Is Your 2007-2009 Sierra 1500 Running Rough?
If you’re dealing with a persistent check engine light, poor fuel economy, engine stalling, or a no-start condition in your GMC Sierra, a failing Engine Control Module (ECM) is a very likely culprit. The ECM is the central computer of your truck’s powertrain, responsible for managing everything from fuel injection and spark timing to transmission shifting and emissions control. When it fails, it can cause a wide range of frustrating and difficult-to-diagnose issues.
Don’t let a faulty computer keep your reliable truck off the road. This is a direct-fit replacement ECM, part number 12629020 (interchangeable with 12597125 and others), that arrives at your door fully programmed to your truck’s specific Vehicle Identification Number (VIN). We handle the complex programming, so you can focus on the straightforward installation.
From the Diagnostic Bay
We had a 2008 Sierra 1500 with the 4.3L V6 come into the shop with an intermittent stalling problem and a handful of seemingly unrelated trouble codes (O2 sensor, random misfire, etc.). The owner had already replaced two oxygen sensors and a set of spark plugs with no improvement. After hooking up our diagnostic scanner and monitoring live data, we noticed the fuel trim values were erratic and inconsistent. Instead of continuing to chase individual sensor codes, we tested the ECM’s power and ground circuits, which checked out fine. This pointed us directly to an internal failure in the module itself. We installed a VIN-programmed ECM, performed the security relearn, and the truck ran perfectly. The customer was thrilled to have a simple, final solution after wasting time and money on unnecessary parts.
Common Symptoms of a Failing ECM
- ✔ Check Engine Light is illuminated with various trouble codes
- ✔ Engine cranks but refuses to start
- ✔ Stalling, stumbling, or hesitation during acceleration
- ✔ Noticeable decrease in fuel efficiency
- ✔ Rough or erratic idling
- ✔ Harsh or incorrect automatic transmission shifting
- ✔ Communication errors with diagnostic scan tools
Why Choose Our Programmed 2007-2009 Sierra ECM?
Ordering an engine computer online can be confusing, but we make it simple. This isn’t just a used part pulled from a junkyard. Each module is meticulously inspected and then programmed with the latest, most up-to-date software directly from GM for your specific vehicle. By providing us with your VIN during checkout, you ensure that the computer is calibrated for your truck’s exact engine, transmission, and emissions equipment. This eliminates compatibility issues and ensures optimal performance right out of the box.
This module is a reliable solution for your 2007-2009 Sierra ECM failure. Once installed, you will need to perform a simple security relearn procedure (often called a key relearn or anti-theft relearn), which pairs the new module to your vehicle’s keys. This procedure typically takes 10-30 minutes and does not require any special tools. Instructions are widely available online or in your vehicle’s service manual.
Broad Compatibility Across the GM Lineup
While this is a primary replacement for the 2007-2009 Sierra ECM, this versatile E38-style computer is also a direct fit for a wide range of other GM cars, trucks, and vans. This includes models like the Chevrolet Silverado, Express/Savana Van, Cobalt, HHR, Malibu, Impala, and more. Please verify the service number on your original module or check the fitment list to confirm compatibility with your specific vehicle.
Frequently Asked Questions
Do I need to program this ECM?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s 17-digit VIN when you place your order, and the module will arrive flashed with the latest GM software for your specific configuration.
What is a VIN and why do you need it?
The VIN (Vehicle Identification Number) is a unique code for your specific vehicle. It contains critical information about the engine, transmission, body style, and factory options. We use the VIN to load the exact software and calibrations your truck needs to run correctly.
Will this part fix my truck’s problems?
This module will resolve any issues directly caused by a faulty ECM. However, it’s essential to ensure your vehicle has been properly diagnosed. This part will not fix problems related to faulty sensors, wiring, or other mechanical components. If you are unsure, we recommend consulting a professional technician.
Is a security relearn procedure required after installation?
Yes. After installing the new ECM, you must perform a security relearn procedure to sync the module with your vehicle’s anti-theft system. This is a simple process that you can typically do yourself in about 30 minutes with just the ignition key. Instructions are readily available for your specific model.
Which service numbers does this part replace?
This ECM, part number 12629020, is a direct replacement for several service numbers, including 12597125, 12612397, 12594750, 12629019, 12635902, and 12611549, among others. Always match the part number or consult our fitment guide to ensure compatibility.