Is Your Sierra 1500 Running Rough? Let’s Get It Fixed.
There’s nothing more frustrating than a truck that won’t cooperate. If you’re dealing with a persistent check engine light, poor fuel economy, stalling, or a no-start condition in your 2010-2013 Sierra 1500, a failing Engine Control Module (ECM) is a very likely culprit. As the brain of your truck’s 4.3L engine, the ECM controls everything from fuel injection to ignition timing. When it starts to fail, the symptoms can be unpredictable and maddening. You don’t need a new truck; you need a reliable, correctly programmed replacement for the heart of its electronics.
The Direct Solution: A Pre-Programmed Engine Control Module
Forget expensive dealership visits and the hassle of finding a shop that can flash a new computer. We provide a straightforward solution. This ECM, service number 12635043, is professionally programmed to your truck’s specific Vehicle Identification Number (VIN) before it ever leaves our facility. We install the latest, most stable software updates from GM, ensuring optimal performance and compatibility. This isn’t just a part; it’s a complete, ready-to-install fix.
“A customer’s 2011 Sierra 1500 with the 4.3L came in last week with an intermittent no-start and random stalling that left him stranded twice. He had already replaced the fuel pump on another mechanic’s advice, but the problem persisted. After scanning, we found no communication with the ECM at times. Instead of just swapping parts, we checked the main power and ground pins at the ECM connectorโthey were solid. This confirmed the fault was internal to the module itself. A failing driver circuit inside the original ECM was intermittently cutting power to the fuel pump relay. After installing one of our pre-programmed units, the truck fired up instantly and has been running perfectly ever since. It’s a classic case where the symptoms point one way, but the real problem is the computer.”
Common Symptoms of a Failing 2010-2013 Sierra 1500 ECM:
- โ Persistent Check Engine Light (CEL) with various communication or sensor codes.
- โ Engine stalling, stumbling, or hesitating during acceleration.
- โ Complete no-start condition where the engine cranks but won’t fire.
- โ Noticeable decrease in fuel mileage.
- โ Harsh or erratic automatic transmission shifting.
- โ Misfire codes that don’t resolve after replacing plugs, wires, or coils.
Plug-and-Play Installation: No Dealer Visit Required
Installing your new ECM is a job most DIYers can handle in under an hour with basic tools. Hereโs how you do it on your Sierra 1500:
- Safety First: Disconnect the negative terminal from your truck’s battery.
- Locate the ECM: On your Sierra, the ECM is located on the driver’s side, in front of the wheel well, underneath the battery tray.
- Access the Module: You will need to remove the battery and the battery tray to gain clear access to the ECM.
- Disconnect Connectors: Carefully unplug the electrical connectors from the old ECM. They have locking tabs that need to be released. Inspect the connectors for any corrosion or damage and clean them if necessary.
- Remove Old ECM: Unbolt the old module from its mounting bracket and remove it from the vehicle.
- Install New ECM: Mount your new, pre-programmed ECM onto the bracket and securely plug in the electrical connectors. You should hear a ‘click’ as they lock into place.
- Reassemble: Reinstall the battery tray and the battery. Reconnect the negative battery terminal.
- Final Step: Your truck is now ready to start. In some cases, a security relearn procedure may be required, which can typically be done without special tools by cycling the key.
Guaranteed Fitment & Compatibility
This module is a direct replacement for vehicles equipped with the 4.3L V6 engine and is compatible with several service numbers. Please verify your part number before ordering.
- Compatible Service Numbers: 12635043, 12639471, 12653246
- Fits These Models:
- 2010-2013 GMC Sierra 1500 (4.3L)
- 2010-2013 Chevrolet Silverado 1500 (4.3L)
- 2010-2014 GMC Savana 1500 Van (4.3L)
- 2010-2014 Chevrolet Express 1500 Van (4.3L)
IMPORTANT: After your purchase, we will contact you to request your vehicle’s VIN. This is a critical step, as we cannot ship your part until we program it specifically for your truck.