCOTT. I will make a trip to Radio Shack when they open this morning!:smile:

[CTScott]

Thank you for putting so much effort into this modification CTSCOTT. I will make a trip to Radio Shack when they open this morning!:smile:

I realize that this solution is a bit more work than the original cut two wires one, so if anyone needs to do this and doesn't have the equipment, etc. to solder it up, I can make it up and ship it as a nice little kit.

[ivanmadeline]

Thanks for all the work CTSCOTT I just got back from Radio Shack with all the items. I hope that this time it all works.

[Chupacabra]

awesome write-up Scott!

[blacksandiegovitz]

Yes , you got it too work , thats great ! Thanks for doing the research/testing for this fix . I'll be doing this within the next couple days , im so over that damn light in the dash.

[CTScott]

Please look at the directons on page 3. Based on feedback of mixed results, I changed the resistor value as the original value was causing a valtage drop that put it on the edge, where it would work on some cars and not on others.

[ivanmadeline]

Please look at the directons on page 3. Based on feedback of mixed results, I changed the resistor value as the original value was causing a valtage drop that put it on the edge, where it would work on some cars and not on others.

I tried doin it on Sunday but the problem I had was that when I hit the button the light would start flashing the it would come on then I hit the button again and the same thing it would just flash for a few minutes and then stay on again.
I dont know if this makes a difference but i Dont have a brown cable on mine I have a white with a black stripe were that brown one is on your write up. Any suggetions. thanks for all your help.:thumbsup:

[CTScott]

I tried doin it on Sunday but the problem I had was that when I hit the button the light would start flashing the it would come on then I hit the button again and the same thing it would just flash for a few minutes and then stay on again.
I dont know if this makes a difference but i Dont have a brown cable on mine I have a white with a black stripe were that brown one is on your write up. Any suggetions. thanks for all your help.:thumbsup:

Can you take a picture of your connector? The part number is the same for 08 and 09 sedans and LBs, so even though the wire colors are different, their functions are identical.

If your connections are in the correct place, try measuring the voltage on the "brown" wire with the switch in both modes. With the TPWS connected (and the sensors not present) you will read ~1 VDC. Withe the TPWS bypassed you should read ~4 VDC. If the voltage is less than 3 VDC, the light will remain on.

If you do measure less than 3 VDC, you will need to change the resistiors to 150 ohm, 1/2 watt ones.

[ivanmadeline]

Can you take a picture of your connector? The part number is the same for 08 and 09 sedans and LBs, so even though the wire colors are different, their functions are identical.

If your connections are in the correct place, try measuring the voltage on the "brown" wire with the switch in both modes. With the TPWS connected (and the sensors not present) you will read ~1 VDC. Withe the TPWS bypassed you should read ~4 VDC. If the voltage is less than 3 VDC, the light will remain on.

If you do measure less than 3 VDC, you will need to change the resistiors to 150 ohm, 1/2 watt ones.


I'll try again this weekend thanks.

[linny]

Installed the 150 Ohm resistor harness yesterday and no more light!! Took a 60 mile drive last night and 3 mile work commute today and all is still great!

[Pitt Yaris]

i haven't checked my pressure lately, but everything is stock on mine....the light came on when it got cold out, and hasn't turned off since. car is two months old

[mikenacarato]

add some air

[ivanmadeline]

Can you take a picture of your connector? The part number is the same for 08 and 09 sedans and LBs, so even though the wire colors are different, their functions are identical.

If your connections are in the correct place, try measuring the voltage on the "brown" wire with the switch in both modes. With the TPWS connected (and the sensors not present) you will read ~1 VDC. Withe the TPWS bypassed you should read ~4 VDC. If the voltage is less than 3 VDC, the light will remain on.

If you do measure less than 3 VDC, you will need to change the resistiors to 150 ohm, 1/2 watt ones.

Hey CTScott thank to you the light is gone. The first time the light came on again but when I got home I change the blue and the yellow cable around and the light was on I click the switch and the light is gone. Thanks for all your hard work.:thumbup:

[IllusionX]

Scott, do you have a picture of that light ?

[CTScott]

Scott, do you have a picture of that light ?

It is the one that looks like this:

http://www.carbuyersnotebook.com/tpms_display1.jpg

[IllusionX]

thank you.

[Black Yaris]

so is this latest fix 100% working, with no problems?

[ivanmadeline]

so is this latest fix 100% working, with no problems?


I can let you know tomorrow I just got done changing the resistior to the 150 omh 1/2 watt. I had the 10 ohm that i install the first time and the light would stay off the first day and it would come back on the next day after the first 15 min ride.

[linny]

I put in the 150 Ohm resistor mod on Dec 2 and have had no problems in the ~150 miles I have driven since. I did not do the switch procedure as I do not intend to EVER go back to a TPMS. I personally see absolutely no value in TPMS whatsoever for me.
SO, if I ever buy another new car I will do this all over again!

[ivanmadeline]

so is this latest fix 100% working, with no problems?

Yes it does work the 2nd day in the road no light. With no switch.:clap:

[blacksandiegovitz]

Still working with the 150 ohm resistor modd????

[linny]

It is still working for me!:headbang:

[09TRD]

Just to verify:

If one chooses to do this mod without the switch, the connector remains UNPLUGGED from the TPWS module?

[CTScott]

Just to verify:

If one chooses to do this mod without the switch, the connector remains UNPLUGGED from the TPWS module?

Correct.

[Tiddlygoose]

OK, so I followed the first mod as CTScott knows... Then I followed the corrected 2nd version of the mod. I Left the first switch in the on position, Added a second push button switch with the 3 150 ohm resistors and it worked right up until the time I got up to highways speed. Then the darned light came back on. No amount of changing either switch changes anything at all.

