Is Your Sierra 2500 Plagued by Electrical Gremlins?
If your 2013 GMC Sierra 2500 is experiencing bizarre electrical issues like flickering lights, unresponsive power windows, a dead HVAC system, or random warning lights on the dash, a failing Body Control Module (BCM) is the most likely culprit. The BCM acts as the central command center for your truck’s body electronics, and when it fails, it can cause a cascade of frustrating and seemingly unrelated problems. Don’t let a faulty module sideline your truck. This genuine GM BCM, part number 20939138, is the definitive solution to restore your vehicle’s functionality and peace of mind.
From the Diagnostic Bay
We had a 2013 Sierra 2500 come in with the strangest symptoms. The owner said his radio would turn off, the dome light would stay on, and the power locks worked intermittently. He’d already replaced the battery and checked fuses with no luck. After connecting our scanner, we saw multiple communication loss codes with various modules. This pointed us directly to the BCM. A quick check of the ground wires confirmed they were solid, isolating the module itself as the failure point. We installed a VIN-programmed BCM, and within 10 minutes, every single electrical issue was resolved. The truck was back to normal, and the owner was thrilled to have his reliable workhorse back without a costly trip to the dealer.
Symptoms of a Failing 2013 Sierra 2500 BCM
- ✔ Power windows, door locks, or mirrors not working or operating erratically.
- ✔ Interior or exterior lights staying on, not turning on, or flickering.
- ✔ HVAC and climate control functions are unresponsive or the blower motor works intermittently.
- ✔ The security system malfunctions, causing no-start conditions or random alarm activation.
- ✔ An airbag warning light is illuminated on the dashboard, often with DTC B1001.
- ✔ Wipers behaving erratically or not working at all.
- ✔ False warnings appearing on the driver information center (DIC).
The Plug-and-Play Solution
Replacing a BCM used to mean a mandatory trip to the dealership for expensive programming. Our process eliminates that step entirely. We pre-program this module to your truck’s specific Vehicle Identification Number (VIN) before shipping. This ensures that it communicates perfectly with your vehicle’s existing systems right out of the box. It arrives ready for a straightforward, plug-and-play installation, saving you time, money, and the headache of scheduling a dealer appointment.
This module is a direct replacement for a wide range of GM trucks and SUVs from 2007-2013 and is interchangeable with part numbers including 25844480, 25835966, 15943678, 25790508, 20939137, and 22860591.
Frequently Asked Questions
Do I need to have this BCM programmed by a dealer?
No. We pre-program the module to your vehicle’s VIN before it ships. It will arrive ready to install with no additional programming required, saving you hundreds of dollars.
Where is the BCM located on my 2013 Sierra 2500?
The BCM is typically located under the driver’s side dashboard, near the steering column. Installation usually takes less than 15 minutes with basic hand tools.
What if my airbag light is on after installation?
If the airbag light appears after installing the new BCM, it means the module needs to be synced with the airbag system. This is a simple procedure called ‘Setup SDM Primary Key in BCM’ that can be performed with a professional-grade diagnostic scan tool.
Is there a core charge for this part?
No, there is no core charge. You can keep your old module without any hassle or need to return it.
Will this fix my specific electrical problem?
This module corrects issues directly caused by a failing BCM, such as the symptoms listed above. While it is the most common source of these problems, always ensure your vehicle’s wiring and grounds are in good condition.