Tired of Chasing Electrical Gremlins in Your GM Truck?
If your 2013 GMC Sierra 2500 is acting possessed—with flickering lights, a dead radio, or a climate control system with a mind of its own—you’re likely dealing with a failing Body Control Module (BCM). As the central command for your truck’s body electronics, a faulty BCM can cause a cascade of frustrating and seemingly unrelated problems. From power windows that won’t budge to a security system that prevents your truck from starting, the BCM is often the root cause. This isn’t just an annoyance; it can be a significant safety issue when exterior lights or airbag systems are compromised.
This replacement Body Control Module, part number 20939138, is the definitive solution. We simplify the repair process with our professional Cloning Service. You send us your original module, and we transfer all the critical vehicle-specific data to this replacement unit. The result? A true plug-and-play module that requires no expensive trip to the dealership for programming. It arrives ready to install, restoring full functionality and communication between your truck’s essential systems.
A Technician’s Notebook: The Misleading Airbag Light
A customer brought in a 2011 Silverado 2500 with an airbag light that two other shops couldn’t fix. They had already replaced the clock spring and the passenger presence sensor. The key was the DTC B1001: ‘Option Configuration Error’. This code doesn’t point to a faulty airbag component, but a communication breakdown between the new BCM and the SDM (airbag module). In my shop, I’ve seen this dozens of times. A simple ‘Setup SDM Primary Key’ procedure with a pro-level scan tool after installing the new BCM is all it takes. This highlights why a proper diagnosis and understanding the full system is crucial, and why our pre-cloned modules, combined with the right post-install knowledge, save our customers time and money.
Is Your Truck Showing These Symptoms?
- ✔ The airbag warning light is illuminated, often with a DTC like B1001.
- ✔ Power windows, door locks, or mirrors work intermittently or not at all.
- ✔ HVAC controls are unresponsive, or the blower motor behaves erratically.
- ✔ Interior dome lights or exterior lamps fail to turn on or off correctly.
- ✔ The vehicle’s security system malfunctions, causing no-start conditions or false alarms.
- ✔ You’re experiencing strange electrical issues, like the radio turning off unexpectedly.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your truck’s battery before working on electrical components.
- ✔ Locate the BCM: On most GM trucks from this era, the BCM is located under the driver’s side dashboard, near the steering column. You may need to remove a lower dash panel for access.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old BCM. They have locking tabs that need to be depressed. Once disconnected, unbolt or unclip the module from its mounting bracket.
- ✔ Install the New Module: Seat the new, cloned BCM into the mounting bracket and securely plug in all the electrical connectors. You should hear a click as they lock into place.
- ✔ Post-Install Checks: Reconnect the battery terminal. Start the vehicle and test all body functions: lights, wipers, windows, locks, and HVAC. As noted, if the airbag light is on, a ‘Setup SDM Primary Key’ procedure may be needed.
Verified Vehicle Compatibility
This module is a direct replacement for a wide range of 2007-2013 GM trucks and SUVs. It is interchangeable with part numbers including 25844480, 25835966, 15943678, 20939137, and 22860591. While this is a common part for a 2013 Sierra 2500 Body Control Module, please verify your part number or consult the fitment list below to ensure perfect compatibility.