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View Full Version : I finally cracked the Odometer and SRS ECU code

CTScott
09-16-2012, 11:53 PM
One can purchase very expensive, off the shelf, systems for reprogramming the mileage in a cluster and for resetting the "black box" data in the SRS ECU after a crash, where the airbags deploy. I decided to forgo the expense and try to develop my own.

In both ECUs the data is stored in a EEPROM on circuit board of the device. In the picture below, of the inside of the SRS ECU, the EEPROM is circled.

http://i372.photobucket.com/albums/oo163/ctscott329/Misc%20Yaris/SRSECU.jpg

When I finished repairing my latest project Yaris (AKA Crashy2), I found that even after resetting the SRS ECU's stored codes (DTCs) with my TechStream tool, the SRS light still remained on on the cluster. After doing a bit of research I found out that the light remains lit because the SRS ECU stores data when a crash occurs, where the airbag(s) deploy. Normally a repair shop simply replaces the SRS ECU along with the airbags, but clearing the data from the EEPROM will also correct the issue (and there are quite a few vendors on eBay who will do this for a fee).

I pulled the SRS ECU from my 09 Yaris and read the EEPROM. I compared the data with the data from Crashy2's SRS ECU and cleared the locations that differed. After doing so and reconnecting Crashy2's SRS ECU, the SRS light now lights up for a couple of seconds, when the ignition is turned on, and then goes off (which is the normal behavior).

After building a rig to work with the EEPROM from the SRS ECU, I decided to do some experimentation with the instrument cluster (of which I have been amassing a collection of, when I find good deals on them). The cluster turned out to be quite a bit trickier to crack, but this weekend I finally did so.

Here's an 08 cluster that I started my experimentation with:
http://i372.photobucket.com/albums/oo163/ctscott329/Misc%20Yaris/08Cluster.jpg

Once I figured out how the data was encoded, I found that I could change to value to whatever I wanted:

http://i372.photobucket.com/albums/oo163/ctscott329/Misc%20Yaris/08Cluster242.jpg

http://i372.photobucket.com/albums/oo163/ctscott329/Misc%20Yaris/08Cluster209K.jpg


I could then also take a completely different cluster and program it with the same mileage as my original experimental cluster:

http://i372.photobucket.com/albums/oo163/ctscott329/Misc%20Yaris/09Cluster.jpg


Tampering with the odometer on a vehicle is about as illegal as it gets, but swapping a vehicle's cluster with one with lower mileage achieves the same effect, so it is kind of handy being able to reprogram clusters for those desiring to swap theirs out for one of a different year (i.e. from the 06-08 white cluster to the 09-11 orange one), or with different features (i.e. tach).
edmscan
09-17-2012, 12:21 AM
Now if you can figure out how to make the gas gauge go up electronically ... hmmm, I like that idea of free gas. But what you have posted is pretty cool by itself.
eTiMaGo
09-17-2012, 12:43 AM
If only Ferris Bueller had known Scott... ;) Excellent work sir!
yarisugi
09-17-2012, 01:56 AM
Whoah! That's awesome! Can you make alphabets instead of numbers too? :)
eTiMaGo
09-17-2012, 03:45 AM
^ 80085?
yarisugi
09-17-2012, 04:02 AM
^you dirty man, you! :tongue:
Klink10
09-17-2012, 08:09 AM
Nice work CT.
pennyracer
09-17-2012, 07:44 PM
so can i puchase this item from you ?
CTScott
09-17-2012, 09:15 PM
so can i puchase this item from you ?

Kind of - My services to clear an SRS ECU or reprogram a cluster are available.
pennyracer
09-17-2012, 10:22 PM
okay i will contact you when i need to do the gauge cluster
jack black
12-21-2014, 10:15 PM
CTScott,
Is your method similar to this: http://www.instructables.com/id/Odometer-Reprogramming/step9/Read-Odometer-Information/ ?
Did you have to desoldier the EEPROM?
CTScott
12-21-2014, 10:24 PM
CTScott,
Is your method similar to this: http://www.instructables.com/id/Odometer-Reprogramming/step9/Read-Odometer-Information/ ?
Did you have to desoldier the EEPROM?

That is just a method for reading the data. There is quite a bit more to reprogramming one with the correctly coded data (which is why the software to do so is so dang expensive). I do remove the EEPROM when programming one, as leaving it in circuit can cause data to not be read or written correctly.
jack black
12-21-2014, 10:32 PM
If you read the whole thing, he used free PonyProg software to read and write to EEPROM.
CTScott
12-21-2014, 11:27 PM
If you read the whole thing, he used free PonyProg software to read and write to EEPROM.

Correct, but reading and writing is the easy part. Correctly modifying the data is the key part. The one he does in that link is an old and easy one (especially with the 9346, 8 pin DIP, instead of a surface mount SOIC or TSSOP. The TSSOPs on some of the new Toyota and Lexus cars are so hard to remove and resolder, as the pin spacing is half of the SOIC pin spacing.

The more modern, the more complex for the coding, and every model of Toyota vehicle that I have done has been slightly to completely different.
bronsin
12-22-2014, 07:39 AM
I work on boards under a microscope for a living and am NASA certified.:headbang:

Just had to throw that in there....:biggrin:
CTScott
12-22-2014, 09:21 AM
I work on boards under a microscope for a living and am NASA certified.:headbang:



Just had to throw that in there....:biggrin:


Nice! You're hired.
ebaut
12-22-2014, 08:30 PM
How hard is the swap Scott? I'm not a big fan of the orange one on my 09, i like the 08 better.
CTScott
12-22-2014, 08:39 PM
How hard is the swap Scott? I'm not a big fan of the orange one on my 09, i like the 08 better.

Swapping is very easy - Pull the lower dash trim off (with your hands), slide back the speedometer trim, and remove two screws and two connectors to swap out the cluster. The only issue for swapping an 08 one into an 09 is that ABS was not that common prior to 09 and also if you have cruise control, you will lose the indicators with an 08 cluster. Your other option for 09 is to change the orange LEDs to another color. Like this: http://www.yarisworld.com/forums/showthread.php?t=45129
ebaut
12-23-2014, 12:02 AM
Thx Scott, im handy with a soldering iron. I have actually swapped some LED's on some guitar pedals. Actually the first time I did it, i put a blue LED on a pedal that almost blinded me. That pedal would light my whole bedroom blue while i had the lights off.
Now I know what the sight friendly limits are, at least for my own eyes.

I might try the mod...

Is the European cluster on the 10's and 11's LB's nicer looking?
CTScott
12-23-2014, 12:30 AM
Thx Scott, im handy with a soldering iron. I have actually swapped some LED's on some guitar pedals. Actually the first time I did it, i put a blue LED on a pedal that almost blinded me. That pedal would light my whole bedroom blue while i had the lights off.
Now I know what the sight friendly limits are, at least for my own eyes.

I might try the mod...

Is the European cluster on the 10's and 11's LB's nicer looking?

No. It is the same unless you use a digital European one (which is green).
bronsin
12-23-2014, 07:27 AM
Nice! You're hired.

Im ready to go!:thumbsup:
Dodge Aries K
10-27-2016, 02:15 AM
Sorry for the bump from the dead, but will your equipment work to reprogram a 3rd gen cluster? I want to get the SE gauges for my car but want the odometer to work properly.
Garth g.
10-27-2016, 02:50 AM
When I see this, it makes me want to keep doing stuff to my car. Very cool stuff, off topic question... In a two door 07 what interior can u take from 08?09?10?11?
12?(door panels seats or anything else?)