Is Your Vehicle’s Brain Failing?
The Engine Control Module (ECM), often called the Powertrain Control Module (PCM), is the central computer of your vehicle. It’s responsible for managing everything from fuel injection and ignition timing to emissions systems and transmission shifting. When it starts to fail, it can cause a cascade of confusing and frustrating problems that can be difficult to diagnose. If your Cadillac ELR, Chevy Cruze, or other compatible GM vehicle is running poorly, stalling, or has an illuminated Check Engine Light that won’t go away, a faulty ECM could be the culprit.
Symptoms of a Failing Engine Control Module
A failing ECM can manifest in numerous ways. Pay close attention if your vehicle is experiencing any of the following issues, as they are strong indicators that your engine’s computer needs attention:
- ✔ Persistent Check Engine Light (CEL) on your dashboard.
- ✔ Engine stalling, stuttering, or misfiring unexpectedly.
- ✔ Noticeable decrease in fuel economy.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Poor engine performance, including rough idling and hesitation during acceleration.
- ✔ Transmission shifting problems or getting stuck in gear.
- ✔ Unexplained error codes stored in the system, even after clearing them.
- ✔ Communication errors with diagnostic scan tools.
From the Diagnostic Bay
We once had a 2014 Chevy Sonic come into the shop that was driving the owner crazy. It had a persistent misfire on cylinder 3. The owner had already replaced the spark plug, ignition coil, and fuel injector, but the problem remained. A compression test was good, and wiring checks showed no obvious faults. After hours of diagnostics, we finally traced the issue back to the ECM itself. The internal driver circuit for the #3 injector was failing intermittently. A new, pre-programmed ECM like this one solved the problem in minutes. This highlights how a faulty module can mimic other component failures, costing you time and money on unnecessary parts.
The Plug-and-Play Solution: Your Pre-Programmed 2014-2016 ELR Engine Module
Don’t let a faulty computer keep your vehicle off the road. This Engine Control Module, part number 12670335, is the definitive solution for a wide range of GM vehicles. The most significant benefit we offer is our complimentary VIN programming service. When you purchase from us, you provide your vehicle’s VIN, and we flash the module with the latest, most stable software updates directly from GM. This ensures that the computer is perfectly matched to your vehicle’s specific configuration, including its engine, transmission, and factory options.
This critical programming step means your new ECM arrives ready for a straightforward installation. There’s no need for an expensive trip to the dealership for programming or complex procedures with specialized tools. It’s designed to be a direct-fit, plug-and-play replacement, restoring your vehicle’s performance, reliability, and efficiency right out of the box.
Broad Compatibility and Guaranteed Fitment
This versatile ECM is compatible with an extensive list of General Motors vehicles, not just the 2014-2016 Cadillac ELR. It serves as a direct replacement for multiple part numbers, including 12668866, 12668994, 12643636, and more. It is a common component in popular models like the Chevy Cruze, Sonic, Trax, Spark, Volt, and even heavy-duty trucks like the Silverado 2500/3500 and Express/Savana vans. Please verify your part number and consult the detailed fitment list to ensure this is the correct module for your specific vehicle.
Installation Guide
Installing your new ECM is a manageable task for a confident DIYer. Always follow proper safety procedures.
- Disconnect the Battery: Before starting, disconnect the negative terminal of your vehicle’s battery to prevent electrical shorts.
- Locate the ECM: The location varies by model. On the ELR and Volt, it’s in the left-hand rear of the engine compartment. On Silverado trucks, it’s typically on the left-hand front side. Consult a service manual for your specific vehicle.
- Disconnect Connectors: Carefully unplug the wiring harness connectors from the old module. There are usually release tabs that need to be pressed or lifted.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- Install the New Module: Mount the new, pre-programmed ECM in place and securely tighten the bolts. Reconnect the wiring harnesses, ensuring they click into place.
- Reconnect the Battery: Reattach the negative battery terminal. Your vehicle is now ready to start. Some vehicles may require a security relearn procedure, which can often be done without special tools.
Frequently Asked Questions
Do I need to get this ECM programmed by a dealer?
No. We handle all the programming for you before we ship the part. Simply provide us with your vehicle’s VIN during checkout, and the module will arrive ready to install.
What is a VIN and where can I find it?
The VIN (Vehicle Identification Number) is a unique 17-digit code for your car. You can find it on your vehicle’s registration, insurance card, or on a small plate on the driver’s side dashboard visible through the windshield.
Is this a direct replacement for my original part?
Yes, this module is a direct replacement for the part numbers listed, including 12670335, 12668866, 12668994, and others. It is designed to meet or exceed original equipment specifications for fit and function.
Will this fix my check engine light?
If the check engine light and associated running issues are caused by a faulty ECM, then replacing it with this pre-programmed unit will resolve the problem. It’s crucial to ensure the ECM is the root cause of your vehicle’s issues.
What happens if I don’t provide my VIN?
Providing your VIN is essential for the programming service. We cannot ship the module until we receive your VIN, as the programming ensures the part will function correctly with your specific vehicle.