Restore Full Electrical Function to Your GM SUV
Are you battling frustrating electrical gremlins in your GMC Envoy, Chevy Trailblazer, or Oldsmobile Bravada? Intermittent power windows, flickering lights, a malfunctioning security system, or an unexplained battery drain are all 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 cause a wide range of seemingly unrelated problems. This pre-programmed BCM is the definitive solution to restore your vehicle’s comfort and convenience features to perfect working order.
The Critical Role of the Body Control Module
The BCM is responsible for managing a vast array of non-engine related functions. It interprets inputs from switches (like your window or lock buttons) and sensors, and sends commands to operate various accessories. When it fails, communication breaks down, leading to the erratic behavior you’re likely experiencing. This isn’t just a simple component; it’s a vital computer that ensures everything from your interior lights to your windshield wipers operates as the manufacturer intended.
From the Diagnostic Bay
We once had a 2004 Trailblazer in the shop with a persistent battery drain that had the owner at his wit’s end. He had already replaced the battery twice and the alternator once, but the vehicle would be dead every two or three days. After hooking up a multimeter, we found a significant parasitic draw. By pulling fuses one by one, we isolated the draw to the BCM circuit. The faulty BCM wasn’t allowing the vehicle’s data network to go to sleep, keeping multiple systems active long after the key was off. A new, programmed BCM solved the problem instantly, saving the customer from any more wasted time and money on incorrect diagnoses.
Common Symptoms of a Failing BCM
- ✔ Power windows, door locks, or mirrors working intermittently or not at all.
- ✔ Interior dome lights, dashboard illumination, or exterior lights staying on or failing to activate.
- ✔ Erratic behavior from headlights, taillights, or turn signals.
- ✔ The security system engaging randomly, causing false alarms or a no-start condition.
- ✔ Windshield wipers or radio turning on and off by themselves.
- ✔ A persistent dead battery caused by a parasitic electrical draw.
- ✔ Diagnostic trouble codes related to communication errors between modules (U-codes).
Your Direct-Fit, VIN-Programmed Solution for 2004-2005 Envoy BCM
Forget the hassle and expense of a dealership visit. We provide a fully programmed 2004-2005 Envoy BCM that is ready for installation upon arrival. Simply provide us with your vehicle’s VIN during checkout, and our technicians will flash the module with the latest GM software specific to your vehicle’s build. This ensures seamless integration and proper function of all your vehicle’s options. This part is a direct replacement for multiple part numbers, including 15122670, 15065293, 15114669, 15191621, and 9352135.
Installation & Required Procedures
Installation is straightforward for a DIY mechanic with basic tools. The BCM is typically located on the fuse box or, in the case of the Envoy XUV, under the rear floor panel. After physically installing the module, some additional electronic steps may be required to ensure all systems are synchronized.
- Airbag System Sync: If the airbag warning light is illuminated after installation, a professional scan tool must be used to perform the ‘Setup SDM Primary Key in BCM’ procedure. This syncs the new BCM with the airbag module.
- Brake Pedal Position Relearn: In some cases, a brake pedal position sensor recalibration may be necessary to ensure correct brake light operation and traction control system performance.
Always consult a factory service manual or a qualified technician for vehicle-specific instructions.
Frequently Asked Questions
Do I need to send my original BCM back?
No, there is no core charge for this part. You can keep your original module.
Is this BCM difficult to install?
The physical replacement is a moderate-level task. However, post-installation procedures like the airbag system sync may require a professional-grade diagnostic tool that most DIY mechanics do not own.
What happens if I forget to provide my VIN?
We cannot ship your order without a VIN. The programming is essential for the BCM to function correctly in your specific vehicle. We will contact you to get the VIN before processing the order.
Will this fix my “Service 4WD” light?
While the BCM communicates with many systems, a “Service 4WD” message is most often caused by a fault in the Transfer Case Control Module (TCCM), not the BCM. It is important to diagnose the specific cause of the light before ordering parts.
My airbag light came on after installation. Is the part defective?
No, this is an expected outcome. The new BCM needs to be electronically introduced to the vehicle’s airbag system. A technician must perform the ‘Setup SDM Primary Key in BCM’ procedure to sync the modules and turn off the light.