Is Your HHR’s Transmission Acting Up?
If you’re driving a 2006-2011 Chevrolet HHR, you know it’s a versatile and reliable vehicle. However, when the transmission starts to act erratically, it can be a source of major frustration and concern. Abrupt, harsh shifts, a sudden refusal to shift gears, or a dashboard lit up with warning lights are all classic signs that your Transmission Control Module (TCM) may be failing. This component is the electronic brain of your automatic transmission, and when it malfunctions, it can sideline your vehicle. This pre-programmed T42 TCM is the definitive solution to restore your HHR’s smooth, predictable performance.
From the Diagnostic Bay
We recently had a customer with a 2009 HHR come into the shop, completely fed up. The car was stuck in what felt like third gear (limp mode) and the check engine light was on. He was worried about a catastrophic transmission failure and a massive repair bill. After a quick scan, we pulled code P0700, a general transmission fault. A deeper dive pointed to internal TCM communication errors. Instead of a costly transmission rebuild, we installed one of these VIN-programmed T42 modules. In under an hour, the codes were cleared, the car was shifting perfectly through all gears, and the customer drove away with a reliable vehicle and significant savings.
Symptoms of a Failing HHR Transmission Control Module
A faulty TCM can manifest in several ways, often mimicking more severe mechanical transmission problems. Before you assume the worst, check if your vehicle is displaying any of these common symptoms. A failing module is often the root cause.
- ✔ Harsh or Erratic Shifting: Your HHR may slam into gear, hesitate between shifts, or shift at the wrong RPMs.
- ✔ Stuck in Gear / Limp Mode: The transmission may refuse to shift out of a single gear (often 2nd or 3rd) to prevent further damage.
- ✔ Warning Lights: The Check Engine Light or a specific transmission warning light will illuminate on your dashboard.
- ✔ Diagnostic Trouble Codes (DTCs): You may find codes such as P0700, P0750, or other solenoid-related faults when using a scan tool.
- ✔ Delayed Engagement: A noticeable delay when shifting from Park into Drive or Reverse.
- ✔ Poor Fuel Economy: Inefficient shifting and torque converter lock-up issues can lead to a sudden drop in your vehicle’s MPG.
- ✔ No Communication: In severe cases, a scan tool may be unable to communicate with the TCM at all.
The Direct-Fit, Programmed Solution
This isn’t just a replacement part; it’s a complete, ready-to-install solution for your vehicle. The biggest hurdle in replacing modern electronic modules is the need for expensive dealership programming. We eliminate that step entirely. By providing us with your vehicle’s VIN during checkout, we can program the module with the latest GM-certified software specific to your 2006-2011 HHR. This ensures that once installed, the module communicates seamlessly with your vehicle’s engine computer (ECU) and other systems for optimal shift strategy, fuel efficiency, and performance.
Built to strict OEM specifications, this module directly replaces service numbers 24242391, 24234503, 24252114, and 24240400, among others. It restores the critical functions of your 4-speed automatic transmission, including managing hydraulic line pressure, controlling shift solenoids, and regulating the torque converter clutch. The result is a transmission that operates as it did from the factory.
Easy Installation for DIYers and Professionals
Replacing the TCM on your HHR is a straightforward job that can typically be completed in your own driveway. On most HHR models, the module is conveniently located in the engine compartment on the driver’s side, near the strut tower or under the air cleaner box. Simply disconnect the negative battery terminal, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Once connected, re-attach the battery terminal. The pre-programming means your vehicle will start and run correctly immediately. We recommend clearing any old DTCs with a basic scan tool after installation to ensure a clean slate for the new module.
Does this module require additional programming at a dealership?
No. This Transmission Control Module is delivered to you fully pre-programmed to your vehicle’s specific VIN. This makes it a true plug-and-play solution, saving you the time, cost, and hassle of a dealership visit.
Is this part difficult to install on my 2006-2011 HHR?
Installation is straightforward for anyone with basic mechanical skills. The TCM is located in the engine compartment (typically on the LH side) and can be swapped out with simple hand tools in under 30 minutes. Just be sure to disconnect the battery before starting.
What happens if I don’t replace a failing TCM?
Ignoring a failing TCM can lead to more severe issues. Continued erratic shifting can cause premature wear on mechanical components like clutches and bands, potentially leading to a complete transmission failure and a much more expensive repair.
How do I know this is the correct part for my vehicle?
This module is the correct fit for 2006-2011 Chevrolet HHR models with a 4-speed automatic transmission. It is also a direct replacement for numerous GM part numbers, including 24240400. Providing your VIN at checkout ensures we program it perfectly for your specific vehicle configuration.
Is there a core charge for this part?
No, there is no core charge required for this module. You can keep your old part without the hassle of returning it, making the replacement process even simpler.