I've got 2 P28 ECUs that won't flash the check engine light and the problem is in the ECU. Can someone give me some tips on where to look/test on the circuit board in order to troubleshoot this issue?

 

What do you mean won't flash the check engine code? Does it just stay solid all the time or what is exactly happening?

Are you jumping the service connector properly?

 

Yes, I jump the connector with a switch I have built into my harness. I use my car to verify all ECUs I chip before giving them to my customers. The 2 particular ECUs do not send the signal to the CE light so the problem is on the circuit board.

 

I replied on pgmfi.org about this. Just click the link I posted in that thread and look at the schematic. It has everything you need to test the circuit completely.

 

Got it, thanks

 

HRTuning,
i have not been able to open pgmfi.org. I cannot see the link you posted. can you post a link to it. I am having a problem with a P28 that throws the IAC code 14. I need the schematic to the board. I believe i found the problem but would like to see the Board Shcematic anyway. Thanks.