3.1 PROM/MEMCAL

[Nexum]

Hey guys. I've got a '90 Pontiac 6000 that's been acting up lately. A trouble code check tells me that it's the ECM/PROM. I know where the ECM is and how to remove it, but how do I know if I need to replace the whole module or just the chip? I've thought about just grabbing a new PROM, but aside from local salvage yards(last resort) I don't know where to find one. Can anyone help me out as to finding a new PROM or ECM? Any info would be greatly appreciated.

[SappySE107]

You would just need to replace the entire memcal, which is simple. A new memcal from GM is about 70 bucks....insane. Finding the memcal you need in the junkyard is probably gonna be hard unless you know where another car like yours (same year, engine, trans) is sitting.

What is the 4 letter code on your stock memcal? That will tell you which chip you need if it is the memcal that is your problem. Most of the time it is the ECM and not the memcal that goes bad if either are to blame. The computer itself should be easier to find because it was used in a lot of cars. Im not sure where yours is located, but if its inside the car, then you can find one from an 88-94 J body, 88-93 L body, or another A body. Pretty common computer.

[Cliff8928]

I bought a new Cal-Pak from GM and it was only like $40? from GMPartsdirect. Every one i looked for in the Junkyard had it gone.

Cliff Scott
89 BerettaGT
89 Volvo740