Could this be a VATs issue?

I think that if it were a VATS issue the security light would be on

One other huge thing I forgot to mention.

Your pcm is not the cause of bad gauges. The oil pressure reading does not travel through the pcm at all. Volts probably doesn't either. I would think the cluster is bad or there is a bad ground etc causing the issue.

The start and stall out condition is classic VAT'*, I'm thinking your security light, never flashes or lights? That would mean the bulb is burnt out. It should flash at some point just to show us it'* working.

My suggestion is to put the original PCM back in and verify the car starts and runs. Then give us a little more info about when each gauge stopped working properly and their symptoms. We should then be able to help you diagnose a cluster, ground or sending units.

When you turn the key all dash lights should come on to show they are working. If no security light at that time, then it'* burnt out.

BillBoost37, I tend to agree with you but I already replaced the cluster and I have cleaned both buss bar grounds, cleaned all fender grounds, cleaned all battery cables, replaced the alternator, and replaced the pressure sender. I'm kind of at a loss now, I swear that I saw that the PCM feeds the oil pressure gauge on a diagram, I'm going to look for that again.

If so...and I've been mistake before (in pre 2000 the pcm wouldn't actually do anything with that info if it'* getting it.) and if I am...I'm out for a different pcm to fix my oil and alt issues in my car.

I say try this. https://www.gmforum.com/electrical-133/bypass-vats-92-99-a-279119/ The way the write up is done you can put it right back if it didn't work.

Like mentioned, I am having trouble understanding the desire to to bypass the VAT'*, it'* not part of the issue.





OP and volts are direct.

your problem is not security related
The PASS-Key II ® module produces the Theft Deterrent Fuel Enable signal when ignition is ON and the proper key resistor pellet is sensed by the PASS-Key II ® module. The PCM monitors the Fuel Enable signal during crank. If the proper signal is present on the Theft Deterrent Fuel Enable circuit, the PCM enables fuel delivery to allow the engine to start. If the PCM detects that the fuel enable signal is not present or is incorrect while an attempt is made to start the engine, DTC P1629 will be set. The engine will not start as long as this condition is present. If the problem also affects inputs to the PASS-Key II ® module, the starter motor may be disabled. If this condition is present, refer to Theft Deterrent Systems for further diagnosis.

Different years handle the pass key in different ways. Some years wont crank. Others allow the fuel pump to prime, the engine will crank, fire, then die because the injectors shut down.