Restore Your Vehicle’s Performance and Reliability
Is your Chevrolet Sonic, Cruze, or other compatible GM vehicle suddenly giving you headaches? Maybe it’s a no-start condition that leaves you stranded, rough idling that makes every stoplight a gamble, or a persistent Check Engine Light that just won’t go away. As a technician with over two decades of experience under the hood, I’ve seen these exact symptoms hundreds of times. More often than not, the culprit is a failing Engine Control Module (ECM), the electronic brain of your vehicle.
When an ECM’s internal components or software begin to fail, it can create a cascade of frustrating and seemingly unrelated problems. It controls everything from fuel injection and ignition timing to transmission shifting and emissions systems. A faulty module can lead to poor fuel economy, failed emissions tests, and unpredictable performance. This isn’t just an annoyance; it’s a critical component failure that needs a reliable solution.
This is a direct-replacement 2012-2016 Sonic Engine Control Module, and it’s the most straightforward fix you can get. We take all the guesswork and hassle out of the repair. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and our experts will program the module with the latest, most stable software updates directly from GM. It arrives at your door ready to install, saving you a costly trip to the dealership and their expensive programming fees.
A Technician’s Notebook: The Phantom Misfire Case
I remember a 2014 Chevy Cruze with the 1.4L turbo—same family as the Sonic—that came into my bay with a random misfire code (P0300) that no one could solve. The owner had already replaced plugs, coils, and even a fuel injector. The car ran terribly, especially under a light load. After confirming fuel pressure and compression were good, my gut told me to look at the ECM. On these specific GM platforms, I’ve seen internal ECM driver failures cause weak or erratic spark commands that don’t always set a specific driver code. We swapped in a pre-programmed ECM, performed the security relearn, and the misfire vanished instantly. The car ran smoother than it had in years. It’s a classic case where the root cause is electronic, not mechanical, and this module is the definitive fix.
Is Your Vehicle Showing These Symptoms?
- ✔ Check Engine Light (CEL) is on with codes that won’t clear.
- ✔ Common Diagnostic Trouble Codes (DTCs) like P0601 (Internal Control Module Memory Check Sum Error), P0606 (ECM/PCM Processor Fault), or U0100 (Lost Communication With ECM/PCM).
- ✔ Engine cranks but refuses to start.
- ✔ Noticeable drop in fuel efficiency.
- ✔ Rough or erratic engine idling.
- ✔ The vehicle stalls unexpectedly while driving or at a stop.
- ✔ Automatic transmission shifts harshly or at the wrong times.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the ECM: On most compatible vehicles like the Sonic or Cruze, the ECM is typically found in the engine bay, often mounted to the firewall or inner fender. It’s a silver metal box with several large electrical connectors.
- ✔ Disconnect and Remove: Carefully unclip the wiring harness connectors. They usually have a locking tab or lever. Once disconnected, unbolt the module from its mounting bracket and remove it from the vehicle.
- ✔ Install the New Module: Bolt the new, pre-programmed ECM into place. Reconnect the wiring harnesses, ensuring they click securely into place.
- ✔ Reconnect Battery: Reattach the negative battery terminal.
- ✔ Perform Security Relearn: You will need to perform a simple key-cycle security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times. This allows the new ECM to sync with your vehicle’s anti-theft system. Your vehicle will not start until this is completed.
Verified Vehicle Compatibility
This module is a direct replacement for part number 12670335 and is interchangeable with several other part numbers, including 12668866, 12668994, 12643636, and more. It is guaranteed to fit the following models (please verify your specific options):
- Buick Encore: 2013-2016 (1.4L)
- Buick ELR: 2014-2016
- Chevrolet Cruze: 2012-2016 (Gasoline models, including 1.4L)
- Chevrolet Sonic: 2012-2016
- Chevrolet Spark: 2014-2015 (Gasoline model)
- Chevrolet Trax: 2013-2016
- Chevrolet Volt: 2011-2015
- GMC/Chevrolet Vans (Express, Savana): 2016 (4.8L, 6.0L)
- GMC/Chevrolet Trucks (Silverado, Sierra 2500/3500): 2012-2016 (6.0L)
- Chevrolet Suburban 3500: 2016
Do I need to do any programming myself?
Do I need to do any programming myself?
No. We handle all the programming for you before shipment. We flash the module with the latest GM software using your vehicle’s VIN. The only step you may need to perform after installation is a simple security relearn procedure, which requires no special tools.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically add it as a note to the seller during checkout or message us directly with your order number. We cannot ship your part until we receive the VIN.
Is this a brand new part?
This is a high-quality, tested, and verified used OEM part. Each module is thoroughly inspected and then programmed with fresh, vehicle-specific software, ensuring it functions to original factory standards and provides a reliable, long-lasting repair.
Will this fix my car’s specific problem?
This ECM is the solution for a wide range of issues caused by a faulty module. If your vehicle is displaying symptoms like a no-start condition, persistent CEL with codes like P0601, or erratic engine behavior, and your mechanic has diagnosed the ECM as the cause, this part is the correct fix. It is vital to ensure a proper diagnosis has been performed.