Is Your Chevrolet Impala Running Rough? The ECM Might Be the Culprit.
If your 2014, 2015, or 2016 Chevrolet Impala is experiencing frustrating issues like a persistent check engine light, poor fuel economy, engine stalling, or a complete no-start condition, a failing Engine Control Module (ECM) is a very likely cause. The ECM is the central computer of your vehicle, responsible for managing everything from fuel injection and ignition timing to transmission shifting and emissions control. When it fails, the symptoms can be widespread and difficult to diagnose, often leading to incorrect and expensive repairs.
This is a genuine, used OEM Engine Control Module, part number 12633555 (interchangeable with 12653998, 12655007, and 12644446), that provides a reliable and cost-effective solution. Unlike a new part from the dealership, this module is sourced from a salvaged vehicle, offering OEM quality without the high price tag. More importantly, we take the hassle out of the replacement process. Simply provide your vehicle’s VIN during checkout, and our technicians will program the module with the latest GM software specific to your car. This means it arrives at your door ready for a straightforward installation, saving you a costly trip to the dealer for programming.
From the Diagnostic Bay
We had a 2015 Chevy Malibu come in that was a real head-scratcher. The customer had already replaced the spark plugs, ignition coils, and even a fuel injector trying to chase down a random misfire and stalling issue. The codes were intermittent and didn’t point to a single component. After hours of checking wiring harnesses and sensors, we hooked up our scope to the injector driver circuits directly at the ECM. We found that the signal for cylinder 3 would periodically drop out completely. It wasn’t a wiring problem; the fault was internal to the ECM itself. We installed one of our VIN-programmed modules, performed the security relearn, and the car ran perfectly. It’s a classic case of how a faulty ECM can mimic other failures, costing the owner time and money on unnecessary parts.
Symptoms of a Failing 2014-2016 Impala ECM
- ✔ Check Engine Light is on with various, often inconsistent, trouble codes.
- ✔ Engine misfires, stumbles, or runs rough.
- ✔ Vehicle stalls unexpectedly while driving or at idle.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Poor acceleration and overall engine performance.
- ✔ Automatic transmission shifting issues or harsh shifts.
A Simple, Programmed Solution
Don’t let a faulty computer keep your car off the road. This module is the ideal fix for your vehicle, providing the reliability of a genuine factory part with the convenience of pre-programming. The process is simple: place your order, provide us with your VIN, and we handle the complex software flashing. This ensures that the module communicates perfectly with all the other systems in your Impala, Acadia, Traverse, Malibu, or other compatible GM vehicle. Please note that while the core engine programming is done, some vehicles may require a simple security or anti-theft relearn procedure after installation, which can often be done without special tools.
This ECM is a direct fit for a wide range of General Motors vehicles. Please verify your part number and consult the detailed fitment list to ensure compatibility with your specific make, model, and engine option.
Frequently Asked Questions
Do I need to get this ECM programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before we ship it. It will arrive with the latest GM software updates installed, ready for installation. This saves you the time, cost, and hassle of a dealership visit.
Is this a new part?
No, this is a used, genuine OEM part that has been carefully removed from a salvaged vehicle. We inspect and test our modules to ensure they are in good working condition before programming and shipping.
What is a ‘security relearn’ and will I need to do one?
A security relearn, or anti-theft relearn, synchronizes the new ECM with your vehicle’s existing anti-theft system and keys. Many GM vehicles require this simple procedure after an ECM replacement. It can typically be performed in your driveway in about 30 minutes and does not require a mechanic’s scan tool. We can provide instructions for this process.
How do I find my vehicle’s VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.
How can I be sure this part will fit my car?
This ECM, part number 12633555, has several interchangeable part numbers. The best way to ensure compatibility is to match the part number on your original module. You can also review the extensive fitment list on this page or contact us with your VIN, and we can verify compatibility for you.