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2011-2012 Silverado 3500 Trailer Brake Control Module (TBCM) 20791897 – Programmed to Your VIN
Why Is Your Truck Displaying a “Service Trailer Brake System” Warning?
Drivers of 2011-2012 GM HD trucks often ask, “What causes the trailer brake system warning to pop up on my dash?” The answer frequently points to a failing Trailer Brake Control Module (TBCM). From my two decades in diagnostics, Iโve seen this exact issue hundreds of times. The module’s location on the left-hand rear frame rail exposes it to a brutal mix of road salt, water, and debris, leading to the number one cause of failure: corrosion. This corrosion attacks the electrical connector and can even penetrate the module’s housing, shorting out the internal circuit board.
This isn’t just an annoying light; it’s a critical safety failure. A malfunctioning TBCM, part number 20791897, can leave you with no trailer brake output, intermittent brake application, or complete communication loss, putting you and your payload at risk. This pre-programmed module is the definitive solution to restore safe, reliable towing performance to your truck.
A Deeper Look at TBCM Failure and Our Solution
When a TBCM fails, it’s not always a simple on/off issue. You might experience fluctuating gain settings or find the manual override slider is unresponsive. Because this module communicates on the vehicle’s CAN bus network, a faulty TBCM can sometimes trigger seemingly unrelated diagnostic trouble codes (DTCs).
Our solution eliminates guesswork and costly dealership visits. We take a genuine GM module and flash it with the latest, most stable software updates using your vehicle’s VIN. This ensures perfect compatibility and function right out of the box, resolving common issues like:
- ✔ Constant “Service Trailer Brake System” or “Check Trailer Wiring” alerts
- ✔ No power output to the trailer’s electric brakes
- ✔ Inability to adjust brake gain on the dash controller
- ✔ Complete loss of communication with the module (verified with a scan tool)
Expert Pro Tip from the Shop Floor
Before ordering, take a moment to inspect the wiring harness connector that plugs into your old TBCM. I’ve seen cases where a new module fails to fix the problem because the connector pins themselves are corroded or broken. Clean the connector thoroughly with an electrical contact cleaner and check for any green or white crusty buildup. A dab of dielectric grease upon reassembly will provide excellent protection against future moisture damage.
Plug-and-Play Installation: No Dealer Visit Required
Replacing the TBCM on your Silverado or Sierra is a straightforward process. Since we program the module to your VIN before shipping, you won’t need any special scan tools or a trip to the dealership. This saves you significant time and money.
- Safety First: Disconnect the negative battery terminal.
- Locate the Module: Find the TBCM mounted on the driver’s side frame rail, typically near the rear axle on pickups or mid-frame on Suburbans.
- Swap the Part: Disconnect the electrical connector and unbolt the old module. Bolt the new module in its place, securely reconnect the harness, and then reconnect your battery.
- Final Check: Start the truck. The “Service Trailer Brake” message should be gone, and all functions restored. No further relearn procedures are necessary.
Guaranteed Fitment for Your GM Truck or SUV
This module is a direct-fit replacement for several GM heavy-duty vehicles. We guarantee compatibility for the following models equipped with the factory towing package:
- 2011-2012 Chevrolet Silverado 2500/3500 PICKUP (Towing Control; LH rear frame)
- 2011-2012 GMC Sierra 2500/3500 PICKUP (Towing Control; LH rear frame)
- 2011-2012 GMC Sierra Denali 2500/3500 (Towing Control; LH rear frame)
- 2011-2012 Chevrolet Suburban 2500 (Towing Control; LH middle of frame)
- 2011-2012 GMC Yukon XL 2500 (Towing Control; LH middle of frame)
Don’t let a faulty module sideline your work or recreation. Restore your truck’s full towing capability and peace of mind. Simply provide your VIN during checkout, and weโll handle the programming. Get your truck back on the road safely and quickly.
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