Service Trailer Brake System

[Jason Stephenson]

I bought a 2014 GMC Sierra new off the lot. Within months of having it I got a Service Trailer Brake System alarm intermittently and it wouldn’t stay constant. I brought it to the dealership and they couldn’t do any troubleshooting without an alarm code, same as with the power steering issue. Over the years the alarm has become more persistent. My trailer brakes and lights have never had any issue and all the connections and cable runs look good. Any advice on here to stop the alarm? Any help is much appreciated.

[wforrest08]

Common problem on these trucks my 015 does it on occasion with or without a trailer hooked up. On mine if I cycle the slide lever on the brake controller it will go away so I haven’t messed with it yet but I’m sure I’ll have to sometime. I did some research on here to find the cause and found all kinds of possible “fixes” in the 20 plus threads. Some guys have found that swapping one of the “control modules” (not sure what it’s really called) above the spare tire fixed it others say swapping the controller worked for them and some say it’s in the wiring/pin fit of the connectors. 
 

The search function on this site SUCKS IMO but if you type this into your google search 

2015 silverado trailer brake warning site:www.gm-trucks.com 

you’ll find most of the threads on here. Lots of good info in them already.

 

GOOD LUCK. 

[swathdiver]

I have the previous generation but have no alarm but a warning message when things with it were not right.  Anytime that message appeared on the DIC there was a trouble code stored in the Chassis Module.  Basic code reader is not going to see it.  There's but three parts to these things, the controls on the dash, the SSR relay and ITBC Module.  Well, the wiring too.  Dirty wires can set off codes.  In my case, it was the SSR that needed changing.  It first started acting up soon after crossing a deep stream.

[Jason Stephenson]

On 11/26/2019 at 11:28 AM, wforrest08 said:

Common problem on these trucks my 015 does it on occasion with or without a trailer hooked up. On mine if I cycle the slide lever on the brake controller it will go away so I haven’t messed with it yet but I’m sure I’ll have to sometime. I did some research on here to find the cause and found all kinds of possible “fixes” in the 20 plus threads. Some guys have found that swapping one of the “control modules” (not sure what it’s really called) above the spare tire fixed it others say swapping the controller worked for them and some say it’s in the wiring/pin fit of the connectors. 
 

The search function on this site SUCKS IMO but if you type this into your google search 

2015 silverado trailer brake warning site:www.gm-trucks.com 

you’ll find most of the threads on here. Lots of good info in them already.

 

GOOD LUCK. 

I appreciate the reply on this. I’m going to look at these things. Thanks.

[Jason Stephenson]

On 11/26/2019 at 12:54 PM, swathdiver said:

I have the previous generation but have no alarm but a warning message when things with it were not right.  Anytime that message appeared on the DIC there was a trouble code stored in the Chassis Module.  Basic code reader is not going to see it.  There's but three parts to these things, the controls on the dash, the SSR relay and ITBC Module.  Well, the wiring too.  Dirty wires can set off codes.  In my case, it was the SSR that needed changing.  It first started acting up soon after crossing a deep stream.

I appreciate the reply. Haven’t dove into it yet but will definitely update this thread when I figure it out. Thanks.