Restore Flawless Shifting to Your Chevrolet HHR
If your 2006-2011 Chevrolet HHR is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’re not just dealing with an annoyance—you’re facing a critical failure that can leave you stranded. As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by a faulty Transmission Control Module (TCM). The TCM is the brain of your automatic transmission, and when it fails, the symptoms can range from poor fuel economy to a complete loss of drivability. This T42 TCM, part number 24256960, is the definitive solution, arriving pre-programmed to your vehicle’s VIN for a true plug-and-play repair.
Case Study: A Tricky Diagnosis
A customer brought in a 2009 HHR with a classic complaint: it would randomly refuse to shift out of 2nd gear, and the check engine light was on. The code was a generic P0700 (Transmission Control System Malfunction). While this code points to a transmission issue, it doesn’t specify the cause. After verifying the fluid level and condition, we checked the wiring harness for damage—a common issue. With everything else checking out, we diagnosed a failing internal processor in the TCM. We installed one of our VIN-programmed modules, and in less than 30 minutes, the HHR was shifting perfectly, with no codes and no need for a costly dealership visit. This is the kind of certain, efficient repair every owner deserves.
Is Your HHR Showing These Transmission Warning Signs?
A failing TCM doesn’t heal itself; it only gets worse. Ignoring these signs can lead to more significant and expensive transmission damage. If you’re experiencing any of the following, your 2006-2011 HHR Transmission Module is likely the culprit:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear) and won’t shift up or down.
- ✔ The Check Engine Light or a dedicated transmission warning light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related faults.
- ✔ A noticeable drop in fuel efficiency or a transmission that seems to be overheating.
- ✔ Complete failure to engage any gear (no forward or reverse).
DIY-Friendly Installation in Under 30 Minutes
One of the biggest advantages of this module is that it bypasses the need for dealership programming. We handle that for you, so you can perform the installation right in your own garage. For the Chevy HHR, the process is especially straightforward.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system’s memory.
- Locate the TCM: On your 2006-2011 HHR, the Transmission Control Module is located in the engine compartment, typically on the driver’s side (LH) near the strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical connectors. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. While the system often resets itself, it’s best practice to use a basic OBD-II scan tool to clear any lingering fault codes from the vehicle’s memory. Start the vehicle and test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles, ensuring OEM-level performance and reliability. While perfect for the 2006-2011 Chevrolet HHR, it also fits many other models. This part is interchangeable with service numbers including 24242391, 24234503, 24252114, and others. Please verify your part number or consult the fitment list below.
Partial Fitment List:
- Chevrolet HHR (2006-2011) – Transmission; (LH engine compartment)
- Chevrolet Cobalt (2006-2010) – Transmission; (LH strut tower)
- Pontiac G5 / G6 (2006-2010) – Transmission; (LH strut tower)
- Saturn Ion (2006-2007) – Transmission; (behind LH strut tower)
- Chevrolet Malibu (2006-2010) – Transmission; (LH frame rail)
- And many more GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
What does a VIN-programmed TCM mean for me?
It means the module arrives ready for installation right out of the box. We flash it with your vehicle’s specific VIN and the latest GM software, so it communicates perfectly with your car’s other computers. This eliminates the need for expensive programming at a dealership, saving you time and money.
Will this fix a P0700 trouble code on my HHR?
A P0700 code is a general fault code indicating the TCM has detected a problem. In many cases where the TCM itself has failed internally, replacing it with this module is the correct fix. However, you should always ensure that wiring and sensors have been checked, as P0700 can also be triggered by other transmission-related issues.
Where is the TCM located on my 2008 HHR?
On the 2006-2011 Chevrolet HHR, the Transmission Control Module is found in the engine bay, mounted on the driver’s side (LH) in the area of the strut tower. It’s a relatively accessible location for a straightforward replacement.
Do I need any special tools for this installation?
No special tools are required. Basic hand tools, like a socket set to remove the mounting bolts and potentially a small screwdriver to help release the connector tabs, are all you should need. An OBD-II scan tool is recommended for clearing codes but not strictly necessary for the part to function.
Is there a core charge or do I need to send my old part back?
No, there is no core charge for this part. You can keep your old module without any hassle or extra fees, simplifying the repair process for you.