Question. Can the dealer disable the entire TPMS system, even if it costs me? Has anyone had that done or know anything? I always check my own damed tires. I've never had anything like this to fall back on before and with my tire switching situation I'd just as soon loose TPMS all together at this point.

[CTScott]

OK, so I followed the first mod as CTScott knows... Then I followed the corrected 2nd version of the mod. I Left the first switch in the on position, Added a second push button switch with the 3 150 ohm resistors and it worked right up until the time I got up to highways speed. Then the darned light came back on. No amount of changing either switch changes anything at all.

Question. Can the dealer disable the entire TPMS system, even if it costs me? Has anyone had that done or know anything? I always check my own damed tires. I've never had anything like this to fall back on before and with my tire switching situation I'd just as soon loose TPMS all together at this point.

The dealer can't disable it.

Can you take some pictures of your wiring, so I can help you troubleshoot it?

Mine has been running fine disabled (no light) since I posted the updated version on 11/30/08.

[blacksandiegovitz]

The dealer can't disable it.

Can you take some pictures of your wiring, so I can help you troubleshoot it?

Mine has been running fine disabled (no light) since I posted the updated version on 11/30/08.

I haven't even ef'd with the fix yet. I got just about every damn warning light on cause I switched steering wheel , rims, seats, seatbelts. At this point its probaly just easier for me to pull out the gauge cluster and pull the light bulbs out , Lol.

[Tiddlygoose]

The dealer can't disable it.

Can you take some pictures of your wiring, so I can help you troubleshoot it?

Mine has been running fine disabled (no light) since I posted the updated version on 11/30/08.

Cool, I appreciate it. I think at this point I shall wait until it warms up above freezing. I nearly got frostbite on my fingers when I did this a few weeks ago... I will live with the light for now.

[linny]

I am still happily driving around TPWS light FREE!! I followed the 150 ohm procedure without a switch.

[ivanmadeline]

I am still happily driving around TPWS light FREE!! I followed the 150 ohm procedure without a switch.


Like Linny Still no light :thumbup:

[ricktoyota73]

Ok, so on a new project, I should use 130 ohm resistors, correct?
I have a bunch of 20 guage wire. Is that ok to use?
CTScott...how did you figure this shit out?
I have been working in the parts department of car dealers for the last 10 years and, from the things I've seen over the years, you never want to cut the factory wire harness. I will definitely leave enough wire where I can reconnect the SOB, but it still scares the crap out of me. It will be worth it to get rid of the cursed light, though.

[CTScott]

Ok, so on a new project, I should use 130 ohm resistors, correct?
I have a bunch of 20 guage wire. Is that ok to use?
CTScott...how did you figure this shit out?
I have been working in the parts department of car dealers for the last 10 years and, from the things I've seen over the years, you never want to cut the factory wire harness. I will definitely leave enough wire where I can reconnect the SOB, but it still scares the crap out of me. It will be worth it to get rid of the cursed light, though.

110 to 150 ohm resistors will work - Just make sure they are 1/2 Watt.

Cutting into factory harnesses can be dangerous if you don't know what you are doing. I design more complex systems for a living, so I enjoy reverse engineering automotive systems.

[ricktoyota73]

110 to 150 ohm resistors will work - Just make sure they are 1/2 Watt.

Cutting into factory harnesses can be dangerous if you don't know what you are doing. I design more complex systems for a living, so I enjoy reverse engineering automotive systems.

I sell auto parts and I honestly don't understand how half of this stuff works!
Thanks for the info. Hooking it up as soon as we get a weekend above freezing and I can stand to be out in the garage for a while.

[ricktoyota73]

Just curious, if I'm not putting in a switch and don't care if I ever enable the system again, can I just cut and connect the wires to the resistor package instead of using tap splices?

[CTScott]

Just curious, if I'm not putting in a switch and don't care if I ever enable the system again, can I just cut and connect the wires to the resistor package instead of using tap splices?

Yes you can.

I wrote it up with use of the tap splices keeping in mind that many people are not comfortable soldering under the dash (and in relatively close proximity to the passenger air bag).

[ricktoyota73]

So, just using butt connectors not a good idea (uh huh huh huh...I said "butt" huh huh)?

[mikenacarato]

Just curious, if I'm not putting in a switch and don't care if I ever enable the system again, can I just cut and connect the wires to the resistor package instead of using tap splices?

thats what i did and it works fine, i even removed both TPMS modules, one under the dash and one in the paneling behind the trunk. theres a good .02 lbs and weight saved! :thumbup:

[ricktoyota73]

Funny about the weight savings!

[CTScott]

So, just using butt connectors not a good idea (uh huh huh huh...I said "butt" huh huh)?

Butt connectors are fine - Just don't use big ones (unless you like that kind of thing...)

[regal]

When doing this will there still be an OBDII code? I ask because to pass emissions in PA you can't have any OBDII codes.

[CTScott]

When doing this will there still be an OBDII code? I ask because to pass emissions in PA you can't have any OBDII codes.

The TPWS does not report codes over OBDII, so you should be fine. It's data is accessible over the CAN bus, but a Toyota specific communication tool is required to access the data.

[AznGouki]

Does every yaris have it? I have the base with no AC 08. Any way to verify before I start looking for the module?

[Taiyaki]

Ok so to get rid of it without a switch all you have to do it start off with the light not on, turn off the car, unplug the thing, and cut the green and brown wire and connect them to eachother, and leave the harness unplugged?

