Codes U1534 and U1538, driver's window switch not working?

Tiny
RONSKI502
  • MEMBER
  • 2019 GMC TERRAIN
  • 1.5L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 77,000 MILES
I have the codes U1534 and U1538. Communication with driver's door. I'm looking for LIN wire colors and BCM plug color to trace communication problem. Driver's door switch or the BCM are not the problem. Nor is the programming.
Monday, May 12th, 2025 AT 12:28 PM

1 Reply

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 51,603 POSTS
The first thing to do is turn the systems on and check all fuses, here is a guide to help:

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

U1534 - Lost Communication With Telematics Control Module on LIN Bus
U1538 - Lost Communication With HVAC Control Module on LIN Bus

Since these modules are daisy chained together. the first module in line is usually the problem so the telematics control will be the issue. I would try unplugging it, and then plug it in again. This can sometimes fix it. Also, I would try a hard system reboot.

This guide will show you how:

https://www.2carpros.com/articles/step-by-step-guide-performing-a-hard-system-reboot-for-your-vehicles-electronics-systems

Here is the locations of the Telematics Control Module so you can check it out. Check out the images (below). Please let us know what happens.
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Wednesday, May 14th, 2025 AT 11:10 AM

Please login or register to post a reply.