Is your 2009 GMC Sierra 1500 running rough, stalling unexpectedly, or showing a persistent check engine light? These frustrating issues often point to a failing Engine Control Module (ECM), the central computer of your truck’s powertrain. A faulty ECM can disrupt everything from fuel delivery and ignition timing to transmission shifting, making your reliable truck feel unpredictable. Don’t let a bad module keep you off the road. This direct-fit engine computer, part number 12629009, is the definitive solution to restore your vehicle’s performance and reliability.
Unlike sourcing a used module from a junkyard that would require an expensive trip to the dealership for programming, our ECMs come fully programmed to your truck’s specific Vehicle Identification Number (VIN). We install the latest, most stable software updates from GM, ensuring optimal performance, fuel efficiency, and emissions control. This means you receive a part that is truly plug-and-play, getting you back on the road faster and with less hassle.
Common Symptoms of a Failing GM Engine Computer
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Noticeable decrease in fuel economy.
- ✔ Rough or erratic idling.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Communication errors when using a diagnostic scan tool.
From the Diagnostic Bay
We recently had a 2009 Silverado in the shop with a classic case of “parts cannon” diagnostics. The owner had replaced the throttle body, MAF sensor, and all four oxygen sensors trying to chase down a stalling issue and a P0171 code (System Too Lean). After spending over a thousand dollars on parts, the problem persisted. A quick check of the ECM’s data stream showed erratic fuel trim adjustments that made no sense. We installed one of our VIN-programmed modules, performed the 10-minute security relearn, and the truck ran perfectly. The root cause was the ECM all along. Don’t waste time and money guessing—start with the brain of the operation.
The Right Choice for Your 2009 Sierra 1500 Engine Computer
Choosing the correct replacement part is critical for your vehicle’s health. This module is a guaranteed fit for a wide range of GM trucks, vans, and SUVs from the 2009-2010 model years, including the Silverado, Tahoe, Suburban, Escalade, and Express van. By providing us with your VIN during checkout, you ensure that the 2009 Sierra 1500 Engine Computer you receive is perfectly matched to your vehicle’s factory options, emissions standards, and powertrain configuration. This precise calibration is key to restoring the smooth, efficient operation you expect from your truck.
Installation is straightforward for any DIY mechanic or professional technician. In most cases, it involves disconnecting the battery, unplugging the electrical connectors from the old ECM, unbolting it from its bracket in the engine bay, and installing the new one in its place. After reconnecting the battery, you may need to perform a simple security relearn procedure, which does not require any special tools and instructions can be easily found online or in your service manual.
Frequently Asked Questions
Do I need to have this engine computer programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before we ship it. It arrives ready for installation, saving you the time and expense of a dealership visit.
What information do you need from me?
After you place your order, we will need the 17-digit Vehicle Identification Number (VIN) from your truck. You can find this on your dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Is this a simple plug-and-play installation?
Yes, for the most part. The module is programmed to be plug-and-play. However, on many GM vehicles, you may need to perform a simple security relearn procedure (often called a “key relearn”) after installation. This procedure takes about 10-15 minutes and does not require any special tools.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM, then yes, this part will resolve the issue. It’s crucial to ensure your vehicle’s underlying mechanical or sensor issues have been addressed first, as the ECM can only function correctly with good inputs from the rest of the vehicle.
What part numbers does this replace?
This module is a direct replacement for part numbers 12629009 and 12625455, ensuring broad compatibility across many GM models.