1994 Z28 PCM Question???

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Jun 9, 2010 | 08:55 AM

CS Vette

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1994 Z28 PCM Question???

I'm looking for a PCM for my 1994 Z28 to fix my A/C issue. I plan on looking thru a few junk yards this weekend. Is there anything I need to know before pulling one? Are all 1993-1997 PCM's the same? Does it matter if the car is an auto or manual? Should I be concerned about the OBD-1 / OBD-2 situation? Is there a way to identify them (ie: part number/serial number)?

Thanks Fellas!

Jun 9, 2010 | 10:25 AM

Ed Wright

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Quote:

Originally Posted by CS Vette

Only '94 & '95 PCMs are the same. All '94/'95 non-Vet LT1 PCMs are the same. If you don't want to have it programmed with your vin, and for your car you need to find one for a manual trans if that is what you have, or if you have an automatic it needs to have the same gear ratio (2.73 or 3.23). If you are going to have it flashed with the correct vin and calibration, it won't matter about the transmission or gears. A '94/'05 Caprice, Impala SS, Caddy Fleetwoods or Buick Roadmaster box is the same service number and can be programmed for your car also. Just transfer your ESC module if you use a B (Chev) or D (Cad/Buick) body PCM. The '94/'95 4.3L Caprice ("baby LT1") PCM is the same box, and can be reflashed for an F LT1 body also.

Good luck, Ed

Jun 9, 2010 | 03:00 PM

CS Vette

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Staging Lane

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Great info Ed! Sounds like it would be best to seek out a PCM from an automatic 1994/1995. I guess that just leaves one more question: How do I know what rear gears are/were in the junk yard car? Is there a way to decode the VIN or RPO codes in the door?

Thanks again!

Jun 9, 2010 | 03:18 PM

Ed Wright

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Unless they have been changed the 2.73 cars will have the code GU2, the 3.23s will have GU5. Be aware, if you aren't going to flash the PM with your vin and calibration you get the correct year model. A '94 car with a '95 calibration will set a DTC 83 (Pulse Width Modulated TCC Solenoid) and you will have TCC lock up issues. With a '94 car you have to have a '94 calibration. The smart thing would be to have it flashed with your in and the correct calibration. Wouldn't matter wht it came out of in that case. The salvage is likely to have the PCM inside, not out in the car. No way to know for certain which car it came from in that case.

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