No communication?

BRANDON WATSON

MEMBER
2008 GMC YUKON
5.3L
V8
4WD
AUTOMATIC
220,000 MILES

I have had an intermittent problem with my vehicle losing communication. No crank no start door unlocking and locking and so on. I was at work, and it would not do anything. I unplugged battery nothing disconnected ECM nothing TCM nothing but when I disconnected ABS module it fired right up. Not sure what's the main problem?

Friday, August 25th, 2023 AT 6:06 PM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

It sounds like the PCM, BCM or ABS module is shorting out, but we need to do a CAN scan to see what codes are stored.

You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

Here is how to change out the BCM in case a code comes up for it, you can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

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Saturday, August 26th, 2023 AT 12:55 PM

BRANDON WATSON

MEMBER
2 POSTS

I have the U0073 code control module communication bus a off.

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Saturday, August 26th, 2023 AT 1:03 PM

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

The U0073 code is a generic diagnostic trouble code (DTC) that indicates a communication problem between different control modules in the vehicle. I would turn the ignition on and check all fuses, this guide can help:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the images (below). Please let us know what happens. It still sounds like the BCM is out.

Images (Click to make bigger)