Restore Full Electrical Control to Your GM Truck
Are you battling a storm of electrical problems in your 2007-2011 GMC Sierra 3500? From flickering lights and a dead HVAC system to phantom security alerts that leave you stranded, a failing Body Control Module (BCM) can turn your reliable workhorse into a source of constant frustration. The BCM is the central command for your truck’s body electronics, and when it fails, chaos ensues. This replacement module, part number 15943678, is the definitive solution, offered with our expert cloning service to get you back on the road without a costly trip to the dealership.
We transfer the critical data from your original module to this replacement unit. This means the new BCM arrives at your door ready for a true plug-and-play installation, perfectly matched to your vehicle’s specific configuration. Forget about programming fees or complex setup procedures; this is the most direct path to restoring your truck’s functionality and peace of mind.
A Technician’s Notebook: The Grounding Gremlin
I had a 2008 Silverado 2500 in the bay last month with all the classic signs of a bad BCM—intermittent wipers, door locks with a mind of their own, and a persistent airbag light. The customer had already replaced the BCM once himself, but the problems returned within a week. Before condemning the second module, I checked the main BCM ground point (G218) located on the driver’s side A-pillar. Sure enough, it was corroded from years of moisture exposure. After cleaning the contact point to bare metal, all the electrical issues vanished. This is why I always tell my customers: when you replace a 2007-2011 Sierra 3500 BCM, always inspect the ground connections. A 5-minute check can save you from a world of headaches.
Is Your Sierra’s BCM Failing?
A faulty BCM can manifest in numerous ways, often mimicking other component failures. Here are the most common symptoms I’ve seen in my 20+ years of diagnostics:
- ✔ The A/C and heater controls stop working, or the blower motor runs intermittently.
- ✔ Your power windows, door locks, or interior/exterior lights behave erratically or fail completely.
- ✔ An airbag warning light is illuminated on the dash, often with a DTC like B1001 (Setup SDM Primary Key Mismatch).
- ✔ The vehicle’s security system acts up, preventing the engine from starting or causing random stalling.
- ✔ You notice strange electrical behavior, like the radio turning on and off by itself or wipers activating randomly.
A Straightforward Guide to BCM Installation
This is a job most DIYers can handle in their own driveway in under 15 minutes. The BCM is typically located under the driver’s side dashboard, near the steering column.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before working on any electrical components.
- Locate the BCM: On most GM trucks of this era, you’ll find it mounted to a bracket under the dash, to the left of the steering column. You may need to remove a lower dash panel for access.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be depressed. Once disconnected, unbolt or unclip the old module from its mounting bracket.
- Install the New Module: Seat the new, cloned BCM into the bracket and securely plug in all the connectors. You should hear a ‘click’ as they lock into place.
- Reconnect and Test: Reconnect the negative battery terminal. Turn the key to the ‘On’ position and test all body functions—lights, locks, windows, wipers, and HVAC—to confirm the repair was successful.
Post-Installation Note: In some cases, particularly if you had an airbag light, a ‘Setup SDM Primary Key in BCM’ procedure may be required using a bi-directional scan tool. A ‘Brake Pedal Position Relearn’ might also be necessary. Please consult your service manual for model-specific requirements.
Will This Fit My GM Truck or SUV?
This BCM is a direct replacement for part number 15943678 and is interchangeable with a wide range of other GM part numbers. It is confirmed to fit the following vehicles, but always verify your original part number for a perfect match.
SIERRA 3500 PICKUP 08-11 Body Control (BCM); (under steering column)
AVALANCHE 1500 07-11
ESCALADE & ESV/EXT 07-11
SILVERADO 1500/2500/3500 PICKUP 07-11
SUBURBAN 1500/2500 07-11
TAHOE 07-11
SIERRA 1500/2500 PICKUP 07-11
SIERRA DENALI 07-11
YUKON & YUKON XL 07-11
This module is a reliable fix for your 2007-2011 Sierra 3500 BCM and many other GM models, restoring factory performance and dependability.
Frequently Asked Questions
Frequently Asked Questions
What exactly is a ‘Cloning Service’?
Cloning is the process where we transfer the essential vehicle-specific data—like the VIN, security information, and optional features—from your original BCM directly onto the replacement unit. This makes the new module a perfect electronic match for your truck, eliminating the need for dealership programming.
Do I need to send my old BCM to you?
Yes. For the cloning service to work, we need your original module to extract the data. We perform the service and ship both your original module and the newly programmed replacement back to you.
What tools do I need for installation?
For most installations, you’ll only need basic hand tools, such as a socket set or a screwdriver, to remove the lower dash panel and unbolt the module. No special electronic tools are required for the physical swap.
My airbag light is on. Will this fix it?
This module will resolve BCM-related airbag faults, like DTC B1001. However, after installation, you may need a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ procedure to sync the new BCM with the airbag system and turn off the light.
Is there a core charge for this part?
No. We do not require a core deposit. Your original module is used for the data transfer and is always returned to you along with the replacement part.