Restore Your Cadillac’s Core Performance
If you’re dealing with frustrating issues like your 2014-2016 Cadillac ELR not starting, stalling unexpectedly, or showing a persistent Check Engine Light, a failing Engine Control Module (ECM) is a very likely culprit. As the brain of your vehicle’s advanced powertrain, when the ECM falters, it can cause a cascade of problems that are often difficult to diagnose. From my 20+ years in the bay, I’ve seen how a faulty ECM can mimic other issues, leading to wasted time and money on unnecessary repairs. This module is the direct, reliable solution to get your sophisticated vehicle operating as it should.
This isn’t just a replacement part; it’s a complete service. We take the guesswork and high dealership costs out of the equation. Before we ship, this 2014-2016 ELR Engine Control Module is professionally programmed with the latest GM software updates, specifically matched to your vehicle’s VIN. This critical step ensures that once installed, the module communicates perfectly with your car’s other systems, restoring fuel efficiency, ignition timing, and transmission shifting to factory specifications.
A Technician’s Notebook: The Ghost in the Machine
I remember a 2015 Chevy Volt—which shares a similar powertrain architecture with the ELR—that came into the shop with a truly baffling set of symptoms. The owner complained of intermittent power loss and the vehicle randomly refusing to switch between electric and gasoline modes. There were no consistent trouble codes, just a few random communication errors (U-codes) that would appear and disappear. We checked the battery, the hybrid generator, and all the wiring harnesses, but everything tested fine. After days of diagnostics, I focused on the ECM. On the surface, it seemed okay, but by monitoring live data streams during a long test drive, I saw the processor voltage drop erratically for milliseconds at a time—just long enough to disrupt commands but not long enough to set a hard fault code. Replacing the ECM with a properly programmed unit solved everything instantly. It’s a classic example of how a failing 2014-2016 ELR Engine Control Module can create ghost-like problems that defy typical diagnostic procedures.
Is Your Vehicle Showing These Symptoms?
- ✔ Check Engine Light is on with codes like P0601, P0606 (Internal Processor Failure), or various U-codes (Loss of Communication).
- ✔ The engine cranks but refuses to start.
- ✔ Poor fuel economy and noticeable loss of power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent stalling or rough idling.
- ✔ Issues with the vehicle’s hybrid or charging systems.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your 12V battery and secure it away from the post to prevent accidental reconnection.
- ✔ Locate the ECM: On the 2014-2016 ELR, the Engine Control Module is typically found in the left-hand rear of the engine compartment. Consult your vehicle’s service manual for the exact location.
- ✔ Disconnect Connectors: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Do not force them. Inspect the connectors for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the mounting hardware holding the old ECM in place and remove it from the vehicle.
- ✔ Install the New Module: Mount your new, pre-programmed ECM in the same location and secure it with the original hardware.
- ✔ Reconnect Everything: Plug the electrical connectors firmly back into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Perform Relearn (If Needed): While the module is pre-programmed, some vehicles may require a simple security or crankshaft position sensor relearn procedure. This can often be done without special tools. Check your service manual for specific instructions.
Verified Vehicle Compatibility
This ECM is a direct replacement for part number 12670335 and also interchanges with part numbers 12668866, 12668994, 12643636, 12663405, 22819494, and 12692200. It is guaranteed to fit the following models, but please provide your VIN to ensure perfect programming for your specific application.
- Cadillac ELR: 2014-2016 (Gasoline, LH rear engine compartment)
- Chevrolet Cruze: 2012-2016 (See fitment list for specific IDs/VINs)
- Chevrolet Sonic: 2012-2016 (See fitment list for specific IDs/engines)
- Chevrolet Trax: 2013-2016
- Chevrolet Volt: 2011-2015 (Gasoline, LH rear engine compartment)
- Chevrolet Spark: 2014-2015 (Gasoline model)
- Buick Encore: 2013-2016 (1.4L, see fitment list for specific IDs/VINs)
- Chevy Express / GMC Savana Vans (2500/3500): 2016 (4.8L, 6.0L)
- Chevy Silverado / GMC Sierra Trucks (2500/3500): 2012-2016 (6.0L)
- And more, see full list in product details.
Choosing this pre-programmed 2014-2016 ELR Engine Control Module is the most efficient way to solve complex electronic issues and restore your vehicle’s drivability and performance. Don’t let a faulty computer keep you off the road.
Frequently Asked Questions
Do I need to do anything after I install this ECM?
This module is delivered fully programmed to your VIN. However, on some GM vehicles, a simple security relearn or crankshaft position variation relearn may be necessary. These procedures typically do not require a dealer-level scan tool and instructions can be found online or in a service manual.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We will provide clear instructions on how to do this. We cannot program and ship the module without it.
Is this a new or used part?
This is a high-quality, tested, and verified recycled OEM part. Each unit is inspected for integrity before being programmed with the latest GM software for your specific vehicle, ensuring OEM-level function and reliability.
Will this fix my Check Engine Light?
If the Check Engine Light is caused by an internal failure of the ECM (common codes P0601-P0606), then yes, this part will resolve the issue. It’s crucial to ensure your vehicle’s problem has been correctly diagnosed as a faulty module, as this part will not fix other mechanical or electrical issues.
What if I have a different part number on my old module?
This module is a direct replacement for several part numbers, including 12668866, 12668994, and 12643636. As long as your vehicle is on our compatibility list, this module will function correctly once programmed to your VIN.