If you’re dealing with bizarre electrical problems in your 2015 Sierra Denali 3500—like lights flashing randomly, power windows with a mind of their own, or a security system that won’t cooperate—you’ve likely pinpointed the culprit: a failing Body Control Module (BCM). As a technician with over two decades of experience, I’ve seen how a faulty BCM can turn a reliable truck into a source of constant frustration. The dealership solution often involves a brand new module and several hours of expensive programming. We offer a smarter, more direct path to getting your truck back in order.
This is a comprehensive mail-in cloning service. You simply purchase this service, ship your original BCM to us, and we handle the rest. We will transfer all the critical vehicle-specific data from your original module to this fully tested replacement unit. The result is a true plug-and-play solution. When you receive it back, you can install it yourself and bypass the need for dealer-specific scan tools or programming appointments. It’s the most efficient way to restore your vehicle’s functionality.
From the Diagnostic Bay: The Case of the Haunted Truck
A customer brought in a 2015 Silverado 2500, a cousin to the Sierra, with a list of complaints that sounded like something out of a ghost story. The dome lights would flicker while driving, the horn would chirp randomly when locked, and the radio would sometimes refuse to turn off after the key was removed. He was convinced the truck was possessed. After ruling out battery and ground issues, my scanner pointed to a series of communication errors all originating from the BCM (multiple U-codes). On these trucks, the BCM is located under the steering column, and it’s not uncommon for water intrusion from a leaky windshield cowl seal to drip down and cause corrosion on the board. After pulling his module, that’s exactly what we found. Instead of a costly new unit and programming, we used a cloned 2015 Sierra BCM to get him back on the road the next day with all the gremlins banished for good.
Is Your Truck Showing These BCM Failure Signs?
- ✔ Erratic or non-functional interior and exterior lights (headlights, taillights, dome lights).
- ✔ Power windows, door locks, or mirrors operating intermittently or not at all.
- ✔ Vehicle security system or keyless entry malfunctions (e.g., alarm sounding for no reason).
- ✔ Instrument cluster warnings or lights that are incorrect or stay on.
- ✔ Communication failure diagnostic trouble codes (DTCs), such as U0140, U0155, or other U-codes.
- ✔ Wipers or radio behaving unpredictably.
Your Straightforward BCM Installation Guide
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- ✔ Locate the Module: On most 2015 GM trucks like the Sierra, the BCM is located under the driver’s side dashboard, near the steering column. You may need to remove a lower dash panel for access.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old BCM. They have locking tabs that need to be depressed. Once disconnected, unbolt or unclip the module from its mounting bracket.
- ✔ Install the New Module: Seat the replacement BCM into the mounting bracket and plug in all the electrical connectors firmly until they click into place.
- ✔ Reconnect and Test: Reconnect the negative battery terminal. Start the vehicle and test all related functions: lights, locks, windows, wipers, and radio to ensure proper operation.
Important Post-Installation Notes
While our cloning service makes this a near plug-and-play repair, some vehicle systems may require a ‘handshake’ with the new BCM. Please be aware of the following possibilities:
- Airbag System Sync: If your airbag warning light illuminates after installation, a simple ‘Setup SDM Primary Key in BCM’ procedure is needed. This requires a professional-grade scan tool to sync the systems and is not indicative of a faulty part.
- 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.
Verified Vehicle Compatibility List
This programming service and module are guaranteed to be compatible with the following vehicles and part numbers. Please match your part number to ensure a perfect fit. Alternate Part Numbers: 13592137, 13506936, 13587704, 13594764
- ATS: 2015-2016 (on firewall)
- Corvette: 2015 (LH dash)
- CTS: 2015-2016 (Sdn, LH dash)
- Escalade & Escalade ESV: 2015 (under steering column)
- Impala: 2015-2016 (New Style, LH dash)
- Sierra 1500 / Denali 1500: 2015 (under steering column)
- Sierra 2500 / 3500 / Denali 2500 / Denali 3500: 2015 (under steering column or LH firewall)
- Silverado 1500 / 2500 / 3500: 2015 (under steering column)
- Sonic: 2015-2018 (RH rear quarter panel)
- Suburban 1500: 2015 (under steering column)
- Tahoe: 2015 (under steering column)
- XTS: 2015 (left front hinge pillar)
- Yukon & Yukon XL 1500: 2015 (under steering column)
Frequently Asked Questions
How does the mail-in cloning service work?
After you place your order, we will contact you with instructions to ship your original BCM to our facility. Once we receive it, we extract the vehicle-specific data and transfer it to the replacement module. We then ship the ready-to-install BCM back to you.
Do I need to get this programmed by a dealer after I receive it?
No. Our cloning service makes this a plug-and-play part. All the necessary programming from your original module is transferred, so you can avoid expensive dealer programming fees.
Is there a core charge or do I need to return my old BCM?
You must send us your original BCM for the data cloning service, but there is no separate core charge, and you do not need to return it after receiving the replacement. You can keep your original module.
Will this fix the specific problems my truck is having?
This module will fix issues directly caused by a faulty BCM. If you are experiencing problems like erratic lights, non-working power accessories, or security system faults, a failing BCM is the most likely cause. Proper diagnosis is always recommended.
What if the airbag light comes on after I install it?
This is not a defect. Some GM vehicles require the new BCM to be electronically introduced to the airbag system (SDM). This is a simple ‘Setup SDM Primary Key’ procedure that can be performed with a professional scan tool.