Ok a little background info... I'm trying to run a 03 ECM (off an ABS equipped sunfire) on a 04 ecotec without ABS. The car shifts hard and will never shift into fourth (stays in third), nor will the lock up torque converter kick in. Plus it throws a couple of transmission related codes. One code stating the car is not starting in the correct gear.

I hooked HPT up to it and ran the scanner and found something odd. When reviewing the PRNDL indicator, it shows 136 - ??? when the car is in park, reverse or neutral, and D3 when it's in 4, 3, 2, or 1.

At first I thought it might have been a bad ECM. So I got another (just happened to be off another 03 ABS equipped car. cavalier this time though). And same exact thing.

BUT, when I use a 04 ECM that came out of a non-ABS equipped cavalier it works perfect. No codes, and the HPT scanner shows P in Park, R in Reverse, N in Neutral, D4 in drive, and so on.

Only thing I can think of is something to do with having/not having ABS? Has anyone else ran into issues with this? Or tried an ECM off a non-abs car on an abs equipped car?




http://jbok.org