Restore Full Functionality to Your GM Truck
Are you battling a frustrating array of electrical issues in your GMC Sierra, Chevy Silverado, or another GM truck/SUV? Flickering lights, a dead HVAC blower, or power windows with a mind of their own are often symptoms of a failing Body Control Module (BCM). As the central command for your vehicle’s body electronics, a faulty BCM can cause chaos. This replacement BCM, part number 15943678, is the definitive solution, offered with our expert cloning service to make your repair simple and permanent.
We transfer the exact data from your original module to this replacement unit. This means the module arrives at your door ready for a true plug-and-play installation, perfectly matched to your vehicle’s VIN and options. You get to skip the expensive and time-consuming trip to the dealership for programming—a huge win for both professional shops and DIY mechanics.
Is Your Truck Showing These Symptoms?
- ✔ The air conditioning or heater blower motor works intermittently or not at all.
- ✔ Your airbag warning light is illuminated, often with a diagnostic trouble code like B1001.
- ✔ Power door locks, windows, or exterior lights are malfunctioning or unresponsive.
- ✔ The security system acts up, potentially causing no-start or stalling conditions.
- ✔ You’re seeing a variety of seemingly unrelated electrical trouble codes on your scan tool.
- ✔ Poor ground connections at the BCM are causing erratic behavior across multiple systems.
A Technician’s Notebook: The Case of the Haunted Sierra
I once had a 2013 Sierra 3500 in my bay that was driving the owner crazy. The radio would change stations on its own, the dome light would flicker, and occasionally the truck wouldn’t start. He had already replaced the battery and checked the alternator. After hooking up my scanner, I saw a dozen communication codes pointing in different directions. From experience, I know these ‘haunted’ electrical problems often lead back to one of two things: a bad ground or a failing BCM. I checked the main BCM ground under the dash—it was clean and tight. That left the module itself. We sent his original BCM for our cloning service, and the replacement part fixed every single issue. It’s a reminder that the BCM is the vehicle’s nerve center, and when it fails, the symptoms can be bizarre and widespread.
A Straightforward Guide to BCM Installation
Replacing the BCM is a quick job that most people can complete in their own driveway. Our cloning service makes it a direct swap.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before working on electrical components.
- Locate the BCM: On most 2007-2013 GM trucks and SUVs, 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, unclip or unbolt the module from its mounting bracket.
- Install the New BCM: Mount the new, cloned BCM in the same location and securely plug in all the electrical connectors. You should hear a ‘click’ as they lock into place.
- Reconnect Power: Reattach the negative battery terminal.
- Post-Installation Checks: Start the vehicle and test all body functions—lights, locks, windows, wipers, and HVAC. If your airbag light is on, you will need a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ function. Some models may also require a Brake Pedal Position Relearn.
Guaranteed Fitment for Your GM HD Truck
This module is a direct replacement for part number 15943678 and is interchangeable with several other part numbers, including 25835966, 15263363, 15878753, 25940214, and more. It is designed for a wide range of GM vehicles. While this is a 2013 Sierra 3500 Body Control Module, it also fits many other models. Please verify your part number or consult the compatibility list below.
Frequently Asked Questions
What exactly is a cloning service?
Our cloning service is a process where we transfer all the critical vehicle-specific data—like the VIN, mileage, and optional equipment settings—from your original BCM to the replacement unit. This ensures the new module is a perfect electronic match for your truck, eliminating the need for dealership programming.
Do I need any special tools for installation?
Basic hand tools like a socket set or screwdriver are usually all that’s needed to access and replace the BCM. However, if the airbag light remains on after installation, a high-level diagnostic scan tool is required to perform the ‘Setup SDM Primary Key’ procedure.
What if my original part number is different?
This module is interchangeable with many GM part numbers. As long as your original part number is on our cross-reference list, this module will function correctly in your vehicle after our cloning service.
Is there a core charge for my old BCM?
No. We require your original module to perform the cloning service, and we always return your original part to you along with the newly programmed replacement. There is no core charge or need to send it back again.
Will this 2013 Sierra 3500 Body Control Module fix my airbag light?
If the BCM is the cause of the airbag light (commonly with code B1001), this replacement will resolve the root problem. However, the airbag system (SDM) and BCM must be electronically synced after installation using a scan tool to turn the light off. This is a required security procedure on all modern vehicles.