[gwasabi]

no i think u gotta put resisters in between?

[CTScott]

Ok so to get rid of it without a switch all you have to do it start off with the light not on, turn off the car, unplug the thing, and cut the green and brown wire and connect them to eachother, and leave the harness unplugged?

Jump to post 45 and you'll see the resistor voltage divider. You need to make one of those up. Clipping the wires turned out to not work.

[Taiyaki]

Ok i think ill just put a switch in it.

[CTScott]

Ok i think ill just put a switch in it.


Just to clarify; adding the switch doesn't really make it any easier. If you want to do it without the switch, you build the voltage divider shown below (from page 3 of this thread). You unplug the TPWS connector (and leave it disconnected) and connect the red wire to the red wire show below, the black wire to the white wire shown below, and you connect the green wire to the brown wire below.

The switch method is just for people who run two sets of rims with one of the two sets still having the sensors installed.


http://i372.photobucket.com/albums/oo163/ctscott329/tpws/VoltageDivider.jpg


http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSConn2.jpg


http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSConn1.jpg

[Taiyaki]

Ok so a few days ago I did this. I added a switch. And it worked perfect for a few days. But now the light flashes and when I turn the switch off is stays on (doesn't flash).

[CTScott]

Ok so a few days ago I did this. I added a switch. And it worked perfect for a few days. But now the light flashes and when I turn the switch off is stays on (doesn't flash).

Measure the voltage on the brown wire.

[regal]

I'm not getting any voltage off the brown, white, or red wire, where is the fuse for this thing?

[CTScott]

I'm not getting any voltage off the brown, white, or red wire, where is the fuse for this thing?

It's the ECU-IG 10A fuse.

[regal]

Thanks where would that be located?

[CTScott]

Thanks where would that be located?


In the fuse panel that faces the driver's side floor mat at the bottom left of the dash.

[regal]

In the fuse panel that faces the driver's side floor mat at the bottom left of the dash.

looks like I'm buying an 09 service manual there is no such fuse in that location

[CTScott]

looks like I'm buying an 09 service manual there is no such fuse in that location

24298

[regal]

nothing there but I butch of relays, no fuses

[regal]

are these odd ball fuses or something?

[CTScott]

are these odd ball fuses or something?

You're looking in the wrong place. Lay on the floor and look up at the bottom of the dash (directly under where you are looking). You'll see a plastic panel with the fuse locations. Pull that plastic cover off and the fuses will be visible.

[regal]

found it thanks a bunch

[regal]

but now when I turn my headlights on the instrument panel goes dim, under daytime running lights the dash is illuminated, very odd and can't find anything in the owners manual.

[CTScott]

but now when I turn my headlights on the instrument panel goes dim, under daytime running lights the dash is illuminated, very odd and can't find anything in the owners manual.

That's the normal behavior for the instrument panel lighting - Full bright with headlights off and dimmed, per the knob, with headlights on.

[regal]

That's the normal behavior for the instrument panel lighting - Full bright with headlights off and dimmed, per the knob, with headlights on.

I'll figure out this Toyota eventually. Thanks again.

[regal]

I finally got it to work after cutting about half the waires off, I am using a different 12V source and the voltage divider, the TPMS unit is unplugged. Not pretty but does work. CTScottt mentioned there is a regulated 4V signal coming out of theTPMS uit, I couldn't find one on my 09 only a 6V.

[Yaris Hilton]

but now when I turn my headlights on the instrument panel goes dim, under daytime running lights the dash is illuminated, very odd and can't find anything in the owners manual.

Your Yaris has daytime running lights?

[regal]

Your Yaris has daytime running lights?

yes 09, found it was just the dimmer switch turned off, for some reason the dimmer switch dims the dash only when the headlihts are on.

[Yaris Hilton]

My '07 & 2 '09s have normal headlights that you have to turn on, no DRLs. (Thankfully!) Must be a state law thing.

[Treyz]

Sedans don't get the DRL options like the lifback. My old '07 had them as well as my new '09.

I did the switch today. I had to leave it dangleing because I don't think the quick connects (splicers) made a solid cut through the facotry wires. I'll get to it eventually lol.

[CTScott]

Sedans don't get the DRL options like the lifback. My old '07 had them as well as my new '09.

I did the switch today. I had to leave it dangleing because I don't think the quick connects (splicers) made a solid cut through the facotry wires. I'll get to it eventually lol.



Here's an even easier method that I figured out one day. I just haven't gotten around to writing up a DIY on it:

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSBypassv2.jpg

[Treyz]

So now we are back to three wires? I did the heat shrink and all with the 150ohms.

[CTScott]

So now we are back to three wires? I did the heat shrink and all with the 150ohms.

It's not cutting the VSS and ESS wires (like the original started with). In doing some reverse engineering of the TPWS, I realized that it has a regulated 5VDC output that powers the radio receiver module. Tapping the white wire in pin 5 gives us this regulated voltage, so the resistor voltage divider isn't necessary. Both methods work, but this one is a bit more simple.

[Keith Tinari]

I just took off my rims, I will be doing this in a little to get the light off permanently.

[regal]

I found my 09 to have completely different colors, I used a DMM to find the right wires.

[Keith Tinari]

I re read this thread and realize I am not even close to competent to do this lol.

[regal]

learn how to use a DMM they cost like $6 at harbor freight, use the resistors to split a 12V line to 5V and send to the indicator light.

[CTScott]

I re read this thread and realize I am not even close to competent to do this lol.

Just look at post #115 above. As long as your wire colors/positions match up, it is quite simple, especially if you do the non-switch version. Basically, you clip one wire and tap it to another.

