Is your Chevrolet HHR or other GM vehicle suffering from perplexing engine issues like stalling, poor fuel economy, or a persistent Check Engine Light? The Electronic Control Module (ECM), the brain of your engine’s operations, is often the culprit. This replacement ECM, corresponding to part number 12638026 and service number 12597125, is your direct-fit, reliable solution. We take the guesswork out of the repair by pre-programming the module to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This ensures seamless integration and restores your vehicle’s original performance and efficiency.
From the Diagnostic Bay
We had a 2009 Chevy HHR come into the shop with a complaint of intermittent stalling at stoplights and a random P0606 (ECM Processor Fault) code. The owner had already replaced the spark plugs and an O2 sensor with no luck. After verifying power and grounds to the ECM were solid, we monitored the data stream and noticed erratic sensor readings just before it would stall. We knew the internal processor was failing. We installed one of these VIN-programmed modules, performed a quick CASE relearn, and the HHR ran perfectly. It’s a classic example of how a failing computer can mimic other component failures, making accurate diagnosis key.
Common Symptoms of a Failing ECM
- ✔ Check Engine Light is on with various, often inconsistent, trouble codes.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Transmission shifting issues or harsh engagement.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Misfire codes that don’t resolve after replacing coils and plugs.
Your Solution: A Programmed 2007-2011 HHR ECM
Replacing an ECM isn’t just about swapping hardware. Modern vehicles require precise software that matches the engine, transmission, and all factory-installed options. Our process simplifies this complex repair. When you order, you provide us with your vehicle’s VIN. Our technicians then use official GM software to load the latest, most stable calibration directly onto the module. This means that when you receive your 2007-2011 HHR ECM, it’s ready to be installed without needing a trip to the dealership for expensive programming. While this unit is a primary fit for the Chevy HHR, its versatile E37 architecture means it’s also the correct computer for a wide range of other GM vehicles, including the Chevrolet Cobalt, Malibu, Silverado 1500, Pontiac G6, Saturn Aura, and more. Please verify your original part number or consult the fitment list to ensure compatibility.
Upon installation, the only remaining step is typically a security relearn procedure and a Crankshaft Variation (CASE) relearn. These procedures can often be performed by a qualified mechanic with a capable scan tool and are necessary to sync the new computer with your vehicle’s anti-theft system and crankshaft position sensor for optimal performance.
Frequently Asked Questions
Do I need to program this ECM?
No. We handle the programming for you before shipment. Simply provide your vehicle’s VIN during or after checkout, and we will flash the module with the correct GM-certified software for your specific vehicle. It will arrive ready for installation.
What is a CASE relearn and is it required?
A CASE (Crankshaft Angle Sensor Error) relearn is a procedure that calibrates the new ECM to the minor variations in your vehicle’s crankshaft position sensor. It is highly recommended after installation to prevent a P0315 trouble code and ensure accurate misfire detection and engine timing. Most professional scan tools can perform this procedure in a few minutes.
How do I find my original part number?
Your original ECM’s part number is printed on a sticker on the module’s case. It will typically be a ‘Service Number’ or ‘SERV. NO.’ followed by a series of digits, such as 12597125 or 12612397. Matching this number is the best way to guarantee compatibility.
Will this fix my car’s problem?
If your vehicle’s issues have been correctly diagnosed as a faulty ECM, this part is the solution. It is crucial to rule out other potential causes, such as wiring problems, sensor failures, or mechanical issues, before replacing the control module.
What happens if I don’t provide my VIN?
Providing your VIN is a critical step. Without it, we cannot program the module, and your order will be delayed. We will contact you to retrieve the VIN to ensure the part you receive functions correctly in your vehicle.