the PCM is the one that came with the motor/trans., from an 02 camaro. it has a Nelson tune. funny thing is the check engine light, LED on the Nelson harness, doesn't come on either. i unplug the MAF to see if it would throw a code & no light, but when we plugged in the code reader there was a code for the MAF. not sure if that would be in the harness or ECU/PCM.