Restore Full Electrical Function to Your GM SUV
Are you experiencing frustrating and unpredictable electrical problems in your Chevrolet Trailblazer, GMC Envoy, or other GM GMT360 platform vehicle? Issues like flickering lights, malfunctioning power windows and locks, a parasitic battery drain, or strange warnings on your dash are classic symptoms of a failing Body Control Module (BCM). The BCM acts as the central nervous system for your vehicle’s body electronics, and when it malfunctions, it can make your truck feel haunted. This replacement BCM is the definitive solution to restore your vehicle’s functionality and reliability.
We eliminate the complexity and high cost of a dealership repair. This module is professionally programmed to your vehicle’s specific VIN before it ships. It arrives loaded with the latest GM software updates, which can correct original factory flaws and improve overall performance. This means no expensive trips to the dealer for programming—it’s designed for a straightforward installation process.
Common Symptoms of a Failing BCM
- ✔ Erratic or non-functional power windows, door locks, and mirrors.
- ✔ Interior dome lights or exterior lights staying on, flickering, or not working at all.
- ✔ A persistent parasitic battery drain that kills your battery overnight.
- ✔ The security system light is on, or the vehicle intermittently fails to start.
- ✔ HVAC (A/C and heater) controls behaving unpredictably or not responding.
- ✔ False dashboard warnings, such as ‘Door Ajar’ or other incorrect alerts.
- ✔ Wipers operating on their own or not working when commanded.
From the Diagnostic Bay
We had a 2004 GMC Envoy come into the shop with a classic ‘haunted truck’ complaint. The owner said the battery would be dead every few mornings, and sometimes the interior lights would flicker while driving. After confirming the battery and alternator were healthy, we performed a parasitic draw test and traced it directly to the BCM. The module wasn’t entering its ‘sleep’ mode correctly, keeping other systems awake and draining the battery. Installing a VIN-programmed Trailblazer Envoy BCM like this one was the complete fix. It immediately solved the battery drain and all the strange electrical gremlins.
Why Choose Our Pre-Programmed BCM?
This isn’t just a replacement part; it’s a comprehensive repair solution. By programming the module to your VIN, we ensure it communicates perfectly with your vehicle’s other computers, like the ECU and instrument cluster. This unit is a direct replacement for multiple part numbers, including 15122670, 15065293, 15114669, 15191621, and 9352135. Best of all, there is no core charge. You can keep your original module without the hassle of shipping it back.
Installation and Required Procedures
The BCM is typically located as part of the front interior fuse box. While the physical installation is straightforward for a DIYer with basic tools, some vehicles may require additional electronic calibration steps after the new module is installed. Please be aware of the following potential procedures:
- Airbag System Sync: If your airbag warning light illuminates after installation, a ‘Setup SDM Primary Key in BCM’ procedure is necessary. This requires a professional-grade scan tool to sync the BCM with the airbag system and clear the light.
- Brake Pedal Position Relearn: On some models, a recalibration of the brake pedal position sensor may be needed to ensure proper function of the brake lights and traction control system.
We always recommend consulting a factory service manual or a qualified technician if you are unsure about any part of the installation process. By purchasing this pre-programmed Trailblazer Envoy BCM, you are taking the most critical and difficult step—the programming—out of the equation.
Frequently Asked Questions
What is a BCM and what does it control?
The Body Control Module (BCM) is a computer that manages your vehicle’s non-engine-related functions. This includes power windows, locks, interior and exterior lighting, wipers, the security system, and HVAC controls.
Is this BCM really plug-and-play?
Because we program it to your vehicle’s VIN before shipping, it eliminates the need for dealer programming. In most cases, it is a plug-and-play installation. However, as noted, some vehicles may require a simple relearn procedure for the airbag or brake systems, which can be done with a capable scan tool.
How do I provide my VIN for programming?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship the module until we receive this information, as the programming is specific to your exact vehicle.
Will this fix my parasitic battery drain?
A faulty BCM is one of the most common causes of a parasitic battery drain on these GM SUVs. If the BCM fails to go into sleep mode, it will keep other modules awake, draining the battery. While other causes are possible, replacing a faulty BCM is a very common and effective fix for this issue.
Do I need to return my old BCM?
No. This product has no core charge. You can keep your original module, which saves you the time and expense of return shipping.