Mechanics

ELETRICAL ISSUES

1999 Chevrolet Tahoe • 207,000 miles

My truck would just shut off. No check engine light, however the dashboard light come on dim, both turn signal is lit solid and high beam light is lit. When I do turn on my lights, all lights on the dash turns off, but the chime still work. Cranks normal, wont start. I plugged in a lower end OB2 scanner to see if it would give me something. Ironically, as soon as I plug it in, the dashboard goes to normal, truck starts up like its brand new, drive fine with the scanner still plugged in; unplug problem resurface. If u put a high end scanner(the 7-9 grand), the prob is still there, but the device reads no connection. After I took it home, I unplug the ICM, I hear all the modules cycle, like a reset. Plug it back in and I have a brand new truck (for 24 hrs it seems like). I did replace the ICM. It works well for 2-3 weeks, now the problem is back. Any ideas before I start throwing away money.
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G_Smooth1
April 16, 2012.



Oh a few shops I went to, the mechanics first words were WTF

Tiny
G_Smooth1
Apr 16, 2012.
What happens if you try old ICM again?

Tiny
Fixitmr
Apr 16, 2012.
Or did you have to trade it in? Did you get new or used?

Tiny
Fixitmr
Apr 16, 2012.
Does plugging low end scanner with new ICM work too?

Tiny
Fixitmr
Apr 16, 2012.
I replace the ICM out of process of elimination. I had replaced that when I had initially bought the truck. It was still under warranty so I trade it at no cost. It did work for like 3 weeks without an issue. With the new ICM, yes the problem is the same today.

Tiny
G_Smooth1
Apr 16, 2012.
What was the time period between replacements? Was original cause for purchasing the same?

Tiny
Fixitmr
Apr 16, 2012.
The original one was purchased about a year ago. The original was part of a major tune-up I did. (Originally I replaced distributor, cap-n-rotor, TPS, MASS air flow, etc

Tiny
G_Smooth1
Apr 16, 2012.
Ok so dont sound like that part is cause. What about wiring/plug issue? That yr is also known for cluster issues.

Tiny
Fixitmr
Apr 16, 2012.
Maybe a ground connection somewhere?

Tiny
Fixitmr
Apr 16, 2012.
Would a bad ground cause the dash to act the way it is currently?

Tiny
G_Smooth1
Apr 16, 2012.
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