Restore Full Control Over Your Truck’s Electronics
Are you battling a storm of bizarre electrical issues in your 2007-2010 GMC Sierra Denali? Flickering lights, a dead instrument cluster, power windows with a mind of their own, or a security system that randomly prevents your truck from starting are all classic signs of a failing Body Control Module (BCM). As the central nervous system for your vehicle’s comfort and convenience features, a faulty BCM can make driving frustrating and unpredictable. This replacement Body Control Module, corresponding to part number 25971916, is the definitive solution to get your truck back in perfect working order.
We take the guesswork and high cost out of the repair. Unlike a generic module from a parts store, each unit is professionally VIN-programmed before it ships. This means it arrives at your door ready for a true plug-and-play installation, with no need for an expensive trip to the dealership for programming. It’s designed to seamlessly communicate with your truck’s existing systems, restoring functionality and clearing persistent diagnostic trouble codes right out of the box.
Case Study: The Misleading Ground Fault
I once had a 2008 Sierra 2500 in the bay with all the symptoms of a dead BCM—no power to the radio, intermittent wipers, and a ‘Service 4WD’ message. The customer had already replaced the BCM himself with a non-programmed unit, but nothing changed. Before condemning another module, I went straight to the main BCM ground point (G218) located on the driver’s side A-pillar. Sure enough, it was loose and corroded. After cleaning and tightening the connection, all the electrical gremlins vanished. This is why I always tell my customers: when you replace your 2007-2010 Sierra Denali BCM, take five extra minutes to inspect and clean the main ground connections. It can save you from a world of diagnostic headaches.
Is Your Sierra Denali Showing These Electrical Faults?
- ✔ The security or anti-theft light stays on, causing a no-start condition.
- ✔ Power windows, door locks, or interior dome lights work intermittently or not at all.
- ✔ The HVAC blower motor is erratic or completely non-functional.
- ✔ An airbag warning light is illuminated, often with a DTC B1001 (Setup SDM Primary Key in BCM) code stored.
- ✔ Wipers, turn signals, or exterior lights behave erratically.
- ✔ The radio or infotainment system powers off unexpectedly.
- ✔ Communication errors with other modules on the CAN bus network (U-codes).
Your 5-Minute Installation Guide
- ✔ Safety First: Always disconnect the negative terminal from your truck’s battery before working on any electronic components.
- ✔ Locate the BCM: On most GMT900 trucks, the Body Control Module is located under the driver’s side of the dashboard, to the left of the steering column. It’s a black box with multiple large electrical connectors.
- ✔ Swap the Module: Carefully unplug the electrical connectors from the old BCM. They have locking tabs that need to be depressed. Once unplugged, unclip the module from its mounting bracket and remove it.
- ✔ Install the New BCM: Snap your new, pre-programmed BCM into the mounting bracket and securely reconnect all the electrical 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 functions: lights, locks, windows, wipers, and the HVAC system to confirm the repair.
- ✔ Post-Install Check: In some cases, particularly if the airbag light was on, you may need a professional scan tool to perform the ‘Setup SDM Primary Key in BCM’ function to sync the new BCM with the airbag system. A ‘Brake Pedal Position Relearn’ may also be required on certain models.
Verified Fitment for Your GM Truck or SUV
This module is a direct replacement for part number 25971916 and other interchangeable numbers across a wide range of General Motors vehicles. While this page focuses on the 2007-2010 Sierra Denali BCM, it is also confirmed to fit the following models. Always verify your original part number for a perfect match.
GMC
- ✔ Sierra 1500/2500/3500 (2007-2013)
- ✔ Sierra Denali (2007-2013)
Chevrolet
- ✔ Silverado 1500/2500/3500 (2007-2013)
- ✔ Avalanche 1500 (2007-2011)
- ✔ Suburban 1500/2500 (2007-2011)
- ✔ Tahoe (2007-2011)
Cadillac
- ✔ Escalade, ESV, EXT (2007-2011)
Frequently Asked Questions
Does this BCM really come programmed?
Yes. We program the module to your vehicle’s specific VIN before shipping. This ensures it works correctly with the options your truck was built with, eliminating the need for dealer programming.
Is this a difficult part for a DIYer to install?
The physical installation is very straightforward and typically takes less than 15 minutes with basic tools. It’s located under the driver’s side dash and simply unplugs. The only potential complication is the need for a scan tool to perform a relearn procedure if the airbag light remains on.
What is the ‘SDM Key Sync’ procedure you mentioned?
The SDM (Sensing and Diagnostic Module, i.e., the airbag computer) is linked to the BCM for security. If you replace the BCM, the airbag light may come on. The ‘Setup SDM Primary Key in BCM’ procedure uses a bidirectional scan tool to re-establish this link and turn off the light. Many independent shops can perform this if needed.
Do I need to send my old BCM back?
No. There is absolutely no core charge for this part. You can keep your old module without any hassle or extra fees.
Will this fix my ‘Service 4WD’ message?
In many cases, yes. The BCM communicates with the Transfer Case Control Module (TCCM). A faulty BCM can disrupt this communication and trigger 4WD warnings. However, you should always perform a full diagnostic scan, as the issue could also be the TCCM itself or the selector switch.