That does sounds like it could be the data wires. Check to see if you have continuity from the OBDII data wires all the way back to the ECM data wires.
Okay I ohm'ed all the OBDII wires:
OBDII pin 6 | tan/black strip | High speed GMLAN serial data + | Goes to Power Steering, C2, pin 1 (C2 is the grey, 6 pin connector with the small wires) |
OBDII pin 14 | tan | High speed GMLAN serial data - | Goes to Power Steering, C2, pin 2 |
Power Steering, C2, pin 4 | brown/white strip | High speed GMLAN serial data + | Goes to BCM, J2, pin 1 (J2 is the white & blue vertical connector closest to the center tunnel) |
Power Steering, C2, pin 5 | brown | High speed GMLAN serial data - | Goes to BCM, J2, pin 19 |
BCM, J2, pin 2 | tan/black strip | High speed GMLAN serial data + | Goes to PCM, C1, pin 1 (C1 is the blue connector on the PCM) |
BCM, J2, pin 20 | tan | High speed GMLAN serial data - | Goes to PCM, C1, pin 2 |
All the wires checked out. Put it back together, and
it runs!
I'm not sure if disconnecting my AEM AFR gauge fixed it, or if reconnecting the electrical connectors made a difference. (I am guessing the latter)
I was able to hook up HP Tuners, and it was able to read data.
Thanks everybody who helped me with this.
Lonny told me the BCM doesn't need to be reprogrammed, and
that was great information.
It only
cost me $45 for a used BCM. My new BCM was from a 2006 Cobalt with manual windows, 2.2L engine, and the old BCM was from a 2006 Cobalt SS, 2.0L SC engine, with electric windows.
I'm so HAPPY! I missed today's autocross
but my car runs now :}
Happy, happy, happy!