Restore Safe Towing with a Hassle-Free Solution
If you’re seeing the dreaded “Service Trailer Brake System” message on your dash, you’re not alone. It’s a common and frustrating issue for hardworking truck owners. This message often points directly to a failing Trailer Brake Control Module (TBCM). Located on the frame, this critical component is exposed to harsh road conditions, leading to internal corrosion and electronic failure over time. The result? Unreliable or completely non-functional trailer brakes—a major safety hazard when you’re hauling a heavy load.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and extra cost out of the repair by pre-programming this module to your truck’s specific Vehicle Identification Number (VIN) before it ships. This means you get a part that communicates perfectly with your truck’s systems right out of the box, restoring full functionality without a mandatory, expensive trip to the dealership. This is the ideal fix for both seasoned mechanics and determined DIYers looking to get their truck back to 100%.
From the Diagnostic Bay
I remember a contractor who brought his 2014 Silverado 2500 into my shop, worried sick about a big job he had the next day. The “Service Trailer Brake” light was on, and he couldn’t get any output to his equipment trailer’s brakes. He was expecting a complex, multi-day wiring repair. I ran a quick diagnostic, pulled a code pointing to the TBCM, and checked the module itself—it was caked in mud and salt residue. Instead of a complicated fix, we swapped in a VIN-programmed module just like this one. The whole job took less than 30 minutes. The relief on his face when the warning light vanished and the trailer brakes tested perfectly was immense. He was back on the road, ready for his job, without the downtime or high cost he feared.
Common Signs of a Failing TBCM
A faulty TBCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that this module is the culprit:
- ✔ Persistent “Service Trailer Brake System” message on the driver information center (DIC).
- ✔ “Trailer Connected” / “Trailer Disconnected” messages cycling on and off.
- ✔ No power output to the trailer brakes, confirmed with a 7-pin tester.
- ✔ The manual trailer brake slide controller is unresponsive.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, such as C0299 or related communication faults.
A Straightforward Guide to Installation
Replacing the TBCM is a job most vehicle owners can handle with basic tools. Because we program the module beforehand, there are no complex electronic steps required on your end.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
- Locate the Module: On most Silverado and Sierra pickups, you’ll find the TBCM mounted to the driver’s side frame rail, typically near the spare tire. For Suburbans and Yukons, it’s often on the driver’s side frame rail, around the middle of the vehicle.
- Disconnect and Remove: Carefully unplug the two electrical connectors. They have locking tabs that need to be depressed. Then, remove the bolts holding the module to the frame.
- Install the New Module: Bolt the new, pre-programmed TBCM into the same location. Ensure it is securely fastened.
- Reconnect: Plug the two electrical connectors firmly into the new module. You should hear a click as they lock into place.
- Final Step: Reconnect the negative battery terminal. Start the truck and verify that the “Service Trailer Brake System” message is gone.
Verified Vehicle Compatibility
This module is a direct-fit replacement for the following GM vehicles equipped with the integrated towing package. It is compatible with part numbers 20850923 and 20964299.
- ✔ 2013-2014 Chevrolet Silverado 2500/3500 Pickup (Towing Control; LH rear frame)
- ✔ 2013-2014 GMC Sierra 2500/3500 Pickup (Towing Control; LH rear frame)
- ✔ 2013-2014 GMC Sierra Denali 2500/3500 (Towing Control; LH rear frame)
- ✔ 2013 Chevrolet Suburban 2500 (Towing Control; LH middle of frame)
- ✔ 2013 GMC Yukon XL 2500 (Towing Control; LH middle of frame)
Do I need a dealer to program this 2013-2014 Silverado 3500 TBCM?
Do I need a dealer to program this 2013-2014 Silverado 3500 TBCM?
No. The main benefit of our service is that we program the module to your truck’s VIN before we ship it. This makes the installation a simple plug-and-play process, saving you the time and expense of a dealership visit.
How do I provide my VIN for programming?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship the module until we receive this information, as the programming is essential for it to function correctly in your vehicle.
Will this fix the “Service Trailer Brake System” warning?
In the vast majority of cases, yes. This warning message is the most common symptom of a failed TBCM. Replacing the faulty original module with this pre-programmed unit is the standard, reliable repair for this issue.
Where is the TBCM located on my truck?
For 2013-2014 Silverado and Sierra pickups, it is mounted on the left-hand (driver’s side) frame rail, towards the rear of the truck. On 2013 Suburban 2500 and Yukon XL 2500 models, it is typically found on the left-hand frame rail near the middle of the vehicle.
Is this part compatible with part number 20964299?
Yes, this module, part number 20850923, is a fully compatible and interchangeable replacement for part number 20964299. It will function identically once programmed to your VIN.