Is Your Sierra Denali Experiencing Strange Electrical Problems?
The Body Control Module (BCM) is the central command center for your truck’s body electronics. When it begins to fail in a 2007-2010 GMC Sierra Denali, it can cause a cascade of frustrating and seemingly unrelated issues. From power windows that won’t budge to a security system that acts possessed, a faulty BCM can make your reliable truck feel unpredictable. This isn’t just an inconvenience; it can affect vehicle safety and operation. This genuine GM Body Control Module, part number 25835966, is the definitive solution to restore your truck’s electronic systems to perfect working order.
From the Diagnostic Bay
We had a 2008 Sierra 2500 come in with a classic case of BCM failure that had the owner chasing ghosts for weeks. The radio would turn on and off by itself, the driver’s side power lock was intermittent, and the HVAC blower motor would only work on high. The owner had already replaced the blower motor resistor and the door lock actuator with no success. After a quick scan, we found multiple communication loss codes pointing to the BCM. By installing a VIN-programmed module like this one, we resolved all the issues in under 15 minutes, saving the customer from further expensive and incorrect repairs.
Common Symptoms of a Failing BCM
- ✔ Power windows, door locks, or mirrors operating intermittently or not at all.
- ✔ Interior or exterior lights flickering, staying on, or failing to turn on.
- ✔ HVAC and climate control functions working erratically or not responding.
- ✔ An illuminated airbag warning light, often with diagnostic trouble code (DTC) B1001.
- ✔ Vehicle security system malfunctions, causing no-start conditions or false alarms.
- ✔ Wipers behaving unpredictably or not parking in the correct position.
- ✔ Communication errors with other vehicle modules reported by a diagnostic scanner.
Your Plug-and-Play 2007-2010 Sierra Denali BCM Solution
Don’t let a faulty module keep your truck down. This BCM is the ideal fix, arriving pre-programmed to your vehicle’s specific VIN. This crucial step ensures that all vehicle options and security protocols are correctly configured right out of the box. You get a component that integrates seamlessly with your Sierra’s existing systems, eliminating the need for expensive programming at a dealership. We load the latest GM software updates, which can resolve issues that were present even when your original module was new. It’s a simple, effective way to get your truck back to 100%.
Installation and Post-Install Notes
Installation is straightforward for most DIY mechanics. The BCM is typically located under the driver’s side dashboard, near the steering column. While the physical swap takes only a few minutes, be aware of potential post-installation procedures. If the airbag light remains on, a professional scan tool is needed to perform the ‘Setup SDM Primary Key in BCM’ function. In some cases, a ‘Brake Pedal Position Relearn’ may also be required. Always consult a service manual for your specific vehicle if you are unsure. Best of all, there is no core charge—you can keep your old part.
This module is a direct replacement for part numbers: 25835966, 15263363, 15263497, 15878753, 15284816, 15943678, 15926094, 15940214, 25790508, 25790509, 25823558, 25823559, 25835965, 25844479, 25971916, 25971917, 15901388, 20939137, 20939138, and 22860591.
Frequently Asked Questions
What does the Body Control Module do on a GMC Sierra?
The BCM acts as the brain for your truck’s body electronics. It controls non-engine related functions like power windows, door locks, interior and exterior lighting, the security system, wipers, and HVAC controls.
Is this BCM ready to install right out of the box?
Yes. We pre-program the module to your vehicle’s VIN before shipping. This ensures it is a plug-and-play installation with no additional dealership programming required for most functions.
Where is the BCM located on a 2009 Sierra Denali?
The BCM is located inside the cabin, under the driver’s side of the dashboard, typically near the steering column and fuse box area.
Will this fix my airbag light and DTC B1001?
A faulty BCM is a common cause for an airbag light with code B1001. Replacing it often resolves the issue, but you may need to perform an ‘SDM Key Sync’ procedure with a high-level scan tool after installation to clear the light.
Do I need to send my old part back?
No. This product has no core charge, so you can keep your original module without any extra fees or hassle.