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Brake Controller:

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Hi Everyone,


About the Factory installed Chevrolet Brake Controller in my 2021 Silverado 2500HD, Crew Cab, Duramax Diesel, Max Tow Package .....


I was burnishing/breaking in the Brakes on my Travel Trailer (Lippert Axle & Brakes ) following the Instructions in the Lippert Owners Manual and the Brake Controller is not working now. 

I therefore have no Trailer Brakes. 

When I start the engine I get a message in the DIC that says " Service Trailer Brakes".

The Trailer Icon on the Controller just above the - and + buttons should light up in Amber color and does not.

When I pinch the Brake Controller the Slide Gauge in the DIC  between 0 and 100 % does not show the Blue Line that tells how much pressure I am applying.

Any thoughts/comments will be appreciated.

Thank You ....

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I don’t have enough experience with this system to be much help, but I would suggest disconnecting and reconnecting the trailer electrical connector with the truck running if you haven’t already. That might reset something. 

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Another JR,

Thanks for your suggestion. I've tried that to no avail.  

I have an appointment with the Chevrolet Dealership on Monday Dec 20th.  They are going to run a diagnostic check to try and locate the problem. 

Thank you !

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Hi 07HD,

Thanks for replying. No such thing as a silly question. I ask enough of them myself. :)

I checked the fuse (#84) in the engine compartment and it's good. 

I have an appointment at the Chevrolet Dealer and they'll be doing a diagnostics check to hopefully pinpoint the problem.

Thank You !

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  • 2 weeks later...

Any resolution to this problem?  Sure it didn't cause an actual problem with the trailer brakes? (loosened magnet, connection, pinched wire, etc...)  I guess I would have started with trailer with that message.

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Hi Wxman,


Thanks for replying.


2 issues regarding my post:


1st:  The "Service Trailer Brakes" message was a bad 30 amp fuse for the brake controller. It's been replaced.


2nd:  The notice I'm getting now says "Check Trailer Brake Wiring". This message comes on when driving and then switches to a different message that says "Trailer Brakes Connected". The trailer brakes work fine when this is displayed. The messages keep going back & forth between the 2 with no brakes when "Check Trailer Brake Wiring".

Leads me to believe your suggestions ( Loosened magnet, connection, pinched wire, etc) is correct. I contacted Lippert and they have authorized the Dealership to diagnose the problem.


Thank you.



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Glad a fuse solved part of the problem.

I had the exact same symptoms as your #2 description.  Two different trucks with previous trailer.  Problem would be nearly constant back and forth one day and then fine the next.  Intermittent nature made troubleshooting a nightmare.  I was led down the path of trailer plug, truck plug, umbilical cord, .....  Often I thought it was fixed (intermittent) and then the messages come back.

Finally found a shorted wire inside the axle tube (lamp cord kinked) where the brake wires were run from driver side to passenger side.  Fixing that really fixed it.

That shorted wire was completely burnt in two.  Best I could tell in the end, when it would bounce around and short against the axle I would get the Check message and brakes inop.  Really bad part was at the end I don't think I had brakes on passenger side even when Connected message was displayed and controller worked.  The wire would bounce around and no longer be shorted against axle so Check message would go away, but by the time I discovered it the wire was certainly not sending any current to passenger side brakes.

In the beginning of troubleshooting I had checked and did have brakes all around during Connected message.  Evidently the short eventually burned through the wire and I falsely assumed Connected meant everything working and Check meant nothing working.

Long post I know.  I fought with this for 2.5 camping seasons. Wish you better luck than I had.

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Thanks Wxman,


I appreciate your reply. My symptoms are exactly what you experienced. I was talking to Lippert about this and they mentioned a lot of what you just said as possible causes. They gave me a Case Number for Warranty Authorization. They seem like real nice people to deal with. I'll post what the cause was after the dealership looks at it.

Thanks again and Happy New Year to you and yours !




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