Restore Peak Performance to Your Cadillac ELR
Is your 2014-2016 Cadillac ELR suffering from baffling electrical gremlins, poor engine performance, or a persistent Check Engine Light? The Engine Control Module (ECM), often called the Powertrain Control Module (PCM), is the central computer of your vehicle. When it starts to fail, it can cause a wide range of frustrating and difficult-to-diagnose problems. From a car that won’t start to erratic behavior on the road, a faulty ECM can bring your sophisticated vehicle to a standstill. This isn’t just an inconvenience; it’s a critical component for your car’s safety, emissions, and fuel economy.
We offer a dependable and straightforward solution. This Engine Control Module, part number 12663405, is a direct-fit replacement for your original unit. The best part? We handle the most critical step for you. Before this module ever leaves our facility, we will program it with the latest GM-certified software specifically for your vehicle’s VIN. This eliminates the need for an expensive trip to the dealership for programming, saving you significant time and money. You get a component that’s ready to install right out of the box, restoring the precise control and reliability you expect from your Cadillac.
From the Diagnostic Bay: The Intermittent No-Start ELR
I remember a 2015 ELR that came into my shop with one of the most frustrating symptoms: an intermittent no-start condition. The owner was at their wit’s end. We’d check it, and it would start fine ten times in a row. They’d take it home, and it would leave them stranded the next morning. We checked the battery, starter, and fuel pump—all were perfect. After hours of tracing wiring diagrams, we noticed the failures only happened after the car had been sitting in the sun. On a hunch, we used a heat gun on the ECM, and sure enough, the no-start condition appeared instantly. The internal circuits were failing under thermal stress. Replacing the ECM with a properly programmed unit like this one solved the problem for good. It’s a classic example of how a failing computer can mimic a dozen other mechanical issues.
Common Signs of a Failing Engine Computer
A failing ECM can manifest in many ways. If you’re experiencing any of the following, your engine’s computer could be the culprit. Look out for these common symptoms and associated Diagnostic Trouble Codes (DTCs):
- ✔ Check Engine Light is on with no obvious cause.
- ✔ Vehicle fails to start or has difficulty starting.
- ✔ Stalling, stuttering, or hesitation during acceleration.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Transmission shifting issues or getting stuck in gear.
- ✔ Communication error codes, such as U0100 (Lost Communication With ECM/PCM).
- ✔ Internal module failure codes like P0601, P0603, or P0606.
A Straightforward Guide to Installation
Installing your new 2014-2016 ELR Engine Control Module is a manageable job for a confident DIYer or a quick task for any professional mechanic. Following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the ECM: On the 2014-2016 ELR, the ECM is found in the left-hand (driver’s side) rear of the engine compartment.
- Disconnect Connectors: Carefully release the locking tabs on the electrical wiring harnesses and gently pull them straight out from the module. Do not force them.
- Remove the Old Module: Unbolt the mounting hardware that secures the old ECM to its bracket. Keep the hardware in a safe place.
- Install the New Module: Mount your new, pre-programmed ECM using the original hardware. Ensure it is seated securely.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click firmly into place. Reconnect the negative battery terminal.
- Final Steps: In some cases, a security relearn or crank position sensor relearn procedure may be required. This can often be done without special tools. Turn the key to the ‘ON’ position for 10-15 minutes, then off, and repeat two more times before starting the engine. Consult your vehicle’s service information for specific procedures.
Verified Vehicle Compatibility
This module is a direct replacement for part number 12663405 and interchanges with several other GM part numbers, including 12668866, 12668994, and 12643636. While this listing focuses on the 2014-2016 ELR Engine Control Module, it also fits a wide array of other GM vehicles. Please verify your part number or contact us with your VIN to confirm compatibility for the following models:
- Buick Encore (2013-2016)
- Cadillac ELR (2014-2016)
- Chevrolet Cruze (2012-2016)
- Chevrolet Express 2500/3500 Van (2016)
- Chevrolet Silverado 2500/3500 Pickup (2012-2016)
- Chevrolet Sonic (2012-2016)
- Chevrolet Spark (2014-2015)
- Chevrolet Suburban 3500 (2016)
- Chevrolet Trax (2013-2016)
- Chevrolet Volt (2011-2015)
- GMC Savana 2500/3500 Van (2016)
- GMC Sierra 2500/3500 Pickup (2012-2016)
- GMC Sierra Denali 2500/3500 (2012-2016)
What is VIN programming and why is it important?
VIN programming is the process of loading your vehicle’s specific software and settings onto the engine control module. This includes information about your engine, transmission, and factory options. It’s critical for ensuring all systems communicate and function correctly. We do this for you before shipping.
Do I need to do anything after I install this part?
In most cases, the module is ready to go. However, some GM vehicles may require a simple security or crankshaft position sensor relearn procedure after installation. This can typically be done without special tools and instructions can be found online or in a service manual.
How do I provide my VIN number?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module without it.
Is this a brand new part?
This is a high-quality, tested, and guaranteed functional replacement part. It is loaded with the latest vehicle-specific software from GM to ensure optimal performance and longevity, providing a reliable and cost-effective alternative to a new dealer part.
Where can I find my original part number?
Your original part number is printed on a sticker directly on your current engine control module. Matching this number is the best way to ensure compatibility.