Restore Smooth, Reliable Shifting to Your Chevrolet HHR
If you’re dealing with the frustrating and unpredictable behavior of a failing transmission in your 2006-2011 Chevy HHR, you’re not alone. Over my 20 years in the shop, I’ve seen countless GM vehicles, including the HHR, come in with symptoms like harsh banging into gear, getting stuck in limp mode, or throwing a P0700 code that just won’t go away. The culprit is often a faulty Transmission Control Module (TCM). This OEM-quality T42 TCM, part number 24239224, is the definitive solution. It arrives expertly pre-programmed to your vehicle’s specific VIN, eliminating the need for expensive dealership visits and making the repair a true plug-and-play process.
As the electronic brain of your automatic transmission, the TCM is responsible for every shift command, torque converter clutch engagement, and line pressure adjustment. When it fails, communication breaks down, leading to poor performance, decreased fuel economy, and potential long-term damage to your transmission. This replacement module restores that critical communication, ensuring your HHR drives as smoothly and efficiently as it did from the factory.
A Technician’s Notebook
I remember a 2009 HHR that came into my bay with a classic complaint: “It shifts fine when it’s cold, but after 20 minutes of driving, it starts slamming into gear and the check engine light comes on.” The owner had already replaced a shift solenoid with no luck. A quick scan showed a P0700 (Transmission Control System Malfunction) and an intermittent solenoid circuit code. Experience told me this wasn’t a mechanical issue. The heat soak was causing a hairline crack on the TCM’s circuit board to expand, breaking the connection. We installed a VIN-programmed 2006-2011 HHR TCM, and the problem was solved instantly. It’s a common failure pattern on these vehicles, and this part is the reliable fix.
Is Your HHR Showing These Transmission Problems?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, erratic, or delayed gear shifts that feel like the transmission is banging or slipping.
- ✔ Vehicle is stuck in “limp mode,” often refusing to shift out of 2nd or 3rd gear.
- ✔ The Check Engine Light or a transmission warning light is illuminated on your dash.
- ✔ Diagnostic Trouble Codes (DTCs) are present, especially P0700, P0750, P0751, P0752, or other solenoid-related codes.
- ✔ A complete loss of shifting ability, where the vehicle won’t go into gear or won’t upshift/downshift.
- ✔ Noticeably worse fuel mileage and a transmission that seems to be running hotter than usual.
A Straightforward Guide to Installation
Replacing the 2006-2011 HHR TCM is a job most DIYers can handle in their own driveway in under 30 minutes. The module is conveniently located and requires no special tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the TCM: On the Chevrolet HHR, the TCM is typically found in the engine compartment, mounted on the left-hand (driver’s side) inner fender or 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, VIN-programmed TCM into place and securely reconnect the electrical connectors. Ensure they click into place.
- Final Steps: Reconnect the negative battery terminal. While our programming handles the critical setup, it’s good practice to use a basic OBD-II scan tool to clear any stored fault codes from the ECU. Start the vehicle and take it for a test drive to confirm smooth operation.
Verified Fitment for Your General Motors Vehicle
This T42 Transmission Control Module is a direct replacement for part number 24239224 and is compatible with a wide range of GM vehicles. While this page focuses on the HHR, it also fits models like the Cobalt, G5, G6, and many others. It is interchangeable with part numbers including 24252114, 24234503, 24230461, 24234274, and more. We guarantee fitment for the following:
- Chevrolet HHR: 2006, 2007, 2008, 2009, 2010, 2011 (Located in LH engine compartment)
- And many other GM cars, trucks, and SUVs from 2006-2014. Please verify your part number or contact us for confirmation.
Frequently Asked Questions
What does “VIN Programmed” mean?
It means we load your vehicle’s unique 17-digit Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This ensures it communicates perfectly with your car’s other computers right out of the box, with no additional programming needed.
Do I need to send my old TCM back?
No, there is no core charge for this part. You can keep or dispose of your old module, making the process faster and more convenient for you.
Will this fix a P0700 code on my HHR?
A P0700 code indicates a general fault in the transmission control system. While this module is a very common cause, you should always ensure other potential issues (like wiring or solenoids) are ruled out. However, if you have erratic shifting along with a P0700, replacing the TCM is the most likely solution.
Is this an OEM part?
This is a high-quality replacement part built to meet or exceed original equipment manufacturer (OEM) specifications for performance and reliability. It comes with a one-year warranty for your peace of mind.
Can I install this 2006-2011 HHR TCM myself?
Absolutely. The installation is straightforward for anyone with basic mechanical skills. Since it’s pre-programmed, you avoid the complexity and cost of a dealership visit, making it an ideal DIY repair.