Is Your Cadillac ELR Acting Unpredictable?
If you’re dealing with a frustrating check engine light, poor engine performance from the range extender, or even a no-start condition after the main battery is depleted, a failing Engine Control Module (ECM) is often the culprit. In my 20+ years as a diagnostic technician, I’ve seen how a faulty ECM can cause a cascade of confusing issues, especially in a sophisticated vehicle like the ELR. It’s the brain of your gasoline engine, and when it malfunctions, your car’s reliability is gone.
The Direct Solution: A VIN-Programmed Replacement
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take this genuine GM Engine Control Module and flash it with the latest, most stable software directly from GM, using your vehicle’s specific VIN. This critical step ensures that the module communicates perfectly with your ELR’s other systems, like the transmission, hybrid controller, and anti-lock brakes, right out of the box. You get a reliable repair without the time and expense of a dealership programming appointment.
Expert Pro Tip: Check Your Connections First
Before condemning your old ECM, take a moment to inspect the main electrical connectors. Over time, vibration and moisture can lead to corrosion on the pins. I’ve seen cases where simply cleaning the terminals with a contact cleaner and a small brush restored communication and fixed the issue. It’s a five-minute check that could save you a lot of time and money. If the pins are clean and tight, and the problem persists, the ECM itself is the likely cause.
Common Symptoms of a Failing 2014-2016 ELR Engine Control Module
A bad ECM can manifest in several ways. If you’re experiencing any of the following, this module is the solution you need:
- ✔ Persistent Check Engine Light (CEL) with codes related to processor faults (e.g., P0601, P0606) or communication errors.
- ✔ The gasoline range-extender engine fails to start or runs rough.
- ✔ Unexplained stalling or hesitation.
- ✔ Decreased fuel economy and performance.
- ✔ Seemingly unrelated error messages on the dash due to network communication failures.
Plug-and-Play Installation: No Dealer Visit Required
We’ve done the hard part for you. The VIN-specific programming means you can perform the installation yourself and get your ELR back to perfect working order. Here’s a general guide:
- Safety First: Disconnect the negative terminal from your 12-volt accessory battery.
- Locate the ECM: On the 2014-2016 ELR, the Engine Control Module is located in the left-hand (driver’s side) rear of the engine compartment.
- Disconnect Connectors: Carefully release the locking tabs and unplug the main electrical harnesses from the old module.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- Install the New Module: Mount your new, pre-programmed ECM and securely reconnect the electrical harnesses. You should hear a ‘click’ as they lock in place.
- Reconnect Battery: Reattach the negative battery terminal. The vehicle may need to complete a few drive cycles to relearn all parameters, but the core programming is already done.
Guaranteed Compatibility
This module, part number 12668991, is a direct replacement for a wide range of GM vehicles and supersedes several older part numbers. It is guaranteed to fit and function correctly if your vehicle is on the list below and your original part number matches one of the following:
Replaces Part Numbers: 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, 12692200
This part will fit these makes and models with these options: ELR 14-16, VOLT 11-15, CRUZE 12-16, SONIC 12-16, TRAX 13-16, ENCORE 13-16, SPARK 14-15, SILVERADO/SIERRA 2500/3500 12-16 (6.0L), EXPRESS/SAVANA VANS 16 (4.8L, 6.0L), and SUBURBAN 3500 16. Please verify your specific model and options in the fitment chart to ensure a perfect match.