[Liu997]

ehh I did the resistor thing anyway, so basically the resistors was just for a 5v dc?
Doesn't matter soldering is fun :thumbup: Anyways you da man CT

[jonismyname]

i just completed this in 90 seconds with a pocket knife.

it'll take another 30 seconds when i have a piece of tape to finish.

[busdriver]

CT Scott:
Great thread. Using your scematic, I did the fix in 30 mintues.
Thanks!

[bronsin]

Hmm I bought a rim for my Yaris with a useable tire but no sender. What happens if the warning light goes off! Ok to put tape over it?

[CTScott]

Hmm I bought a rim for my Yaris with a useable tire but no sender. What happens if the warning light goes off! Ok to put tape over it?

The light will come on eventually. It doesn't affect anything other than being annoying. You can tape it, or do the mod.

[bronsin]

Now that I read it and understand it, the mod looks good!

[CTScott]

Now that I read it and understand it, the mod looks good!

Make sure you look at post 115. It was my 3rd iteration of the mod, and the simplest.

[bronsin]

Yes I read the whole thing through a few times. (and I may read it some more!) Im used to buying $300 cars and fixing them (well...$300 cars 20 years ago) but this ECM stuff I have no clue. Thanks for figureing this out !

[ricktoyota73]

Thank you for the simple TPMS mod, CTScott!

[birdman]

Hi CT, I had my sensors moved to my aftermarket rims for non snow months. My factory steel rims have the snows with no sensors. In Summer no prob, but in winter the TPWL will start flashing for less than a minute then shut off until I restart the car. Sometimes it will come on and sometimes it wont but it always goes out after flashing. Is this typical?

[birdman]

Oops I said TPWL (tire pressure warning light) when I meant TPMS.

[CTScott]

Hi CT, I had my sensors moved to my aftermarket rims for non snow months. My factory steel rims have the snows with no sensors. In Summer no prob, but in winter the TPWL will start flashing for less than a minute then shut off until I restart the car. Sometimes it will come on and sometimes it wont but it always goes out after flashing. Is this typical?

That's normal. If you store your summer tires somewhat near where you park the car, it will communicate with the sensors and be happy for a while. Once it is away from the tires for a bit, it will realize that it hasn't talked to the sensors and will turn the light on.

[birdman]

Even when I go on long winter trips for several days the light will often start flashing for less than a minute and always go out. Normal too?

[birdman]

There are so many really smart people here clearing every hurdle placed before them that I am awe struck by it. I am very fortunate to have stumbled into this awesome community.

[regal]

I've bought a lot of "stuff" I intended to add/mod to my Yaris, this was the first mod I did. To me it is mandatory. The TPMS is a sales gimmick, nothing more. The batteries in the sensors will eventially go bad, you must have have the ability to swap rims without an idiot light.

[Rick]

Here is another way to implement CTScott's mod to make the TPMS light stay off no matter what. It's electrically identical, quick, easy and leaves no readily observable evidence of "tampering". It's also a reversible mod. You'll need a small side-cutter, a soldering iron and about 10 minutes of time.

The three pictures should say it all.

[CTScott]

^Nice!

Totally out of view for those worried about it being seen when they go in for warranty work.

[Treyz]

I gotta do this .. mine still doesn't work right and this is with the resistors. Not working for some reason, but Domo blocks the view of it so it's not really annoying.

[yarisugi]

Thanks to them, I was able to make mine with a switch.

http://i279.photobucket.com/albums/kk125/LookOnTheBrightSide/Yaris/TPWSswitch2.jpg

http://i279.photobucket.com/albums/kk125/LookOnTheBrightSide/Yaris/TPWSswitch3.jpg

[docB]

:thumbup:I did the latest tpms light disable as per post by yarisugi. I got a small DPDT from Radio Shack. Good thing I had a tiny pair of side cutters. I can flip the switch back and forth with the correct results every time. I did this and then put on some 14 x 6 BBS wheels on with 185/60-14 wheels and tires. The car handles much better than with the 15" steelies. I can chirp the tires now at will. It likes the smaller tires and lower gearing. Ya the speedo is off now, but I get 15k a year on my lease. Thanks to all from this post for the awesome, accurate work and reporting. I'll try and post a photo of the car soon.
doc

[birdman]

I'm finally ready to do this fix. The switch option requires that the snipped brown wire that is attached to the connector be grounded, while the upper part is wired to the switch. Right?

[CTScott]

I'm finally ready to do this fix. The switch option requires that the snipped brown wire that is attached to the connector be grounded, while the upper part is wired to the switch. Right?

No, there is not a ground connection. With the switch, you are either leaving the brown wire connected or connecting it to the +5V line.

[birdman]

In post #115 the diagram shows the brown wire is cut. The upper part you have pictured connected to a blue line going to one side of the switch. On the other side of the switch there is a blue line that splices to a white wire. The portion of the brown wire that is attached to the connector you show a blue line attached to it. That blue line terminates at a black dot. If the black dot doesn't indicate a ground then what does it indicate? There is no mention of a +5v line in that diagram. This simple diagram isn't simple to me.

[birdman]

I just did a search of this entire thread and there is no mention of a +5V. So how am I supposed to know what a +5v is?

[CTScott]

In post #115 the diagram shows the brown wire is cut. The upper part you have pictured connected to a blue line going to one side of the switch. On the other side of the switch there is a blue line that splices to a white wire. The portion of the brown wire that is attached to the connector you show a blue line attached to it. That blue line terminates at a black dot. If the black dot doesn't indicate a ground then what does it indicate? There is no mention of a +5v line in that diagram. This simple diagram isn't simple to me.


