OBD2 GM PCM swap question

How would one select a used replacement PCM for a 2002 Chevy Impala v6 to try? A friend says the current PCM has codes stored that can't be cleared even when power removed. The security light flashes occasionally, vehicle sometimes starts and shuts down (VATS?), so he would like to plug in another PCM to see if it makes a difference.

Obviously the same pcm part number and engine size is a must...just not sure how VATS plays into this year swap. If a swap corrects the problems..a VIN change would be done.

Thanks

Can you post the codes.

I bet the PCM is ok. BCM is what makes problem on this cars.

If you want to try different PCM, unless it is programmed with the correct VIN CAL ID, engine won`t start.
The best thing to do is turn vats off.
It can be done with Tunercat software.
I can give you list with parameters you need to change If you go that route.

look at the service number on the back of the ecm. I have a couple of the era v6 ecm's laying around

Quote:

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Originally Posted by roughneck427

look at the service number on the back of the ecm. I have a couple of the era v6 ecm's laying around

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Asked my buddy to get the PCM number...Thanks..

Quote:

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Originally Posted by kur4o

Can you post the codes.

I bet the PCM is ok. BCM is what makes problem on this cars.

If you want to try different PCM, unless it is programmed with the correct VIN CAL ID, engine won`t start.
The best thing to do is turn vats off.
It can be done with Tunercat software.
I can give you list with parameters you need to change If you go that route.

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What he indicates is that after clearing the PCM (via battery disconnect), he immediately reads the pcm without attempting to start the car, there are no codes, but the IM readiness indicates that EVAP and CATALYST are Not Ready. The remainder of IM tests show "ready" ??? Car starts and runs (most of the time)..but won't pass the plug in NY inspection because the evap/catalyst show not ready.

This is a weird one...

BTW: I can use TunerCat on the OBD2 pcm?

http://www.aa1car.com/library/obd_monitor_not_ready.htm

There is some general information about ready tests perform by Pcm.
Vehicle needs to be driven at specific speed and condition for this test to show ready.
I might try to see whats in service manual about this tests.

Tunercat support most OBD2 GM but you need some special hardware.

Quote:

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Originally Posted by kur4o

http://www.aa1car.com/library/obd_monitor_not_ready.htm

There is some general information about ready tests perform by Pcm.
Vehicle needs to be driven at specific speed and condition for this test to show ready.
I might try to see whats in service manual about this tests.

Tunercat support most OBD2 GM but you need some special hardware.

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Thanks..we are tuned in to the GM drive cycles which aren't responding over the last couple of weeks. The PCM can't just be cleared to begin with.

I'll look in the Tunercat - only because that's interesting!