Is Your Chevrolet HHR Running Rough?
If you’re experiencing frustrating issues like a persistent check engine light, poor fuel economy, stalling, or a no-start condition, the problem might be the brain of your engine: the Powertrain Control Module (PCM). The PCM is the central computer that manages everything from fuel injection and ignition timing to transmission shifting and emissions control. When it fails, it can cause a wide range of confusing and performance-robbing symptoms. Don’t let a faulty computer keep your reliable HHR off the road. This direct-fit replacement PCM is the solution to restore your vehicle’s performance and dependability.
We had a 2009 HHR come into the shop with an intermittent stalling problem that no one could figure out. The owner had already replaced the crank sensor, cam sensors, and even the fuel pump based on various codes that would pop up. The problem was, the codes were inconsistent. After hooking up our diagnostic scanner and monitoring live data, we noticed the 5-volt reference signal to several sensors would drop out randomly just before the engine would stall. This pointed directly to an internal failure in the PCM. We installed one of our pre-programmed modules, performed the security relearn, and the car ran perfectly. It’s a classic case of the PCM being the root cause, making other components appear faulty.
Symptoms of a Failing GM PCM
- ✔ Persistent Check Engine Light (CEL) with various communication or sensor codes (e.g., U-codes, P0601-P0606).
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Other modules on the vehicle (like the TCM or BCM) cannot communicate with the PCM.
Why Choose Our 2007-2011 HHR PCM?
This isn’t just a replacement part; it’s a complete solution. The biggest hurdle in replacing a modern vehicle’s computer is the complex programming required to make it work with your specific car. We eliminate that problem entirely. When you purchase this module, we use the Vehicle Identification Number (VIN) you provide to flash the unit with the latest, most up-to-date software directly from General Motors. This ensures perfect compatibility and can even resolve underlying drivability issues that were present in the original factory software.
This module is a direct replacement for service number 12635901 and is also compatible with a wide range of other service numbers, including: 12597125, 12612397, 12594750, 12629019, 12635902, and 12611549. While this listing is focused on the 2007-2011 HHR PCM, this versatile computer is also the correct part for dozens of other GM vehicles like the Cobalt, Malibu, G6, Silverado, and more. Please verify the part number or consult our full fitment list to ensure compatibility.
Plug-and-Play Installation
Because we handle the programming, installation is straightforward. Simply disconnect the battery, remove your old PCM, install the new one, and reconnect the battery. In most cases, you will need to perform a security relearn procedure (also known as a CASE relearn or anti-theft relearn) to sync the new computer with your vehicle’s keys and anti-theft system. This procedure is often simple and can be done without special tools, though sometimes a professional scan tool is required. This step is critical for the vehicle to start and run with the new module.
Frequently Asked Questions
Do I need to program this PCM?
No. We handle all the programming for you before we ship the part. Simply provide us with your vehicle’s VIN during or after checkout, and we will flash the module with the correct GM software for your specific vehicle.
Where is the PCM located on my 2007-2011 HHR?
On the Chevrolet HHR, the PCM is typically located in the engine compartment, on the driver’s side, near the rear of the engine bay. It is a silver metal box with several large electrical connectors.
What is a CASE relearn and will I need to do one?
A CASE (Crankshaft Angle Sensor Error) relearn, also known as a crankshaft variation relearn, synchronizes the new PCM with the crankshaft position sensor. Many GM vehicles require this procedure after a PCM replacement to prevent a check engine light. You may also need to perform a security/anti-theft relearn. Both procedures may require a capable bi-directional scan tool.
Is this compatible with other vehicles besides the HHR?
Yes, this PCM is used in a wide variety of GM cars and trucks from this era, including the Chevy Cobalt, Malibu, Silverado 1500, Pontiac G6, Saturn Vue, and more. Please check the detailed fitment list on this page to confirm it is correct for your specific model and engine.
How do I provide my VIN?
You can add your VIN to the notes section during checkout or send it to us in a message after you complete your purchase. We cannot program and ship your module without a valid VIN.