Hey there, in the process of rewiring a Jimmy that will be used offroading, curious if anyone knows the pins the ECM uses to know the anti theft checks out, my goal is to test the signal using is oscilliscope or logic analyzer and see what is happening there, then simulate the signal right before the ECM with an Arduino or another microcontroller. Then I could scrapt the entire theft system, does anyone see any issues or easier solutions? My goal is no anti theft shanagins left anywhere on the vehicle.

 

I applaud your efforts. What year is your Jimmy? Perhaps someone has the GM Service Manual with the schematics you would need.

 

Interestingly enough, on youtube there is some guys who have videos of disabling the vats on LS engine... I tried it on the Jimmy, (2002) it worked, simply unplugging the BCM while the vehicle is running disables the ECM from looking for the anti theft go ahead message the BCM uses. Only issues is you need to have access to a running vehicle to do this. Fortunately I did. Problem solved!

 

The anti-theft can be programmed out by pretty much anybody who custom flashes PCMs.