When your dashboard displays the Service Trailer Brake System warning message, it
indicates there is a problem with the electrical wiring of your trailer brake controller
or module that prevents electricity from flowing freely through it – this could be
caused by corrosion in connectors or other sources.
This article will demonstrate how to address this problem and get it running again.
Steps include unplugging the brake controller, disconnecting it, and cutting its
output wire from its controller.
Check Brake Lights
Usually when the Service Trailer Bra System message appears it indicates a
controller issue; often due to a module or wiring issue which prevents electricity
from passing through ITBCs. This poses serious safety concerns and it should be
rectified as soon as possible – driving your truck should not proceed until this issue has been addressed.
It is particularly important to regularly inspect your brakes if you use your vehicle for
hauling trailers over long distances, or when towing trailers of any sort. Also check
them at least annually or every 12,000 miles; whichever comes first.
If your brake controller is malfunctioning and no other solutions exist, replacing it
may be your only recourse. Testing it with a volt meter or battery tester is best
practice to make sure everything is functioning as it should be.
Check the Connections
People may encounter the “Service Trailer Brake System” message when something
in their truck or trailer is malfunctioning; this may involve either the brake controller,
wiring issues, or something else entirely. To isolate this problem quickly, remove the
cover from your power junction box as this is often where problems lie.
Check and clean all wiring connections, making sure they are not corroded or
disconnected, before inspecting the interior of your truck. Replace any blown fuses;
there may be multiple fuse boxes in this model vehicle and multiple types of fuses
which should all have locations listed in its owner’s manual.
Additionally, check the brake control switch under the dash for any malfunction or
replacement requirements. While reports might indicate this is indeed the culprit,
other accounts indicate it might not be; there may also be an issue with an undertruck module near the spare tire that needs attention.
Turn Off the Trailer Brakes
When the “Service Trailer Brake System” warning message appears on your
vehicle’s dashboard, it indicates an issue with either its ITBC module or wiring that
must be resolved before driving again. Since ITBCs are powered through your truck’s
electrical system and when encountering difficulties with either its wiring or module
they cannot deliver their signals as required triggering an error code on the dash.
Unplugging the brake controller will reset its system and prevent any future
dashboard notifications of it being present.
If you cannot unplug your controller, cut the brake output wire anywhere between
your trailer and brake controller to release tension in it and drive away without
incident. Also be sure to check any fuses related to trailer functions, such as the RT
or LT fuse or Park lamp Fuse labeled INT PRK 10amp located either underhood fuse
box or instrument panel fuse box.
Reset the Trailer Brakes
Resetting your trailer brakes when the “Service Trailer Brake System” message on
your truck appears isn’t difficult and won’t take too much time; just use some basic
tools like a flathead screwdriver for ease of doing so.
Locate and loosen the adjusting nut on the rear side of the trailer brakes (usually
close to the axle). Use a flathead screwdriver to unbolt its locknut, then turn
clockwise with your flathead screwdriver until the nut turns free of its holding bolt.
Underneath the steering wheel lies a brake control switch which could be failing and
contributing to your “Service Trailer Brake System” message. Replacing it shouldn’t
be too expensive and can help avoid potentially hazardous road situations.
If none of these solutions work, replacing the fuse that controls your trailer brake
controller could be necessary. You can easily purchase this online component and
have it installed quickly and without difficulty.