The black dots just indicate connection points. What the diagram below shows is that the "common" for the switch goes to the wire that heads up to the cluster and the two "poles" of the switch connect to the brown wire (for normal operation) and the white wire (for bypass operation). So, the switch is simply connecting the wire up to the cluster to the output of the module (the brown wire) or +5V (the white wire).

In your post where you mentioned ground, I just wanted to clarify that there is no ground connection with the switch, as making such a connection would instantly pop a fuse.


http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSBypassv2.jpg

[birdman]

The "common"? "Bypass operation"? I'm not familiar with such terminology. If you would could please explain it using "man in the street" terminology. Like saying "white wire" rather than complicating it by adding the +5v term.

[birdman]

Again. If the black dot connected to end of the blue line that connects to the brown wire attached to the connecter is a connection then what is it connecting to? Not the blue line going to the switch. I think CTScott is so technically advanced it is hard for him to simplify his explanations to the point where everyone can understand them.

[CTScott]

Again. If the black dot connected to end of the blue line that connects to the brown wire attached to the connecter is a connection then what is it connecting to? Not the blue line going to the switch. I think CTScott is so technically advanced it is hard for him to simplify his explanations to the point where everyone can understand them.

LOL - That's the problem with talking to other engineers all day.

The lines with the black dots represents the switch. The switch is a single pole, dual throw switch, which simply means that it takes one wire and connects that wire separately to two other wires. Depending on which direction the switch is flipped in, it connects the center to one side or the other. The picture below shows an example of a SPDT switch. You would attach the brown wire going up to the cluster to the center of it, and then the other side of the brown wire to one of the outer pins and the white wire to the other outer one.



http://www.cascadesurplus.com/catalog/images/SPDT_on_on_Switch1.jpg

[birdman]

So all 3 dots are switch connection points with the brown from the connector connecting to the center post?

[CTScott]

So all 3 dots are switch connection points with the brown from the connector connecting to the center post?

Correct. That was a typo - I meant single pole, dual throw...

[birdman]

How long do the wheel mounted TPMS sensors last before their batteries fail?

[CTScott]

How long do the wheel mounted TPMS sensors last before their batteries fail?

The service manual doesn't say. It just mentions that the sensors' "grommets" must be replaced every 10 years.

[birdman]

This guy knows everything. Sheese!

[birdman]

Now I'm going switch hunting at the auto parts store.

[yarisugi]

I got my switch from radioshack, might be cheaper than auto parts.
Yes, CTScott knows everything - I mean EVERYTHING! So glad he is here and owns a Yaris.

[birdman]

Imagine the hours CTScott must devote preparing all this material for our benefit.

[Revsson]

Imagine the hours CTScott must devote preparing all this material for our benefit.

What's CTScott doing answering these posts? :iono:
He's gotta get back to working on the Yargauge! :mad:

j/k

Yes, he is definitely a great asset to this community. :clap:

[Clintondmb]

Many thanks for this mod. this will save me serious $ whenI put rims on my '08 LB.

[darkMINI]

Thanx as well, works great!
One problem I encountered was using the tap-splice connectors I didn't get all the way through the wire insulation the first time. Had to strip a small spot of the insulation from the wires to get a connection. The darn wires are so tiny.

[Midnight Drifter]

*post 115*

So just... find the brown wire, cut it, splice the side going OUT from the plug unto the white wire and leave the brown wire going INTO the plug capped?

[bB2NER]

I just put a piece of black tape over the light when I changed the rims. Didn't feel like cutting wires.:iono:

[CTScott]

So just... find the brown wire, cut it, splice the side going OUT from the plug unto the white wire and leave the brown wire going INTO the plug capped?

Correct.

[mario98c]

http://img89.imageshack.us/img89/4779/img0307g.jpg

[auxmike]

http://img89.imageshack.us/img89/4779/img0307g.jpg

CT Scott, is this this the way it's done in an easy to understand pic?

[CTScott]

Yes.

[derickveliz2]

mmm I should get this done! too much time playing with sound system!

D.

[auxmike]

Yes.

OK then.
SO, this method does NOT require the the light to be off pre procedure OR that the wheels/sensors to be mounted on or near the car before starting, right? Even if you start out with the light on, it does'nt matter this way.
Is this all true?
Thanks!

[CTScott]

OK then.
SO, this method does NOT require the the light to be off pre procedure OR that the wheels/sensors to be mounted on or near the car before starting, right? Even if you start out with the light on, it does'nt matter this way.
Is this all true?
Thanks!

That is correct. This mod actually just disables the warning light, which is why the initial state before doing the mod does not matter.

The TPWS is completely independent of all other systems on the car. It actually uses legacy ISO-9141 comm, rather than CAN bus, so the ECM doesn't even have the ability to talk to it.

[hackenfort]

CTScott,

Just wanted to say THANK YOU!

This is the first thing I did when I bought my new Yaris a few months back.

Sure beats taking the inst cluster out and covering the led for the light!

so THANKS AGAIN!

Kevin

[zelig]

That is correct. This mod actually just disables the warning light, which is why the initial state before doing the mod does not matter.

The TPWS is completely independent of all other systems on the car. It actually uses legacy ISO-9141 comm, rather than CAN bus, so the ECM doesn't even have the ability to talk to it.

So the light is the only onboard indicator of TPMS state? Is there a service tool to interface with the TPMS and read/report status? I suppose I'm basically wondering if there's any advantage to tricking the system into seeing a "good" state vs just disabling the warning light.

Also, is there any identifier such as a part number on the TPWS ECU?

