Parking brake and ABS light

Hello, I'm Danny.

The first thing I would do is perform a CAN scan. It will check all the systems on your car including the lights including abs you mentioned that are now coming on the dash. Here is a tutorial showing what is involved with a CAN scan:

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

Once you have this performed get back to us with any code information that was stored in your vehicle's computer and we can then properly diagnose what could be causing the problem. After that we can also provide you with wiring diagrams for ground or wiring issues. Hope this helps and thanks for using 2CarPros.

The CAN scan is good. Where do I go next?

Hello again.

So there were no brake or ABS codes present? Thanks again for using 2CarPros.

Danny-

No.

Hello again.

Yes, it is possible you may have a loose or faulty ground connection causing this issue. Here is a wire testing tutorial for you to view:

https://www.2carpros.com/articles/how-to-check-wiring

I've attached a warning light-instrument cluster wiring diagram below for your GMC. I've cut the picture into 3 pieces so you can view larger. I've also circled in red the 3 major grounds you should inspect. Keep us updated and let us know what you find. Hope this helps and thanks again for using 2CarPros.

I don't see the attachment.

Hello again.

Sorry about that. Here are the 3 pictures of the warning light-instrument cluster. I've circled the 3 main grounds you should check first in red. Make sure they are secure, have proper contact, and are not defective in any way. Let us know what you find and keep us updated if you have ant further issues on this question or you need any other diagrams. Hope this helps and thanks again for using 2CarPros.

Danny-

Talking about the rear corner of right rear window. Is it behind the paneling above the window or under the trim of the foot trim?

Hi,

I noticed you haven't been in contact for a couple days. Has any progress been made? We are interested in knowing.

Joe

Hello again.

Yes, the ground will be located under the interior trim panel and will be located close to the floor area. Hope this helps and let us know if you have any further questions on this issue. Thanks again for using 2CarPros.

Danny-