Is Your Chevrolet HHR Running Rough? The ECM Might Be the Culprit.
If your 2007-2011 Chevrolet HHR is experiencing baffling issues like stalling, poor fuel economy, a persistent Check Engine Light, or erratic shifting, the problem may lie deep within its electronic nervous system: the Engine Control Module (ECM). As the central computer for your vehicle’s powertrain, a failing ECM can cause a cascade of frustrating and hard-to-diagnose symptoms. This isn’t just an inconvenience; it affects your vehicle’s reliability, performance, and safety. Don’t let a faulty computer keep you off the road. We offer a direct, reliable solution with this pre-programmed ECM, designed to restore your HHR to its original factory performance.
From the Diagnostic Bay
We had a 2009 HHR come into the shop with a complaint of intermittent stalling at stoplights and a random P0606 (ECM Processor Fault) code that would come and go. The owner had already replaced the spark plugs, ignition coil pack, and even a MAP sensor with no success. After running a full diagnostic, we monitored the live data stream from the ECM and noticed erratic voltage readings from the 5-volt reference circuit, but only when the engine bay was hot. This pointed to an internal failure in the ECM’s circuit board. Instead of a costly and time-consuming diagnostic rabbit hole, a pre-programmed replacement ECM was the direct fix. After a simple installation and a 10-minute security relearn, the HHR ran perfectly, the code was gone, and the stalling issue was completely resolved. It’s a classic case of how the central computer can create symptoms that mimic other component failures.
Common Symptoms of a Failing 2007-2011 HHR ECM
- ✔ Check Engine Light: The most common sign, often with communication-related codes (U-codes) or internal processor fault codes (P06xx series).
- ✔ Engine Stalling or Misfiring: The engine may stall unexpectedly, run rough, or misfire as the ECM fails to properly manage fuel and spark.
- ✔ Poor Performance & Fuel Economy: A faulty module can’t optimize the engine’s functions, leading to a noticeable drop in power and an increase in fuel consumption.
- ✔ No-Start Condition: In severe cases, the ECM may fail to activate the fuel pump or ignition system, preventing the vehicle from starting at all.
- ✔ Erratic Automatic Transmission Shifting: The ECM works with the Transmission Control Module (TCM) to ensure smooth shifts. A failing ECM can cause harsh or delayed shifting.
- ✔ Communication Issues: Your diagnostic scan tool may be unable to communicate with the module, making diagnosis impossible.
Your Plug-and-Play Solution: Programmed to Your VIN
Replacing an ECM isn’t as simple as swapping out a battery. The module is specific to your vehicle’s unique configuration, including its engine, transmission, and factory options. Our process eliminates the guesswork and the need for expensive dealership programming. When you order, simply provide us with your vehicle’s 17-digit VIN. We will then flash this module with the latest, most up-to-date software directly from GM for your specific vehicle. This ensures perfect compatibility and function right out of the box. This module, service number 12629020, is a direct replacement for a wide range of original service numbers including 12597125, 12612397, 12629019, and more, making it a versatile and reliable fix for many GM vehicles.
Once you receive your programmed module, installation is straightforward. In most HHR models, the ECM is located in the left rear of the engine compartment. After disconnecting the battery, you simply unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. The final step is a simple security relearn procedure (often called Passlock or Passkey), which can be done in your driveway with just the key—no special tools required. This procedure syncs the new ECM with your vehicle’s anti-theft system, allowing it to start.
Frequently Asked Questions
Do I need to have this ECM programmed?
No. We handle all 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 software for your specific HHR.
What is a security relearn procedure?
It’s a simple process that syncs the new ECM with your vehicle’s anti-theft system. It typically involves turning the key to the ‘ON’ position for 10 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. This allows the vehicle to recognize the new module.
Where is the ECM located on my 2007-2011 HHR?
The Engine Control Module on the Chevrolet HHR is typically found in the engine compartment, on the driver’s side, near the firewall or fuse box.
Will this fix my Check Engine Light?
If the Check Engine Light and other symptoms are caused by a faulty ECM, this replacement part is the correct solution. It’s crucial to ensure a proper diagnosis has been performed to rule out other issues like faulty sensors or wiring.
Is this part compatible with other GM models?
Yes, this ECM fits a wide variety of GM vehicles like the Cobalt, Malibu, G6, and Silverado with specific engines. However, this listing is programmed specifically for the 2007-2011 Chevrolet HHR. The programming is key to compatibility.