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

[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.

[bB2NER]

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

[mario98c]

[auxmike]

Originally Posted by mario98c

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

[CTScott]

Yes.

[auxmike]

Originally Posted by CTScott

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]

Originally Posted by auxmike

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]

Originally Posted by CTScott

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]

Originally Posted by zelig

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.

[derickveliz2]

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

D.

[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

[hwnstyle21]

Thank you for this DIY.

[keona]

Thank you Scott!!!

[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..

[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.