I need info on how to remove the PCM from my'97 C5. I want to send it out to have it changed to a '98 PCM OS so I can have the car dyno tuned. Thanks,
Rsty

 

Just curious how are they going to change the OS? I was under the impression you could only do a whole computer swap. I have a 97 and tuned it with LS1 edit. I m guessing you want to tune with HPtuners. You might have to go to a dealer to get the 98 computer to run in your 97. I would be interested in knowing how you do this I might want to do the same thing.

 

I removed the PCM from my 2000 for programming recently. You remove the liner at the rear of the front passenger wheel well. There's also a filler piece behind the liner that you have to remove. That will give you enough room to get to the PCM. The Throttle Actuator Control module is screwed onto the PCM bracket, and you have to remove the TAC first. You don't need to undo the TAC connectors. Just unscrew it and let it dangle. Now remove the PCM wiring harness connectors. They're held in with screws from the bottom. The PCM is held in by a bracket going across the front. You completely unscrew the front fastener, but you just loosen the rear fastener and let the bracket stay anchored onto the car. The rear fastener is a PITA to get to; you'll have to do it by feel. Once loose, you can position the bracket out of the way and pop the PCM forward and out. Mine was stuck in there pretty good, and I had to give it a good tug to get it out. If I forgot anything, I'm sure you can figure it out once you're there. Just don't completely remove the rear screw on the PCM bracket!

 

Thank you very very much for those step by step instructions on how to remove it and how NOT to remove the rear screws...I'll get to it this coming weekend...BTW how they your PCM turn out after the tuning and who did it for you?
Thanks again
Rsty

 

I got a mail-order tune from Texas Speed and Performance when I changed the cam. The car's an A4, and I wanted to make sure I could drive the car to a local tuner for an LS1Edit tune on the dyno. I wound up doing cam, heads and headers all at the same time, so I'm not sure how good the mail order tune was since it was just for the cam. The car started and ran with no problems, it seemed a little rich, and I drove it to 21st Century Muscle Cars in Dallas for the 'real' tune.

 

Have another pcm bracket on hand..

They ALWAYS break, (cheap plastic) when you pull out the pcm..!!!!
On install of the new bracket, OR if your lucky NOT to break it, spray the 2 sides with a little WD-40...

Trust me on this..

 

I called the guy you suggested and he never has called me back.

What about the other modules?? Are they going to talk OK with a 98 PCM ????


DJ

 

I heard, but not sure, that the pin-outs on the PCM's are different through-out the years.

 

I got feedback that the '97 and '98 are interchangable without any problems. '99 and later will not hookup because of the differance in the pin setup.