pcmhacking.net

If it's similar to memcal based commodore it can most likely be done with most good scan tool's so long as you have the security PIN for the vehicle.

Where do you get the security PIN from?

If it's the same as the commodore's it should be on a plastic credit card type thing with original books or you can get it from GM themselves if it's lost & they normally charge nominal fee for it.

This security pin that we are talking about. I don't think it has one. I have pulled the steering apart and can confirm that there is a coil that goes around the keyhole for RFID. But I do not think I would have a PIN for any security features, just the transponder in the keys.

Hey edJob,

That blue thing you put a circle around is the PCM MemCal??? I read that from the .pdf file on this site.

See pic below. Does this chip hold any car key RFID information?

And the whole reason for this exercise is because I must have a faulty ignition circuit somewhere are the coil that goes to cylinder 2+3 has intermittent spark. If I could find out what component controls the spark firing signal I could replace that.

The immobiliser info will not be on the memcal. It will be either like antus suggested internally in the main CPU EEPROM (this is how the Commodore PCMs work so my guess would be its the same being that Delco recycle lots of code and tech for PCMs) or an external EEPROM.

The ignition driver IC will be attached to the heatsink at the top of your picture (either under the plastic piece or that larger driver), can use a multimeter to find which chip if you have the wiring pinouts. Not hard to swap these out if you have de-soldering gear.

VL400, great news. Well my coil has two coils. So two cylinders fire off one coil and the other two cylinders fire off the other coil. One coil has intermittent sparking, one does not. I was guessing that there would be two of the same part numbers that would make finding the ignition circuit easier. But when I looked at my board the FET's were different part numbers.

Well I just opened up the PCM from the wreckers and the two mosfets on the heatsink are the same part numbers. I am going to go get my PCM out of the car again and test the mosfets.

Ok my bad. There are two mosfets there on my board that have the same number on them right at the very top.