Service Trailer Dash Light

[Rudy1]

2016 LML just started throwing the Service Trailer Brake Light On dash.
The only thing is I havnt pulled a trailer yet. Anyways any ideas what I
Should check besides pulling a battery cable. Thanks

 

[Washingtonlmmm]

Ya I’m curious about this too My light comes on everynow and then goes away as soon as truck is off. But my abs light also comes on. Does yours?

 

[trashygasman]

They do this sometimes when it gets wet inside the connector.

 

[NC-smokinlmm]

^ yep...

Why the 2500 diesel if you don't pull trailers?

 

[TheBac]

^ yep...

Why the 2500 diesel if you don't pull trailers?

That matters on this site? :hehe:

 

[Hoser]

^ yep...

Why the 2500 diesel if you don't pull trailers?

This.

 

[NC-smokinlmm]

That matters on this site? :hehe:

Touché...:hug:

 

[scramHD]

Ya I’m curious about this too My light comes on everynow and then goes away as soon as truck is off. But my abs light also comes on. Does yours?[/QUOTE

Loose or dirty ground. Look under driver door, on frame. I believe this is an ABS control module ground. Start there.

There will also be codes to pull from the ecm/tcm. If one relates to the abs control module then this is likely the issue. If either rear tail light blinks after locking the doors with remote, and I mean one side will blink for 15 minutes after door locking, then this particular ground is the issue. Can also check resistance from module I believe also there are more grounds than this one for the abs c/m. The back up camera display lines will freeze also.

Whatever you do, if you have tuning, do not change/modify the tune while this issue is present, youre ecm will lock and youll have a no start condition with mismatching ecm and tune vin.

 

[Rudy1]

Ya I’m curious about this too My light comes on everynow and then goes away as soon as truck is off. But my abs light also comes on. Does yours?

No I have not had the abs light yet. Just that trailer break light.
Comes on like once a week

 

[Rudy1]

^ yep...

Why the 2500 diesel if you don't pull trailers?

I pull a trailer sometimes. Plus I have a Semi too. I like having the 2500hd.
I get good mileage with it too. But I don’t probably need! But it comes
In handy when I do.

 

[Rudy1]

Ya I’m curious about this too My light comes on everynow and then goes away as soon as truck is off. But my abs light also comes on. Does yours?[/QUOTE

Loose or dirty ground. Look under driver door, on frame. I believe this is an ABS control module ground. Start there.

There will also be codes to pull from the ecm/tcm. If one relates to the abs control module then this is likely the issue. If either rear tail light blinks after locking the doors with remote, and I mean one side will blink for 15 minutes after door locking, then this particular ground is the issue. Can also check resistance from module I believe also there are more grounds than this one for the abs c/m. The back up camera display lines will freeze also.

Whatever you do, if you have tuning, do not change/modify the tune while this issue is present, youre ecm will lock and youll have a no start condition with mismatching ecm and tune vin.

. Thanks