Electrical Gremlin

[Kurt MacIntosh]

Need some help.

My 07 Yukon has multiple warning lights and warning messages. It has intermittent gauges and it seems to be even effecting the rear suspension compressor.

I was able to pull some codes last night which were pointing to loss of connection to the TCM, but tonight it won't even pull those.

I have cleaned all the grounds and don't want to just start changing modules without some direction.

Any ideas?

 

[Kraig]

I’d start with the Big 3 upgrade to the grounds.

 

[Mickey_7106]

You probably have a bad connection somewhere. I remember on my C5 i would loose connection to the BCM. Turned out it was a wire that was coming loose from its plug in the passenger door wire conduit.

Need some help.

My 07 Yukon has multiple warning lights and warning messages. It has intermittent gauges and it seems to be even effecting the rear suspension compressor.

I was able to pull some codes last night which were pointing to loss of connection to the TCM, but tonight it won't even pull those.

I have cleaned all the grounds and don't want to just start changing modules without some direction.

Any ideas?

 

[Kurt MacIntosh]

I’d start with the Big 3 upgrade to the grounds.

Thank you. What is the Big 3 upgrade? I cleaned the contacts on the grounds under the hood.

 

[Kurt MacIntosh]

You probably have a bad connection somewhere. I remember on my C5 i would loose connection to the BCM. Turned out it was a wire that was coming loose from its plug in the passenger door wire conduit.

Thank you. How many different modules are there and where are they located. The only one that I have located is the one under the dash left of the steering wheel. I removed and reseated that plug. I removed and reseated the one at the TCM, but not the ECM. Its a pretty strange problem and I thinking along the lines of you are saying. Just haven't been able to find info on the BCM locations if there are multiple.

Do you know where I could get a copy of the wiring diagram?

 

[Mickey_7106]

i have no idea, I'm pretty new to this vehicle too

Thank you. How many different modules are there and where are they located. The only one that I have located is the one under the dash left of the steering wheel. I removed and reseated that plug. I removed and reseated the one at the TCM, but not the ECM. Its a pretty strange problem and I thinking along the lines of you are saying. Just haven't been able to find info on the BCM locations if there are multiple.

Do you know where I could get a copy of the wiring diagram?

 

[Kraig]

Big 3 adds ground cables in the engine compartment to ensure you don’t have grounding issues. These trucks do all sorts of weird stuff when the grounds aren’t 100% and adding a few cables is cheap insurance against those problems

 

[Kurt MacIntosh]

Thank you. I'm going to try that and go through the harness from end to end to ensure nothing is loose.

 

[Doubeleive]

another thing you can check is pull the fuse box off and check for corrosion on the contacts

 

[Kurt MacIntosh]

I want to update that I found the problem. It ended up being the suspension control module located above the spare tire. It must be a bad short within the module. I did try everything that was recommended and went through all connections 1 by 1. This module is very expensive. To the tune of 850can.

Any suggestions on a spot to order a new one or a good spot to score a used one?