Jump to content

Need help with factory Brake Controller


Recommended Posts

I have a 2015 GMC Sierra, I don't tow a lot so not much use on my itbc. I got an error of service trailer brake system and even check wiring a time or two. I used to regularly get the warning about the brakes on the dic. It's obvious the trailer brakes aren't working. I'm not knowledgeable in this area. But I did check to see if I'm getting voltage to the terminal for the brakes on the 7 pin connector. I used a test light. All pins work except for the trailer brake terminal, had my girlfriend step on brakes and even tried the brake slider switch above the headlight switches. Nothing. Last two times I hooked up my trailer I did not get any warning and not even a trailer connected message. I did have to replace the left turn signal fuse for the trailer during this mess, and the trailer brake j-fuse is good. I took it to the dealer and they were useless.

I know there's several components to check. Please help guys/gals!

Link to comment
Share on other sites

You won't get any voltage on the brake connector with just a test light. The controller is looking for a load (the magnets) on the circuit before it senses a trailer being connected. So you either have to simulate the load or actually hook a trailer up to it in order for the controller to sense it and apply power to the circuit.

 

Since the controller isn't even recognizing a trailer being connected now, I'd suggest hooking up to a different trailer and seeing if it works on it.

 

If you don't have access to another trailer then I'd suggest having a friend hook their truck the your trailer and see if their controller senses the trailer brakes.

 

If you have one close to you, it would probably be worth taking the truck to a utility trailer place and see if they'll test the controller and maybe even the trailer for you.

Link to comment
Share on other sites

Thank you guys. Good info. I was wondering if it was my trailer, but thought it wasn't due to the fact I thought that pin in the connector always got voltage. I will see if I could use somebody else's truck or trailer to determine if it's my trailer or my truck before I put any time into diagnosing my truck. Using somebody else's truck or trailer is a whole other issue..ugh... lol. Thank you guys.

Link to comment
Share on other sites

Could be brake fluid level, check service bulliten PIT5490. Dealer filled mine to the brim after I was randomly getting error message and no brakes, hadn't had a problem since.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.