I'm really excited to try this!

[CTScott]

So the light is the only onboard indicator of TPMS state? Is there a service tool to interface with the TPMS and read/report status? I suppose I'm basically wondering if there's any advantage to tricking the system into seeing a "good" state vs just disabling the warning light.

Also, is there any identifier such as a part number on the TPWS ECU?

I'm really excited to try this!

The TPMS is completely independent of the ECM, but the Toyota Techstream tool can communicate with it via the ODB port. The TPMS is the only system on the Yaris that does not communicate over CAN BUS, but rather just communicates via the older ISO-9141 spec. So, there really isn't any advantage to tricking the system instead.

[A-Dingo-Ate-My-Baby]

info

I did this mod by opening up the tmps module, pulling
the pcb, soldering in 3 wires, cutting one, and using a switch
screwed into the face, as in the pics a few posts earlier
----


One note:

you can easily pull the tpms pcb by using a small flat blade screwdriver on the
small plastic tabs on the gray tpms cover....
there is no need for any tools other than that. the tpms cover pops right
off and the pcb slides right out. super easy.

[2mtech]

Thank you, Scott! Did the no switch option mod tonight; bye-bye light that irritated me all weekend driving through VA :headbang:

[hwnstyle21]

Thank you for this DIY.

[keona]

Thank you Scott!!!

[CrankyOldMan]

Thanks to them, I was able to make mine with a switch.

http://i279.photobucket.com/albums/kk125/LookOnTheBrightSide/Yaris/TPWSswitch2.jpg


I'm putting winters on this week, just did the mod yesterday. I still can't find my digital camera, but the pics/schematics shown are plenty to get it done.

[auxmike]

I just did this in about ten minutes. You don't need remove the whole black box, remove the connector plug with the wires in it and then carefully pry the clips up on the cover surrounding the connector and remove it. After that the board slides straight out. I just cut one pin lead and soldered it to the one next to it as pictured above. Lights out now! I've been living with that for over four years......
PS It appears the top of the green PC board is conformal coated to protect against moisture and dust. It looks like it's UR vs. the Humiseal acrylic and it's handbrushed on..

[CodyTheBody]

Here's an even easier method that I figured out one day. I just haven't gotten around to writing up a DIY on it:

http://i372.photobucket.com/albums/oo163/ctscott329/tpws/TPWSBypassv2.jpg



So this method replaces the very first post of this entire thread? I'd like the ability to switch back and forth between wheels. Put some different rims/tires and had the TPMS light come on and stay on.

[CTScott]

So this method replaces the very first post of this entire thread? I'd like the ability to switch back and forth between wheels. Put some different rims/tires and had the TPMS light come on and stay on.

Correct.

[bewley]

Hey, not to hijack such a useful thread but I did want to tell you guys that Costco will reprogram sensors for nothing, according to the tires manager with whom I spoke today. Walmart will do it for $20 for the whole vehicle: http://www.walmart.com/cp/Tires-Services/495845. The dealership charges much, much more, as CTScott mentioned in his original post. Just wanted to throw this out there if anyone is disabling because they swap tires seasonally and considered the price of programming prohibitively expensive.

[docB]

This thread is all about not having the annoying light on the dash when you don't have wheels with the sensors on your car. They are a needless joke to begin with.

[bewley]

Of course they aren't necessary and I understand the purpose for the thread. But I would imagine that my information might benefit a few people who might be reading this thread because they think reprogramming when swapping will be costly... since it is costly if you reprogram at a dealership.

[jimmykicker]

Hey guys. I have a 2009 Scion (toyota) xb. I have had this light annyoying the bejesus out of me for 2 years....in fact since I bought it. I think the dealer didn't bother putting them back in when they installed new tires when I purchased it. Seeing the dealer was 150 miles from where I bought it, I just left the light on. Question is, does anybody know if this fix will work on my car too? Are the wires the same? Is it in the same relative location? I can't find any info on where the box is in my car. Any info is appreciated. Hate to hijack the forum as I don't own a Yaris, but this is great information and looks super easy. Thanks.

[CTScott]

Hey guys. I have a 2009 Scion (toyota) xb. I have had this light annyoying the bejesus out of me for 2 years....in fact since I bought it. I think the dealer didn't bother putting them back in when they installed new tires when I purchased it. Seeing the dealer was 150 miles from where I bought it, I just left the light on. Question is, does anybody know if this fix will work on my car too? Are the wires the same? Is it in the same relative location? I can't find any info on where the box is in my car. Any info is appreciated. Hate to hijack the forum as I don't own a Yaris, but this is great information and looks super easy. Thanks.

Looking at the EPC, the part number for your TPMS ECU is unique to the 07+ XB (89769-12030). I only have the 06 XB service manual, and since the TPMS wasn't added until 07, it's not covered. If you can track down the TPMS section of the service manual or at least the instrument cluster electrical wiring diagram, then I can tell you if this method will work. As far as location goes, the EPC shows a very poor representation of the location, but I think it is showing it as being behind the lower part of the C-pillar cover.

[CrankyOldMan]

I had forgotten about having done this mod, until the light came on last week. Of course, I should have expected it since my winter tires don't have TPMS stems, but it still took me by surprise. Strangely enough, all I could think of when it came on, was of an anthropomorphic Yaris screaming, "I can't feel my tires! AAAAUGH!"

[jimmykicker]

Looking at the EPC, the part number for your TPMS ECU is unique to the 07+ XB (89769-12030). I only have the 06 XB service manual, and since the TPMS wasn't added until 07, it's not covered. If you can track down the TPMS section of the service manual or at least the instrument cluster electrical wiring diagram, then I can tell you if this method will work. As far as location goes, the EPC shows a very poor representation of the location, but I think it is showing it as being behind the lower part of the C-pillar cover.

