Restore Peak Performance to Your GM Vehicle
Is your Chevrolet Sonic, Cruze, or Aveo suddenly stalling, running rough, or refusing to start? A faulty Engine Control Module (ECM) is often the culprit behind these frustrating and unpredictable issues. As the brain of your vehicle’s engine, the ECM controls everything from fuel mixture and ignition timing to transmission shifting. When it fails, it can cause a cascade of problems that can leave you stranded. This replacement ECM is the reliable, straightforward solution to get your car back on the road with confidence.
We take the guesswork and hassle out of the repair. Unlike sourcing a part from a salvage yard or buying a blank unit that requires expensive dealer tools, this ECM arrives at your door pre-programmed with the latest GM factory software. All we need is your vehicle’s 17-digit VIN during checkout. This ensures the module is a perfect match for your car’s specific configuration, making the installation process as simple as possible. For the professional mechanic or the dedicated DIYer, this is the most efficient way to complete the job correctly the first time.
From the Diagnostic Bay
I remember a 2012 Sonic that came into my shop with a maddeningly intermittent no-start condition. The owner had already replaced the battery and starter. Scans showed a U0100 Lost Communication with ECM code, but it wasn’t consistent. After checking the wiring harness for chaffing near the engine block—a common spot on these platforms—we found no issues. On a hunch, we tapped the ECM housing with a screwdriver handle and the engine immediately stalled. The internal processor was failing under vibration. Swapping in a pre-programmed 2012 Sonic ECM like this one provided a permanent fix, saving the customer from endless diagnostic fees.
Common Signs of a Failing Engine Computer
- ✔ Check Engine Light is on with communication or processor codes (e.g., P0601, P0606, U0100).
- ✔ Engine cranks but will not start.
- ✔ Intermittent stalling or rough idling for no apparent reason.
- ✔ A noticeable drop in fuel economy.
- ✔ Car is in “limp mode,” with reduced power and functionality.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass an emissions inspection.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow all systems to discharge.
- ✔ Locate the ECM: On most compatible models like the Sonic and Cruze, the ECM is typically found in the engine bay, mounted near the battery or on the firewall.
- ✔ Disconnect the Module: Carefully unplug the electrical wiring harnesses. These connectors have locking tabs that must be released before they can be pulled free.
- ✔ Remove the Old ECM: Unbolt the mounting hardware holding the original module in place and remove it from the vehicle.
- ✔ Install the New ECM: Mount your new, pre-programmed ECM and securely fasten the bolts. Reconnect the wiring harnesses, ensuring they click firmly into place.
- ✔ Reconnect the Battery: Re-attach the negative battery terminal.
- ✔ Perform Security Relearn: While the module is programmed, your vehicle’s anti-theft system may require a simple key-cycle relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual for the specific steps for your vehicle.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12679199, 12642927, 12636386, 12621466, and 12630789. It is guaranteed to fit the following vehicles:
- 2011-2012 Chevrolet Cruze (with 1.8L engine)
- 2009-2011 Chevrolet Aveo
- 2013 Chevrolet Spark
- 2013-2014 Chevrolet Trax (with 1.8L engine)
- 2012 Chevrolet Sonic (with 1.8L engine)
- 2009-2010 Pontiac Wave
- 2009-2010 Pontiac G3
Frequently Asked Questions
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the ECM with the exact software and calibrations for your car’s specific options, engine, and transmission. This ensures perfect compatibility and function right out of the box.
Is this a simple plug-and-play installation?
Yes, for the most part. Because we program the module to your VIN, it eliminates the need for dealer-level programming tools. However, you may need to perform a simple security or key relearn procedure, which can be done at home without any special tools.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of your original ECM (e.g., codes P0601-P0606), then this replacement module will solve the problem. It is crucial to properly diagnose the vehicle first to ensure the ECM is the root cause.
Do I need to return my old ECM?
This listing does not require a core return. You can keep your old part.
Is this a new or used part?
This is a high-quality, tested replacement part guaranteed to restore your vehicle’s original functionality. It is programmed with the newest stable software from GM for optimal performance.