electrical issue?

2001 CHEVROLET SILVERADO
220,000 MILES • 6.0L • V8 • 4WD • AUTOMATIC
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SCOPLIN
  • MEMBER
  • 2 POSTS
The shift light, gas gauge, and running lights all go on and off. The service 4x4 and ABS lights are staying on as well.
Dec 20, 2022 at 4:16 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
Hi,

Do all of these things go on and off at the same time? I ask because I don't see a connection between them. All have different ground locations, which was my first guess, and they receive power from different places.

The AWD and 4wd can be related if there is a faulty wheel speed sensor.

Let me know. Also, let me know if there are other electrical concerns.

Joe
Dec 20, 2022 at 10:53 AM
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SCOPLIN
  • MEMBER
  • 2 POSTS
Just the shift light, gas gauge and running lights go on and off at the same time. the 4x4 service light comes on about 30 seconds after turn the key and the ABS light comes on a little sooner.
Dec 20, 2022 at 11:32 PM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
I think we are dealing with two different issues. The idea that the ABS and service 4wd come on leads me to think there is an issue with one of the wheel speed sensors.

I do, however, have another question. When you say shift lamp, are you referring to the shift indicator lamp which shows the gear you are in?

I just went through the schematics again. I don't see a correlation in the wiring that would cause the things to flicker on and off.

Let me know about the shift lamp. If it is the gear indicator, then we need to look at the transmission range sensor.

Also, you may want to consider having the can-bus scanned for diagnostic trouble codes. CAN stands for controller area network. Basically, the different modules are all tied together via a few wires and communicate with each other. This type of scan will retrieve codes regardless of the module storing them.

Here is a link that explains how it's done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Let me know.

Joe
Dec 21, 2022 at 11:30 AM
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