Now I am a bit confused about that. There was no 2007 Scion xb. 2006 models ran late, and they didn't introduce the new style to 2008.

Let me see what I can find out about the wiring diagram. Shouldn't be too hard to come up with. I'l probably just buy a service manual. It's the only car I have never bought one for. Thanks.

J

[CTScott]

Now I am a bit confused about that. There was no 2007 Scion xb. 2006 models ran late, and they didn't introduce the new style to 2008.

Let me see what I can find out about the wiring diagram. Shouldn't be too hard to come up with. I'l probably just buy a service manual. It's the only car I have never bought one for. Thanks.

J

In the EPC I was looking at build date, so the 2007's were really 2008's for the US.

[jimmykicker]

Ah...gotcha. I will see what I can do. Thanks!

[carlisle737]

Hi Guys, I'm hoping this thread is still alive. I need to bypass the tpms for my 2008 4Runner and my wire colors are really different than what's been described. My hot lead is black with a red stripe. My red (with a yellow stripe) is 12v and I have 2 pinks, one with a black stripe and the other with a yellow stripe. I've attached the photos to see if anyone else has run into this tpms harness where every wire has a stripe of some sort. Any help is deciphering this wire mess will be greatly appreciated.

Thanks.
http://images2.snapfish.com/232323232%7Ffp54378%3Enu%3D337%3B%3E366%3E944%3EWS NRCG%3D3477467%3A%3A7345nu0mrj

http://images2.snapfish.com/232323232%7Ffp543%3B%3A%3Enu%3D337%3B%3E366%3E944% 3EWSNRCG%3D3477467%3A%3A8345nu0mrj

[yarisugi]

^first post LOL.

[CTScott]

Hi Guys, I'm hoping this thread is still alive. I need to bypass the tpms for my 2008 4Runner and my wire colors are really different than what's been described. My hot lead is black with a red stripe. My red (with a yellow stripe) is 12v and I have 2 pinks, one with a black stripe and the other with a yellow stripe. I've attached the photos to see if anyone else has run into this tpms harness where every wire has a stripe of some sort. Any help is deciphering this wire mess will be greatly appreciated.

Thanks.
http://images2.snapfish.com/232323232%7Ffp54378%3Enu%3D337%3B%3E366%3E944%3EWS NRCG%3D3477467%3A%3A7345nu0mrj

http://images2.snapfish.com/232323232%7Ffp543%3B%3A%3Enu%3D337%3B%3E366%3E944% 3EWSNRCG%3D3477467%3A%3A8345nu0mrj

The wire colors are different and the TPMS ECU has a different part number, that is unique to the 4Runner, so I would need to see the wiring diagrams for the 4Runner to be able to tell you if the procedure is the same.

[yarisugi]

Don't know if 2004 is same as 2008.
Does this help, CTScott?

[CTScott]

Don't know if 2004 is same as 2008.
Does this help, CTScott?

Different - That one has 16 pins whereas the 2008 has 12.

[carlisle737]

Any suggestions on the best site to buy the wiring diagrams from?

[yarisugi]

aw crap. oh well. Thought you had the EPC for all the Toyotas. hehe.

After Googling I came across this link (http://www.toyota-4runner.org/4th-gen-t4rs/50252-tpms-light-bypass-switch.html).
Some member said it worked on their 2007 4Runner, is 2007 and 2008 different?

@carlisle737 - trade in your 4Runner for a Yaris.

[carlisle737]

I've seen so many posts for the 4runner bypass, but every post has the wiring you guys describe for the Yaris (and pretty much every other Toyota). I think Toyota decided to use all there spare wire stock in the 08 4runner. This vehicle has thrown me more curves that I can swing at.

But I have a feeling a Yaris couldn't pull my boat, so I'll have to make due.

Thanks for the comments though. I once again have hope that the light will go away.

[CTScott]

aw crap. oh well. Thought you had the EPC for all the Toyotas. hehe.

After Googling I came across this link (http://www.toyota-4runner.org/4th-gen-t4rs/50252-tpms-light-bypass-switch.html).
Some member said it worked on their 2007 4Runner, is 2007 and 2008 different?

@carlisle737 - trade in your 4Runner for a Yaris.


08 is different, as that 07 diagram still shows a 16 pin connector.

There are a bunch of ebay vendors that sell copies of the Toyota service manuals for about $10.

[BobGood]

Thanks, CTScott, for providing the bypass of the TPWS system on my 2008 Yaris. The lights out now. I had damaged my TPMS valve stem so I ordered one off of Ebay with the exact same serial number as my old one but once I had it installed at a local tire place the light remained on. I called the Service Dept for the closest Toyota dealership near me (an hour and half away from where I live) and was informed that the TPMS needed registering with the TPMS ECM which would cost me $90.00. Then I read in this thread that the battery in the TPMS would give out after 7 years or so and would then need to be replaced ($130.00 x 4 + $90.00 equals quite a bit of money). I then decided to try your suggestion in post #115 and it worked...and simple to do as well.

So, thanks again. :).

BTW, I registered here just so I could thank you.

Best regards,

Bob

[dave van muyden]

I tried this but by accident grounded the red wire now abs light on no powersteering and speedo doesnt work

[CTScott]

I tried this but by accident grounded the red wire now abs light on no powersteering and speedo doesnt work

You popped the 10A ECU-IG fuse, which is in the fuse panel under the bottom of the dash by the hood release.

