Restore Safe and Reliable Towing to Your GM Truck
Is the “Service Trailer Brake System” message on your dash causing you stress? Are you dealing with unpredictable or non-existent trailer braking? Don’t let a faulty module compromise your safety or sideline your truck. This genuine GM Trailer Brake Control Module (TBCM) is the definitive, plug-and-play solution to get you back on the road with confidence. We pre-program this module to your truck’s specific VIN using the latest GM factory software, so it arrives ready for a simple installation with no expensive trip to the dealership required.
Common Symptoms & Your Direct-Fit Solution
A failing TBCM can be more than just an annoyance; it’s a critical safety issue. If you’re experiencing any of the following, this module is the solution you need:
- Persistent “Service Trailer Brake System” warning on the instrument cluster.
- Trailer brakes failing to engage when you press the brake pedal.
- Intermittent or jerky trailer brake application.
- The manual trailer brake controller slide is unresponsive.
- Diagnostic Trouble Codes (DTCs) such as C1512, C1522, or U0100 stored in the system.
This GM trailer brake control module 25788981 is engineered to resolve these issues permanently, restoring the seamless integration between your truck and trailer’s braking systems just as the factory intended.
Features & Real-World Benefits
- âś” VIN-Programmed for Your Truck: We flash the module with your vehicle’s VIN and the newest GM software updates before it ships. This ensures perfect communication with your truck’s other computers for flawless operation.
- âś” Eliminates Dealer Visits: Because the programming is done ahead of time, you can perform the installation yourself or have your local mechanic do it, saving you hundreds in dealer labor and programming fees.
- âś” Restored Towing Safety: Regain precise, reliable control over your trailer’s brakes for safer stops and confident handling of heavy loads.
- âś” Direct OEM Replacement: This unit is a direct replacement for part numbers 20850923, 25854535, 25788981, and 25907533, guaranteeing a perfect fit and function.
- âś” Durable Construction: Built to withstand the harsh environment under your truck, this module is sealed against moisture and corrosion for long-lasting performance.
- âś” This unit is backed by our one-year replacement warranty.
Expert Insight: From Downed Workhorse to Road-Ready in 30 Minutes
We recently worked with a contractor whose 2008 Silverado 2500HD was effectively grounded due to a failed TBCM. He was facing a two-week wait at the dealership and was about to lose a major hauling contract. We shipped him this pre-programmed GM trailer brake control module 25788981 overnight. He installed it himself in his company’s parking lot—it’s located on the driver’s side frame rail and secured with just two bolts. He was back on the road and headed to the job site less than an hour after the package arrived. That’s the power of a true plug-and-play solution: minimizing downtime and keeping your business moving.
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
Absolutely not. The main benefit of our service is that we program the module to your truck’s specific VIN before we ship it to you. It arrives ready to be installed, saving you time and money.
How do I provide my vehicle’s VIN?
After you place your order, you can add your 17-digit VIN to the order notes or send it to us in a message. We cannot ship the part until we have your VIN to complete the programming.
Where is this module located on the truck?
The TBCM is typically mounted to the inside of the driver’s side (LH) frame rail, often near the spare tire. It’s usually held in place by two 10mm or 13mm bolts.
Will this fix the “Service Trailer Brake System” message?
Yes, in the vast majority of cases, a faulty TBCM is the direct cause of this warning message on 2007-2009 GM trucks. Replacing it with this pre-programmed unit is the correct and permanent fix.
My old module has a different part number. Will this still work?
Yes. This module is the updated replacement for several older part numbers, including 20850923, 25854535, and 25907533. As long as your truck is listed in the compatibility chart, this is the correct GM trailer brake control module 25788981 for you.