Restore Full Functionality to Your GM Truck or SUV
Is your Sierra, Silverado, or Tahoe suffering from baffling electrical problems? One moment the power windows won’t work, the next the A/C is dead, or a persistent airbag light refuses to go away. These frustrating, seemingly random issues often point to a single culprit: a failing Body Control Module (BCM). As the central command for your vehicle’s body electronics, a faulty BCM can wreak havoc. This replacement module, a direct fit for part number 25790509, is the definitive solution to get your vehicle’s features working reliably again.
We take the guesswork and dealer expense out of the equation. Each module is expertly programmed to your vehicle’s specific VIN before shipping. This ensures that it communicates flawlessly with your truck’s other systems right out of the box. For the DIY mechanic or the professional shop, this means no expensive scan tools or programming subscriptions are needed for the initial setup. It’s a straightforward fix for a complex problem.
A Technician’s Notebook
I recently had a 2011 Sierra Denali 2500 BCM case that had another shop stumped. The customer complained of the radio turning off randomly, the driver’s side power lock working intermittently, and an airbag light that wouldn’t clear, even after replacing a sensor. Scanning the vehicle showed a slew of communication codes (U-codes) and a specific B1001 for the SDM. Instead of chasing individual components, we checked the BCM’s power and ground connections—they were solid. The combination of unrelated faults across different systems was the classic signature of an internally failing BCM. A new, VIN-programmed module fixed every single issue in one shot, including allowing the SDM key relearn to complete successfully.
Is Your GM Vehicle Showing These Telltale Signs?
A failing BCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs attention. This is especially true if you see multiple symptoms at once.
- ✔ The HVAC blower motor works only on high speed or not at all.
- ✔ Annoying electrical gremlins like flickering interior lights, malfunctioning wipers, or unresponsive power door locks.
- ✔ The dreaded airbag warning light is on, often with a Diagnostic Trouble Code (DTC) like B1001.
- ✔ Your vehicle’s security system acts up, causing no-start conditions or stalling.
- ✔ A scan tool reveals various body-related DTCs that keep returning after being cleared.
A Straightforward Guide to Your BCM Installation
Replacing the BCM is a job most owners can handle in their own driveway in under 15 minutes. Its location under the driver-side dashboard makes it easily accessible.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before working on any electronic components.
- Locate the Module: The BCM is typically found under the steering column, secured with clips or a few small bolts. You may need to remove a lower dash panel for access.
- Swap the Connectors: Carefully disconnect the several large electrical connectors from the old BCM. They have locking tabs, so be sure to depress them fully before pulling. Connect them securely to your new module.
- Secure the New BCM: Mount the new module in the same location as the old one and re-install any panels you removed.
- Reconnect and Test: Reconnect the battery terminal. Start the vehicle and test all functions: lights, locks, windows, wipers, and HVAC to confirm the repair.
- Post-Install Checks: In some cases, an airbag light may persist. This requires a scan tool with special functions to perform the ‘Setup SDM Primary Key in BCM’ procedure. Similarly, a Brake Pedal Position Relearn might be needed. This is not a sign of a bad part, but a necessary security handshake between modules.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of popular General Motors trucks and SUVs. It is interchangeable with numerous part numbers, including 25844480, 25835966, 15943678, and your original 25790509. Please verify your vehicle is on the list below for guaranteed compatibility.