Restore Your SUV’s Electrical Functions and Get Back on the Road
Is your GMC Envoy, Trailblazer, or other GM SUV acting possessed? One minute the power windows work, the next they don’t. Maybe your radio is acting up, the security light is flashing for no reason, or the gauges are going haywire. As a technician with over two decades of experience, I’ve seen these exact gremlins hundreds of times. More often than not, the culprit is a failing Body Control Module (BCM). This isn’t just an annoyance; it’s the central command center for your vehicle’s comfort and convenience features. When it fails, it can make your truck incredibly frustrating to drive.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and dealer expense out of the equation. By providing your vehicle’s VIN at checkout, you receive a BCM that is professionally flashed with the latest GM software specific to your 2004-2005 Envoy XUV BCM configuration. This means no expensive trips to the dealership for programming—a step that can often cost hundreds of dollars on its own. You get a reliable module that’s ready to restore order to your vehicle’s electronics right out of the box.
Case Study: The Frustrating Trailblazer
A customer brought in an ’04 Trailblazer with a list of complaints that seemed unrelated: the driver’s window wouldn’t go down, the rear wiper was stuck on, and the truck would occasionally refuse to start, showing only a security light. They had already replaced the battery and the window switch with no luck. After connecting my scan tool, I found a slew of ‘U’ codes, indicating a loss of communication between various modules. This is a classic sign. Instead of chasing individual components, I went straight to the BCM. After swapping in a new, correctly programmed module, every single issue vanished. It was a reminder that when multiple, unrelated electrical systems fail at once, the BCM should be your primary suspect.
Common Signs of a Failing BCM
- ✔ Power windows, door locks, or mirrors operating intermittently or not at all.
- ✔ Interior or exterior lights behaving erratically (staying on, not turning on).
- ✔ The security system light is illuminated, potentially causing a no-start condition.
- ✔ Instrument cluster gauges giving false readings or not working.
- ✔ Diagnostic trouble codes (DTCs) related to communication errors (U-codes) or BCM internal faults.
- ✔ Radio or climate control malfunctions.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- ✔ Locate the BCM: On the 2004-2005 Envoy XUV, the BCM is uniquely located under the rear floor panel. On most other compatible models (like the Trailblazer or standard Envoy), it’s part of the fuse box assembly under the rear seat on the driver’s side.
- ✔ Disconnect Connectors: Carefully release the locking tabs on the multiple electrical connectors plugged into the old BCM. They are color-coded, which helps with reassembly. Do not force them.
- ✔ Remove the Old Module: Unbolt or unclip the old BCM from its mounting bracket.
- ✔ Install the New BCM: Mount your new, pre-programmed BCM in place and securely reconnect all the electrical connectors into their corresponding slots.
Important Post-Installation Information
While this 2004-2005 Envoy XUV BCM is delivered ready for your vehicle, some GM platforms may require a simple relearn procedure for specific systems to communicate with the new module. This is normal. You may need a diagnostic tool capable of performing these functions:
- Airbag System Sync: If your airbag warning light is on after installation, a professional scan tool is needed to perform the ‘Setup SDM Primary Key in BCM’ procedure. This syncs the airbag system with the new BCM.
- Brake Pedal Position Relearn: On some models, a brake pedal position sensor relearn may be required to ensure your brake lights and traction control system function correctly.
And the best part? There is absolutely no core charge. You can keep your old module without the hassle of shipping it back.
Verified Vehicle Compatibility
This module is a direct replacement for part number 15122670 and also interchanges with 15065293, 15114669, 15191621, and 9352135. It is guaranteed to fit the following models (without security system where noted):
- 2004-2005 GMC Envoy XUV
- 2002-2005 GMC Envoy & Envoy XL
- 2002-2005 Chevrolet Trailblazer & Trailblazer EXT
- 2002-2004 Oldsmobile Bravada
- 2004-2005 Buick Rainier
- 2003-2005 Isuzu Ascender
- 2005 Saab 9-7X
This is the definitive solution for your 2004-2005 Envoy XUV BCM and a wide range of other GM SUVs experiencing frustrating electrical issues.
Frequently Asked Questions
What does a Body Control Module (BCM) do?
The BCM is a computer that acts as the central hub for your vehicle’s body electronics. It controls non-engine related functions like power windows, locks, interior lights, wipers, the security system, and the instrument cluster.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the BCM with the exact software and settings your specific vehicle model and options require. This makes the installation process plug-and-play and avoids a costly programming fee at a dealership.
Is this difficult to install myself?
For someone with basic mechanical skills, this is a very manageable task. The module is typically easy to access (under the rear seat or rear floor panel), and no special tools are needed for the physical swap. The key is our pre-programming service, which handles the most complex part of the job for you.
What if the airbag light comes on after I install it?
This can happen occasionally. It means the new BCM needs to be electronically introduced to the airbag system’s computer (SDM). A mechanic with a professional-grade scan tool can perform the ‘Setup SDM Primary Key in BCM’ procedure in a few minutes to resolve this.
Do I need to send my old BCM back?
No. We do not require a core return for this part. You can keep your original module, saving you time and the cost of return shipping.