PCM was only $120 including shipping on Ebay.

I needed to change the other parts due to age of car anyway.....

Hopefully this will fix it

 

Still NG!

Put in a rebuilt alternator from Rockauto.com yesterday, also put in a new battery.

Still have P0122 low TPS voltage and still have pulsating electrical system and SES light.

When I turn on the dome lights they pulse too.

If I turn on headlights and then highbeams, and dome lights then put on rear defroster I get a battery light!

Turn everything off and battery light goes off in about 20 seconds.

I think I'll surrender to the dealer's $4,500 computer, maybe threy can fix it.

And changing the alternator was one Royal PITA!

Took me about 6 hours, and I have a lift!

I've got both service manuals and now this has gotten a little out of hand...checked for another voltage regulator, but it seeems like the PCM does that and that's been changed too.

Totally stumped on this one!

 

Sounds like a bad regulator ... did you ever get it checked /tested ??? sounds like the regulator is bad , not in the alternator

 

The PCM modulates the field in the alternator which acts as a voltage regulator....that is what shows in the service manual volume 2 circuit diagram. I changed the PCM also, so there is no other component to replace. There is probably a bad ground somewhere...

 

I'm saying "take it to autozone advanced ect " they do a free charging system check ...
Your rebuilt unit could be bad ... better then spending hours checking wiring for a part that was bad from the start

 

Autozone? Why would I want to take it to them?

So I checked for loose grounds....

Turns out the main grounding cable on the driver side of the engine was totally loose!

Had to tighten the 12MM socket head bolt 2 turns just to get it snug.

Restarted the car and it ran perfectly!

Shut it off, hooked up my code scanner, deleted all codes, resterted and took it for a test drive....no more codes and it purs like a tiger!

All repaired

Thanks for your help though

Everyone should learn from this that checking grounds is an essential part of diagnosing an electrical problem....I learned my lesson

 

omg... yes that makes me want to recheck all of my grounding on my avenger.... i am pretty much following this thread because i am word for word in the exact same boat as you symptom wise... rough idle, flashing lights, occasional can trying to kill itself.

 

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