If you’re dealing with the headaches of a failing transmission in your 2006-2011 Chevrolet HHR, you know how frustrating it can be. One minute your car drives fine, the next it’s slamming into gear or won’t shift at all. As a technician with over two decades of experience, I’ve seen this exact scenario countless times. The culprit is often a faulty Transmission Control Module (TCM), the electronic brain that manages your automatic transmission’s every move.
This isn’t just another part; it’s a permanent fix. We offer a direct-replacement T42 TCM, part number 24239224, that arrives at your doorstep pre-programmed to your HHR’s specific Vehicle Identification Number (VIN). This means you can skip the expensive trip to the dealership for programming. It’s a true plug-and-play solution designed to restore the smooth, reliable performance you expect from your vehicle.
Is Your HHR Showing These Transmission Red Flags?
A failing TCM doesn’t always mean a complete transmission failure. Often, it presents as a series of confusing and intermittent electronic symptoms. Here’s what to look for:
- ✔ Harsh, jerky, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle suddenly entering “limp mode,” where it gets stuck in a single gear (usually 2nd or 3rd).
- ✔ An illuminated Check Engine Light or Transmission Warning Light on your dash.
- ✔ Common Diagnostic Trouble Codes (DTCs) stored in the system, such as P0700 (Transmission Control System Malfunction) or various solenoid-specific codes (e.g., P0750-P0758).
- ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
- ✔ Complete loss of communication with the module, preventing the vehicle from starting or shifting out of Park.
From the Diagnostic Bay: The Intermittent Shifting Mystery
A customer brought in their 2009 HHR with a problem that was driving them crazy. The car would shift perfectly for days, then suddenly start banging into gear and throw a P0700 code. They’d already replaced a shift solenoid with no luck. After connecting my scan tool, I noticed the TCM would intermittently drop communication. Heat soak in the engine bay was causing an internal failure in the original module. Instead of a costly transmission rebuild, we installed one of our VIN-programmed TCMs. The problem was solved instantly. This is a classic failure mode for the 2006-2011 HHR TCM, and this part is the definitive fix.
A Straightforward Guide to Your HHR TCM Installation
One of the biggest benefits of this module is how simple it is to install. You don’t need a lift or specialized transmission tools. For the Chevy HHR, the process is quick and can be done in your driveway in under 30 minutes.
- Safety First: Before you begin, disconnect the negative terminal on your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the TCM: On the 2006-2011 HHR, you’ll find the Transmission Control Module in the engine compartment, typically on the left-hand (driver’s) side. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harnesses from the old module. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed TCM into place and securely reconnect the wiring harnesses. Ensure they click into place.
- Final Steps: Reconnect the negative battery terminal. Start the vehicle and let it idle for a few minutes. If you have a basic scan tool, it’s a good practice to clear any lingering fault codes. Take the car for a test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is the correct replacement for the 2006-2011 Chevrolet HHR. It is also a direct fit for a wide range of other General Motors vehicles that use the same module architecture. It is interchangeable with numerous part numbers, including 24252114, 24234503, 24230461, and 24239224.