Restore Your Vehicle’s Core Performance and Reliability
Is your Chevrolet Spark, Cruze, Sonic, or other GM vehicle experiencing frustrating issues like stalling, erratic idling, a persistent Check Engine Light, or a complete no-start condition? As a technician with over two decades of diagnostic experience, I’ve seen firsthand how a failing Engine Control Module (ECM) can disrupt your daily life. The ECM is the brain of your engine, managing everything from fuel delivery and ignition timing to emissions and transmission shifting. When it fails, the symptoms can be confusing and costly to diagnose.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take a genuine GM ECM, part number 12643636, and professionally program it with the very latest GM-certified software specific to your vehicle’s VIN. This critical step ensures all factory performance parameters and operational logic are perfectly matched to your car, eliminating the need for an expensive trip to the dealership for programming. You receive a module that is truly plug-and-play, designed to resolve common electronic issues and restore your vehicle’s original drivability.
Case Study: A Tricky Diagnosis
A customer brought in a 2014 Chevy Sonic that would randomly stall at traffic lights. They had already replaced the battery and alternator with no luck. The scan tool showed a generic U0100 ‘Lost Communication with ECM’ code, but it was intermittent. After checking the wiring harness and grounds—a common culprit—we suspected an internal ECM fault. These hairline cracks on the circuit board, caused by thousands of heat cycles, are often invisible. We installed one of our pre-programmed ECMs, and the problem was solved instantly. The customer saved hundreds on further diagnostic time and avoided a dealership tow and programming fee.
Signs Your Engine Control Module Is Failing
A faulty ECM can manifest in various ways. If you’re noticing any of the following, your engine computer may be the root cause:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or U0100 (Lost Communication).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Rough idling, stalling, or engine hesitation during acceleration.
- ✔ Automatic transmission shifting issues or harsh engagement.
- ✔ Seeming loss of power despite no other mechanical problems.
Your Straightforward ECM Installation Guide
Replacing the ECM is a manageable job for a DIY enthusiast. Follow these general steps for a successful installation:
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to ensure all systems are powered down.
- Locate the ECM: On most compatible vehicles, the ECM is found in the engine bay, often on the firewall or near the battery. Consult a repair manual for your specific model’s location.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old module. These usually have a locking tab that needs to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed ECM into place.
- Reconnect Everything: Firmly re-seat the wiring harness connectors until they click into place. Reconnect the negative battery terminal.
- Final Step: Some vehicles require a security or crankshaft position sensor relearn procedure after installation. This can often be done with a capable scan tool or by following a specific vehicle procedure (e.g., turning the key to ‘On’ for 10-15 minutes).
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of General Motors vehicles. Please match your part number (12643636) or vehicle from the list below. After purchase, you must provide your VIN so we can ensure perfect programming.
Compatible Part Numbers: 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, 12692200
- Encore: 2013-2016 (1.4L)
Cadillac:
- ELR: 2014-2016
Chevrolet:
- Cruze: 2012-2016 (Gasoline models, including 1.4L)
- Express 2500/3500 Van: 2016 (4.8L, 6.0L)
- Silverado 2500/3500 Pickup: 2012-2016 (6.0L)
- Sonic: 2012-2016
- Spark: 2014-2015 (Gasoline model)
- Suburban 3500: 2016
- Trax: 2013-2016
- Volt: 2011-2015
GMC:
- Savana 2500/3500 Van: 2016 (4.8L, 6.0L)
- Sierra 2500/3500 Pickup (including Denali): 2012-2016 (6.0L)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. It allows us to program the module with the exact software calibration and security information for your specific vehicle, including its engine, transmission, and factory options. This ensures seamless integration and proper function.
Is this a simple plug-and-play installation?
Yes, for most vehicles. Because we pre-program the module to your VIN, you will not need to take it to a dealership for programming. In some cases, a simple ‘relearn’ procedure for the security system or crankshaft sensor might be necessary, which can often be done without special tools.
Will this fix my specific problem?
This module is a direct solution for a failed ECM. If your vehicle has been properly diagnosed with a faulty engine computer (e.g., with codes like P0601), this part will resolve the issue. It will not fix problems related to other faulty sensors or mechanical components.
Do I need to send my old module back?
No core charge is required for this part. You can keep or responsibly recycle your old module without needing to send it back to us.
What if my part number is slightly different?
This module replaces several part numbers, including 12668866, 12668994, and others listed in the compatibility section. As long as your vehicle and original part number are on our list, this module will work correctly once programmed.