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Discussion Starter #1
Well, the suburban has been sitting for over a week at the dealers'. they finally got to look at it today. of course, no symptoms. truck ran fine.

symptoms are that it stalls or simply won't start. WTS like doesn't come on and lift pump doesn't get power. Service engine soon light is on, but no codes. before I replaced one of the battery grounds, ses light would flicker and relays would rattle away in the underhood fuse box. AC clutch would engage and disengage with engine off and ac turned off.


I talked to the service guy today. Truck runs fine. He said it might be the ignition switch or the pmd. I told him that I've replaced both already. Then he said possible pcm. He commented that perhaps vehicle shifted funny lately as another possible symptom (it actually has been throwing some weird shifts).

Has anybody had a pcm failure or know possible symptoms? This stalling problem is beyond the pmd cure all.:cool:
 

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I had electrical short in wiring just outside firewall between computer and IP.

I replaced ECM (twice), IP (twice), CPS, PMD (twice), electrical grounds were all replaced, I took it to 2 diesel shops, and 2 dealers and they couldn't find the problem.

I would do a manual check of all grounds, and each wire from ECM to IP. Make sure you take the looms and wraps off. Good luck.
 

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I would do a manual check of all grounds, and each wire from ECM to IP. Make sure you take the looms and wraps off. Good luck.
I'd be checking the grounds too. Electricity can do some really weird stuff when it's not grounded properly.
 

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I picked up the suburban tonight. I spent about an hour talking to the tech who worked on it. Really nice guy. He was apologizing for not pinpointing the problem. He said 99% sure that it's the pcm. New pcm ordered and on the way from Westers (life time warranty:D ).

He also said grounds look pretty good, but to replace terminal ends on grounds from pcm just to be safe. He brought out the shop manual and went over which wires to test. He even offered to lend it to me.

Since the stalling problem has been sensitive to temp and humidity, I'm going to remove the pcm and put it in the deep freezer for a couple hours. I'm hoping that will trigger the stalling problem and give me closure on this problem.

Aside from that, the tech was very impressed with my truck. Nothing but compliments, solid truck, can't believe it's a ten year old truck, motor has all the guts in the world and so forth. It was nice to hear, especially after the bad run of luck I've been having with it.
 
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