Simple steps to tuning your 96 Grand Prix.

Purchase a PCM from a 1997 Lumina

Step 1
Disconnect battery.

Open PCM case in the engine near radiator passanger side just before the coolant overflow tank.

Disconnect PCM plugs and remove 96 GP PCM

Inspect bottom plug (clear) for a red wire in pin#33 or pin#35

If Clear Pin#33 is red wire see step 2
If Clear Pin#35 is red wire skip step 2, goto step 3

Step 2
Place red wire from Clear Pin#33 to Clear Pin#35
Swap Clear Pin 47-48 with each other. 47>48 and 48>47

The red wire pin#33 or pin#35 is the Alternator control wire (a must switch)and Pins 47-48 are the downstream O2 sensor signal/low wires.

Step 3
Install 97 Lumina PCM and PCM cover.

Connect battery

Step 4
In HP Editor, change these DTC Codes p1655 and p1671 to (3-no error reported)

These codes are for the Lumina and not for the Grand Prix, as far as I was told. They will signal an SES if not disabled.

YOU ARE FINISHED

It's that easy. I did this myself and it works just as it should. The 1997 Lumina is supported by HPT. My car runs great and throws no errors.

I assume no responibility for following these instructions. Use at your own risk!

You are done!

Most 1996 Grand Prix will need the wire swaps as that is the correct wiring for that yr/model. Though, mine were already swapped so you may get lucky.

Either way, it isn't too hard. I personally did this and it worked