If you’re dealing with baffling electrical problems in your GMC truck—like the radio acting possessed, power windows refusing to budge, or the A/C blower motor working only when it wants to—you’ve likely met the common failure point: the Body Control Module (BCM). As the central command for your truck’s body electronics, a faulty BCM can cause a cascade of frustrating issues. This replacement Body Control Module, equivalent to part number 25823559, is the definitive solution for your 2007-2010 Sierra Denali BCM and other compatible GM vehicles, arriving pre-programmed to your VIN for a hassle-free, direct-fit installation.
A Technician’s Notebook
I had a 2008 Sierra 2500 in the bay last month that was a perfect example of BCM failure. The customer complained of an intermittent no-start, a persistent airbag light, and flickering interior lights. A scan tool pulled a handful of communication codes and the infamous B1001. After verifying the main battery connections and grounds were solid (always the first step!), we honed in on the BCM. Swapping in a VIN-programmed module like this one not only cleared the codes but instantly solved all the electrical gremlins. The key was the pre-programming; it saved the customer a tow to the dealer and at least two hours of labor and programming fees.
Is Your Sierra Denali Showing These Electrical Gremlins?
A failing BCM doesn’t always present as a total failure. Often, it begins with intermittent symptoms that can be misdiagnosed. Here’s what to look for:
- ✔ Unresponsive or erratic power windows, door locks, and interior/exterior lighting.
- ✔ The security system acting up, leading to no-start or stalling conditions.
- ✔ HVAC controls that are dead or a blower motor that works intermittently.
- ✔ An illuminated airbag warning light, often with a DTC B1001 stored in the system.
- ✔ A variety of seemingly unrelated diagnostic trouble codes (DTCs) related to body systems.
- ✔ Poor grounding symptoms even after main grounds have been checked and cleaned.
Get Your Truck Back to Normal: A 5-Minute Installation Guide
One of the best parts of this module is that you don’t need to be a professional mechanic to install it. The process is straightforward and can be done with basic hand tools right in your driveway.
- Safety First: Always disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
- Locate the Module: The BCM is typically located under the driver’s side dashboard, to the left of the steering column. You may need to remove a lower dash panel for access.
- Swap the Connectors: Carefully unplug the electrical connectors from your old BCM. They have release tabs that need to be pressed. Plug them securely into your new module.
- Mount the New BCM: Secure the new Body Control Module in the same position as the old one. Reinstall any trim panels you removed.
- Reconnect and Test: Reconnect the negative battery terminal. Start your truck and test all functions: lights, wipers, windows, locks, and HVAC to ensure everything is working correctly.
Post-Installation Note: In some cases, you may need to perform a couple of simple relearn procedures. If your airbag light remains on, a professional scan tool is needed to perform the ‘Setup SDM Primary Key in BCM’ function. A Brake Pedal Position relearn may also be required for proper brake light and traction control operation. Our included instructions provide further details.
Will This Fit My Truck or SUV?
This module is a direct replacement for a wide range of General Motors vehicles. While it is a perfect fit for a 2007-2010 Sierra Denali BCM, please verify your model and year in the list below. This part is interchangeable with numerous part numbers, including 25823559, 25844480, 25835966, 20939137, and 22860591.
ESCALADE & ESV & EXT 07-11
SIERRA 1500 PICKUP 07-11 (07 new style)
SIERRA 2500/3500 PICKUP 07-13 (07 new style)
SIERRA DENALI 07-13 (07 new style)
SILVERADO 1500 PICKUP 07-11 (07 new style)
SILVERADO 2500/3500 PICKUP 07-13 (07 new style)
SUBURBAN 1500/2500 07-11
TAHOE 07-11
YUKON & YUKON XL 1500/2500 07-11
Frequently Asked Questions
Frequently Asked Questions
What does a Body Control Module (BCM) do in my Sierra Denali?
The BCM acts as the brain for your truck’s body electronics. It controls non-engine related functions like your power windows, door locks, interior and exterior lights, security system, wipers, and even the climate control system.
Is this part really ‘plug-and-play’?
Yes. We program the module to your vehicle’s specific VIN before shipping. This ensures it communicates correctly with your truck’s other systems right out of the box, eliminating the need for expensive dealership programming.
Why is my airbag light still on after installing the new BCM?
This is a normal security feature on GM vehicles. The BCM and the airbag’s Sensing and Diagnostic Module (SDM) need to be electronically ‘shaken hands’. This requires a ‘Setup SDM Primary Key in BCM’ procedure using a professional-grade scan tool to sync the two modules and turn off the light.
Do I need to send my old part back for a core charge?
No, there is absolutely no core charge. You can keep your old module without any hassle or extra fees.
What if I have installation questions?
We’re here to help. As experienced technicians, we can provide expert support to guide you through the process. Your purchase is backed by a one-year warranty for complete peace of mind.