Brake Controller

[Dahillbilly]

Anyone having issue with factory brake controller on 2023 Chevy High Country 3500HD Duramax? Have brake lights on trailer but no brake activation. The electric over hydraulic disc brake system os OK. Thanks

 

[travelin2]

Use the search engine…”GMC Brake controller”. Be a number of posts on this topic

I can’t help you beyond that. I have a ford

 

[cookie]

There is a fuse under the hood for the brake controller.
I think.

Peace
Dave

 

[Dahillbilly]

There is a fuse under the hood for the brake controller.
I think.

Peace
Dave

Dave you are correct this model has two & both are good. From what I'm finding is the brake lights are one source & actual braking is different source & they are tied together somehow!! Enjoy life

 

[xxmxracerxx]

On the older trucks there was a fuse to install. However, this vehicle has a trailer brake control module. The 2 fuses you had checked are for the brake lighting only. What happens when you move the slider for the brake control? Do they apply the brakes? And also, you can use the trailering app on your infortainment system to do a check. Do you have a check trailer wiring message? The control module is mounted to the frame. Will have to lower spare tire down to access. #1 in pic applied.

 

[xxmxracerxx]

Just noticed you stated you have electric over hydraulic. Trailers with electric over hydraulic brakes and some others will require the B+ circuit to the X88 Trailer Connector for the trailer brakes to function. The X50A Fuse block – Underhood provides B+ to terminal E of the X88 Trailer Connector at all times. Anytime a trailer with battery charging capabilities is connected to the vehicle, the trailer battery will be charged through the trailer battery charge control circuit of the vehicle. 30A F63 on your label.

 

[Dahillbilly]

On the older trucks there was a fuse to install. However, this vehicle has a trailer brake control module. The 2 fuses you had checked are for the brake lighting only. What happens when you move the slider for the brake control? Do they apply the brakes? And also, you can use the trailering app on your infortainment system to do a check. Do you have a check trailer wiring message? The control module is mounted to the frame. Will have to lower spare tire down to access. #1 in pic applied.

slider has no effect on brakes; no error messages on infortainment center, system check says OK. thanks for replying

 

[Dahillbilly]

Just noticed you stated you have electric over hydraulic. Trailers with electric over hydraulic brakes and some others will require the B+ circuit to the X88 Trailer Connector for the trailer brakes to function. The X50A Fuse block – Underhood provides B+ to terminal E of the X88 Trailer Connector at all times. Anytime a trailer with battery charging capabilities is connected to the vehicle, the trailer battery will be charged through the trailer battery charge control circuit of the vehicle. 30A F63 on your label.

will check those in the morning, funny thing is it worked couple of times but nothing on the last hook up

 

[xxmxracerxx]

That is odd. I too have a 21 high country and I never had that issue either. However, my rig is electric braking. Only issue I had since I've owned this truck was the trailer lights would stay on at all times even with truck turned off. Turned out to be my trailer lighting control module. (Helps to work at the dealer sometimes) Do hope that 30A fuse fixes your issue.

 

[david-steph2018]

Dahillbilly, are you sure the brake actuator is working?
Story here, we hooked up in Show Low, Az, check brakes working fine. Went down the road about 10 miles, no brakes. I called Performance Trailer Braking, and they worked me thru troubleshooting. Determined it was a bad actuator, shipped one to us. Installed in about 30 minutes.

 

[Dahillbilly]

Dahillbilly, are you sure the brake actuator is working?
Story here, we hooked up in Show Low, Az, check brakes working fine. Went down the road about 10 miles, no brakes. I called Performance Trailer Braking, and they worked me thru troubleshooting. Determined it was a bad actuator, shipped one to us. Installed in about 30 minutes.

Been emailing Mike at PTB the braking system works when power is applied to the pump or if I pull pin on breakaway box. Just nothing going to it. Mike told me to "keep me in the loop".

 

[Gary521]

The brake lights and brake controller are on separate circuits to the trailer. Perhaps the connection point where the trailer plugs into the tow vehicle is not making a good connection. This has happened to me a couple of times. Like you, I had brake lights but no brakes. I replaced the chord and everything worked for a while. Recently, it happened again so I am trying a connector called an "EZ connector, which is magnetic. Try just connecting the trailer to the truck and seeing ( hearing ) if the actuator is working. You could also put a multimeter on the truck connection point and see if you are getting power there to the brake connection point. Have someone step on the brakes.

 

[Dahillbilly]

The brake lights and brake controller are on separate circuits to the trailer. Perhaps the connection point where the trailer plugs into the tow vehicle is not making a good connection. This has happened to me a couple of times. Like you, I had brake lights but no brakes. I replaced the chord and everything worked for a while. Recently, it happened again so I am trying a connector called an "EZ connector, which is magnetic. Try just connecting the trailer to the truck and seeing ( hearing ) if the actuator is working. You could also put a multimeter on the truck connection point and see if you are getting power there to the brake connection point. Have someone step on the brakes.

using volt meter on truck connection getting less than 1 volt when brakes are applied; once the rain stops today going to check fuse 63 that was sugested to check

 

[travelin2]

“Power to the pump”… was that applied through the 7 pin connector?

Old school farm boy here so bear with me…Make a jumper wire and go from the house battery prong to the brake actuator prong. That should eliminate any issue with the connector and pigtail cord

 

[Dahillbilly]

“Power to the pump”… was that applied through the 7 pin connector?

Old school farm boy here so bear with me…Make a jumper wire and go from the house battery prong to the brake actuator prong. That should eliminate any issue with the connector and pigtail cord

done did that & the controller works fine; thanks for the suggestion

 

[travelin2]

done did that & the controller works fine; thanks for the suggestion

Then I guess the problem lies within the truck. Good Luck