Check Trailer Wiring Message

[Bobtyler]

I have a 2024 GMC 2500HD and a 2022 Rockwood fifth wheel. I'm getting a Check Trailer Wiring Message and then it goes to Brakes Connected Message. All lights seem to be working. Brakes stop working until I get Brakes Connected Message.

[Boo29]

I have 2022 GMC Sierra, pulling a 2023 Forest River Flagstaff Micro lite and get the same message, with a the following message "Trailer Brakes Connected". another message on middle screen reads "brake Gain Not Recalled" The previous Brake Gain setting was not recalled due to an error. Be sure to adjust the Brake Gain. New to pulling travel trailer so not sure what to do.

[jhershon]

Anyone get an answer to this? Seems to be GMC issue that’s been going on for years with no fix? Chevy says it’s the trailer, FR says it’s the Chevy ����*♀️

[PhilFromMaine]

Originally Posted by jhershon

Anyone get an answer to this? Seems to be GMC issue that’s been going on for years with no fix? Chevy says it’s the trailer, FR says it’s the Chevy ����*♀️

Chevy may have owned up to it.

https://gmauthority.com/blog/2023/03...-switch-issue/

[jhershon]

Originally Posted by Bobtyler

I have a 2024 GMC 2500HD and a 2022 Rockwood fifth wheel. I'm getting a Check Trailer Wiring Message and then it goes to Brakes Connected Message. All lights seem to be working. Brakes stop working until I get Brakes Connected Message.

Did you get a fix? We are having the manual brake slide switch replaced but from what I’m reading that won’t fix it. We get other dash alerts and alarms about trailer wiring as well. Chevy telling me it’s the LED trailer brake lights are too low voltage for the Chevy to “sense” there’s a trailer connected BS. We have a brand new 2023 Tahoe

[Bob K4TAX]

Originally Posted by jhershon

Did you get a fix? We are having the manual brake slide switch replaced but from what I’m reading that won’t fix it. We get other dash alerts and alarms about trailer wiring as well. Chevy telling me it’s the LED trailer brake lights are too low voltage for the Chevy to “sense” there’s a trailer connected BS. We have a brand new 2023 Tahoe

Our 2011 Chev Silverado with factory tow package recognizes our trailer lights, brakes, and such without issues. All trailer lights are LED. When the 7-pin plug from the trailer is connected to the truck, the message says Trailer Connected.

Make sure all connections in both the male and female 7-pin connectors are clean. Using some electronic contact cleaner may be required. When the connectors are not in use or otherwise stored, make sure that water does not get inside of them. The tow vehicle connector should have a cover and the trailer connector can be hung across the tongue so it is always facing down. But the insects like to build nests and such in the hollow holes where the contacts are located.

Bob

[jhershon]

HI Bob

TY for your reply. Yes connectors and clean both ends and also brand new. This has been a problem since the first connection to tow. I think your TV @ 2011 may not have the Tow/Haul package that is no doubt computer driven and likely to be more fraught with issues. We are having the one Service Bulletin that GMC has coped to re the manual brake slide is recalled. It's my understanding from other GMC forums that this will not fix the issues but we will give it a go.... Trying to find out if anyone has had a problem with the supposed issue with LED lights drawing too little power and thus the tow haul mode not recognizing anything is being towed. Our problem is that when we are NOT in tow/haul mode we still get the dash board alerts LOL> getting old real fast

[Aussieguy]

if you suspect there is too little draw from the LED
add a incandescent bulb into the brake circuit
-----------------------------------------------------------
BUT...

More than likely it is a connection issue...
Brake controllers when connect will send a very small TEST signal (1v or less) to the trailer's brakes

a bad connection or extremely long wiring can cause enough voltage drop for the tiny signal to get lost ..., hence the message at the controller

ensure good connection at 7 pin's brake AND the ground wire onto the frame.


brake controller is also only used for the brake circuit, if other stuff like turn signals work is of no concern...


only look at the 7 pin brake wire + ground (white)... + look for any signs of wire damage all the way to the trailer wheels.

here is a good article on testing the brakes
https://www.etrailer.com/faq-testing...-function.aspx



..

[Bob K4TAX]

Originally Posted by Aussieguy

if you suspect there is too little draw from the LED
add a incandescent bulb into the brake circuit
-----------------------------------------------------------
BUT...

More than likely it is a connection issue...
Brake controllers when connect will send a very small TEST signal (1v or less) to the trailer's brakes

a bad connection or extremely long wiring can cause enough voltage drop for the tiny signal to get lost ..., hence the message at the controller

ensure good connection at 7 pin's brake AND the ground wire onto the frame.


brake controller is also only used for the brake circuit, if other stuff like turn signals work is of no concern...


only look at the 7 pin brake wire + ground (white)... + look for any signs of wire damage all the way to the trailer wheels.

here is a good article on testing the brakes
https://www.etrailer.com/faq-testing...-function.aspx



..

I agree with Aussieguy. The only sense line is the brake system. LED or not, the lamps are not polled by the computer. Only the brake system.

Likely the issue is with with the ground connection on your trailer. I found mine to be poorly made using only one self-drilling screw through the frame. It was loose and rusty. I removed the screw, drilled the hole to 1/4", sanded away the paint on both sides to make good electrical contact, and installed a proper bolt, lock washers, and nut along with a new wire terminal. Brakes greatly improved and random issues disappeared.

Also, the charging current from the truck to the trailer improved to a higher number of amps.

Bob