Programmed 2017 Terrain ECM Engine Control Module 12666070

Restore Peak Performance to Your 2017 GMC Terrain

Is your 2017 GMC Terrain acting up? Experiencing frustrating issues like random stalling, a persistent check engine light, poor fuel economy, or a complete no-start condition? As a technician with over two decades of experience under the hood, I’ve seen these exact symptoms countless times. Often, the root cause isn’t a mechanical failure but a problem with the vehicle’s central computer—the Engine Control Module (ECM). This isn’t just a part; it’s the brain of your engine, and when it falters, the entire vehicle suffers.

This isn’t just a replacement part; it’s a complete solution. We provide a genuine OEM-spec ECM, part number 12666070, that arrives at your doorstep fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We install the latest GM-certified software, ensuring all factory protocols for fuel delivery, ignition timing, and emissions are perfectly calibrated. This eliminates the need for an expensive trip to the dealership for programming, saving you both time and money. By installing our professionally prepared 2017 Terrain ECM, you’re not just fixing a problem—you’re restoring your vehicle’s original reliability and efficiency.

Common Signs of a Failing Engine Computer

If your vehicle’s computer is on its way out, it will usually let you know. Keep an eye out for these common indicators. A failing ECM can be the hidden cause behind one or more of these issues:

• ✔ Check Engine Light is illuminated with codes like P0601, P0606, or other communication faults.
• ✔ The engine cranks but refuses to start.
• ✔ Unexplained drops in fuel mileage and poor engine performance.
• ✔ The vehicle stalls unexpectedly while driving or idling.
• ✔ Automatic transmission shifts harshly or erratically.
• ✔ Communication errors with diagnostic scan tools.

A Straightforward Guide to Installation

Installing your new 2017 Terrain ECM is a manageable job for a confident DIYer or any professional mechanic. Following these steps ensures a safe and successful replacement.

1. Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow all system capacitors to discharge.
2. Locate the Module: On the 2017 Terrain and Equinox, the ECM is typically found in the left-hand (driver’s side) of the engine compartment. On other models, it may be behind the fan shroud. Refer to your vehicle’s service manual if unsure.
3. Disconnect Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the old ECM. Never force them. Inspect connectors for any corrosion or damage.
4. Remove the Old ECM: Unbolt the mounting hardware that secures the old computer to its bracket or the vehicle body. Set the old module aside.
5. Install the New ECM: Mount your new, pre-programmed ECM in the same location and secure it with the original hardware. Do not overtighten the bolts.
6. Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
7. Final Steps: Some vehicles may require a security relearn or crankshaft position sensor relearn procedure, which 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. This allows other modules to recognize the new ECM.

Verified Vehicle Compatibility

This module is a direct-fit replacement for several GM vehicles and interchanges with part numbers 12667002 and 12667189. Please provide your VIN upon purchase to guarantee perfect programming. This part fits the following models:

• ✔ 2017 GMC Terrain – Electronic Control Module; (LH engine compartment)
• ✔ 2017 Chevrolet Equinox – Electronic Control Module; (LH engine compartment)
• ✔ 2017-2019 Chevrolet Impala – Electronic Control Module
• ✔ 2017 Buick Regal – Electronic Control Module; (LH engine compartment)
• ✔ 2017 Buick Verano – Electronic Control Module
• ✔ 2017 GMC Acadia – Electronic Control Module; VIN J (11th digit, Limited), (behind fan shroud)
• ✔ 2017 Buick Enclave – Electronic Control Module; (behind fan shroud)
• ✔ 2017 Chevrolet Traverse – Electronic Control Module; (behind fan shroud)
• ✔ 2017-2019 Cadillac XTS – Electronic Control Module; (3.6L), VIN 3 (8th digit, opt LFX)
• ✔ 2017 Chevrolet Caprice – Electronic Control Module; 3.6L

Frequently Asked Questions