Is your Chevrolet Impala or other GM vehicle suddenly stalling, running rough, or refusing to start? A persistent Check Engine Light and a host of confusing diagnostic codes can often point to one critical component: a failing Engine Control Module (ECM). As a technician with over two decades of experience, I’ve seen firsthand how a faulty ECM can cripple a perfectly good engine. This isn’t just an inconvenience; it’s a matter of reliability and safety. You need a solution that works right out of the box, and that’s exactly what we provide.
This is a direct-fit replacement Engine Control Module, part number 12667002, for a wide range of GM vehicles. The most significant benefit we offer is our professional programming service. Before this module ships, we will flash it with the latest GM-certified software updates, specifically matched to your vehicle’s VIN. This crucial step eliminates the need for an expensive trip to the dealership for programming, making this a straightforward repair for both professional mechanics and determined DIYers. Simply provide your VIN at checkout, and we’ll handle the complex part so you can focus on the installation.
Common Signs of a Failing Engine Computer
If you’re experiencing any of the following issues, a failing ECM is a likely culprit. I’ve diagnosed hundreds of cars with these exact symptoms, which were resolved with a properly programmed module.
- ✔ Check Engine Light is illuminated with codes like P0601, P0606, or other communication errors.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially after the vehicle warms up.
- ✔ Noticeable decrease in fuel economy and engine performance.
- ✔ Automatic transmission shifting erratically or harshly.
- ✔ Communication issues with diagnostic scan tools.
Case Study: A Tricky Diagnosis
I remember a 2018 Impala that came into my shop with an intermittent no-start condition that was driving the owner crazy. It would start fine for a week, then suddenly refuse to crank for an hour. There were no consistent trouble codes, just a generic U0100 ‘Lost Communication with ECM’ that would appear and disappear. After checking all the wiring and power feeds to the module, we found no issues. On a hunch, we connected a scope and saw the ECM’s internal voltage regulator was dropping out randomly when it got hot. A new, properly programmed 2017-2020 Impala ECM like this one solved the problem permanently. It’s often these subtle internal failures that cause the most headaches.
A Straightforward Guide to Installation
Installing your pre-programmed 2017-2020 Impala ECM is a manageable job that can be done with basic hand tools. Since we’ve handled the programming, you won’t need any special electronic equipment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow all systems to discharge.
- Locate the ECM: On many of these vehicles, the ECM is found in the engine compartment, often near the fan shroud or on the driver’s side. Consult a vehicle-specific repair guide if you are unsure.
- Disconnect Connectors: Carefully release the locking tabs on the electrical connectors and pull them straight out. Never force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you will need it for the new module.
- Install the New Module: Mount the new ECM securely onto the bracket and reconnect the electrical harnesses. Ensure they click into place.
- Reconnect Battery: Reattach the negative battery terminal. The vehicle may need to complete a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12667002, 12666070, and 12667189. It is guaranteed to fit the following models and options. Please confirm your vehicle is on this list before ordering.
- ✔ 2017-2019 Chevrolet Impala
- ✔ 2017 Chevrolet Caprice (3.6L)
- ✔ 2017 Chevrolet Traverse
- ✔ 2017 Chevrolet Equinox
- ✔ 2017-2019 Cadillac XTS (3.6L, 8th digit of VIN is ‘3’)
- ✔ 2017 GMC Acadia (Limited, 11th digit of VIN is ‘J’)
- ✔ 2017 GMC Terrain
- ✔ 2017 Buick Enclave
- ✔ 2017 Buick Regal
- ✔ 2017 Buick Verano
Frequently Asked Questions
Do I need to do anything after installing this ECM?
Because we program the module to your VIN, it is ready for installation. In some cases, a security relearn procedure or Crankshaft Position Variation (CASE) relearn may be required, which can often be done without special tools. Instructions are widely available online or in service manuals.
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 cannot program and ship your module without it. Please double-check the VIN for accuracy.
Is this a new or used part?
This is a high-quality, tested, and verified recycled part that has been professionally prepared for service. Each unit is inspected and programmed with the latest software to ensure reliability and performance.
Will this fix my car’s problem?
This ECM will correct issues directly caused by a faulty engine computer. However, it’s crucial to ensure your vehicle has been properly diagnosed. This part will not fix problems related to bad sensors, wiring, or other mechanical failures.
What is your warranty policy?
We stand behind our work. All of our programmed modules come with a comprehensive warranty that covers any defects in the module or programming. Please see our warranty page for full details.