[xiaoya]

I tried the mod today but with no luck. The warning light is still on after I connected brown to white. Please see the attached pic. My yaris is a 2008 one.

Thank you.

[CTScott]

I tried the mod today but with no luck. The warning light is still on after I connected brown to white. Please see the attached pic. My yaris is a 2008 one.

Thank you.

That is because you did not follow the instructions. You connected the wrong side of the brown wire to the white wire. You need to cap off the end that comes out of the connector and instead tap the end that heads up to the cluster to the white.

[xiaoya]

Oops, I got it totally opposite. My wife is driving the car today, will fix it tomorrow.

Thank you very much CTScott

[maui]

I was just studying this TPMS sensor solution. Comparing photo #2 the the color coded diagrams, it looks like one just clips the brown wire and splices it to the white one, and that this would be easy using one of those press down splicers, and of course taping off the end of the other brown wire.

Please let me know if this interpretation is correct. Or if anyone has a picture of the completed splice please post.

Since this is reversible it looks like an easy solution.

Thanks,

Maui

[hatchbackkid82]

Will this work if you have a bad TPMS? My light flashes and stays on.

I'd rather disable it all together, stupid shop wants $320:thumbdown: for one sensor

[CTScott]

Will this work if you have a bad TPMS? My light flashes and stays on.

I'd rather disable it all together, stupid shop wants $320:thumbdown: for one sensor

Yes it would make the light go away.

[hatchbackkid82]

I did this over the weekend when i had my tires replaced. I had them pull the sensors out too. Worked like a charm. Thanks guys

[tradergordo]

I did this fix on a 2010 Yaris and it worked perfectly, so thanks a lot! But now I want to do the same on a 2014 Yaris (4 door hatchback) but I don't see the TPMS ECU behind the glove box. Does anyone know where it is? I couldn't find any free repair manuals online like there are for older models, cheapest one on eBay is $60...

[CTScott]

I did this fix on a 2010 Yaris and it worked perfectly, so thanks a lot! But now I want to do the same on a 2014 Yaris (4 door hatchback) but I don't see the TPMS ECU behind the glove box. Does anyone know where it is? I couldn't find any free repair manuals online like there are for older models, cheapest one on eBay is $60...

There is not a simple solution for 3rd gen (2012+), as the TPMS ECU now sends the info to the cluster via CAN bus message, rather than by a simple single line driving an LED.

The third gens do allow you to easily relearn the TPMS sensors by simply pressing a button, so the simplest solution is to have a second set of sensors in your alternate rims.

[tarkus]

Is there not a way to short out something at the wheel/sensor end before it gets encoded onto the CAN buss?

This looks like yet another case of unnecessary electronic complexity being put into cars, which means more things to go wrong. I work in the very high tech semiconductor/software industry myself, so I'm not against advances in technology as such, just against technology which causes more problems in the long run.

Sent from my LG G2 with CM13 using Tapatalk

[fj40dave]

Just did this mod

Cut the brown, press-splicer brown and white....worked perfect (after I plugged the connector back into the box - duhhhh)....

Thank you - this place rocks!

(I chose to not have the sensor replaced after I heard it bouncing around in the left front tire and would have to pay $60 for a replacement)

[Juanalexis21]

Hello friend, let's see if you can help me! I have a 2010 Yaris sedan and I changed my tin rims for type S, I did not change the TPMS sensors of my original rims but the emergency rubber still has the factory sensor. The type S rings have their original TPMS sensors but the vehicle that had them. How can I configure the new sensors in my vehicle?

I know it's not a blog but I hope I can help. Grateful!!!

Enviado desde mi SM-N910W8 mediante Tapatalk

[Kawiman]

Sorry. I didn't read through the hundreds of posts. Just skimmed through and I didn't see that anyone had done what I did on my "09 Tacoma and '10 Yaris.
I removed the instrument cluster. It's very simple and just placed a double folded portion of electrical taped under the gauge face plastic film. Done.
This way nothing is eliminated if years from now you or the next owner wants the system in use.
It looks like the light was never there.

[CrimsonEclipse]

My apologies for resurrecting an old thread but I am having a problem with my TPMS on a 2011 Yaris.

The problem is, all of the pictures posted were on PhotoBucket and they purged all of their free user pictures.

The only pics lift are of Rick's on post #138.

I can happily try this one but I'd like verification that it worked from someone.

Also, would disabling the TPMS show up in the OBD2 scan?

thanks!

[Maui Paul]

You do need to keep the connector plugged in (with those two wires cut) to sucessfully do the mod. If you just unplug the connector, the TPWS light will immediately come on and will stay on until it is plugged back in.

Cutting those two wires fools the Tire Pressure Warning System into thinking that the car is not moving and the engine is not running. The TPWS will not report an error if it doesn't hear from the tire sensors as long as the car is not rolling and the engine is not running.

We have the light on and are happy to just disable the system by cutting the wires. Someone said it only works if no light is on which is not the case here.
Can someone suggest a way to get the idiot light off AND disable the TPWS system please?

[mrgodai]

We have the light on and are happy to just disable the system by cutting the wires. Someone said it only works if no light is on which is not the case here.
Can someone suggest a way to get the idiot light off AND disable the TPWS system please?

post #115 picture on the left will do it

[apmatzen]

Does this work on a 2016 Yaris?

[Walsh11]

I have a 2013 Yaris, anyone please tell me how to disable this abomination system lol. thanks

[Walsh11]

HELP LOL

[CrimsonEclipse]

I have a 2013 Yaris, anyone please tell me how to disable this abomination system lol. thanks

Dude...

Post #138