Is Your 2006-2011 Chevrolet HHR Shifting Erratically?
If you’re experiencing harsh shifts, delayed gear engagement, or your HHR is stuck in limp mode, a failing Transmission Control Module (TCM) is the most likely culprit. The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change and ensuring smooth, efficient operation. When it begins to fail, it can cause a cascade of frustrating and potentially damaging issues, from poor fuel economy to a complete inability to shift gears. This VIN-programmed T42 TCM, part number 24240449, is the definitive solution to restore your vehicle’s transmission performance to factory standards.
From the Diagnostic Bay
We had a 2009 Chevy HHR come into the shop with a persistent P0752 code (Shift Solenoid ‘A’ Stuck On). The owner had already replaced the solenoid twice at another shop, but the check engine light and harsh 1-2 shift kept returning. After confirming the solenoid’s wiring and resistance were within spec, we suspected the driver circuit inside the TCM. Instead of another costly and incorrect repair, we installed one of our VIN-programmed T42 modules. After a quick 20-minute installation and clearing the codes, the HHR shifted perfectly. It’s a classic case where the problem wasn’t the component being commanded, but the commander itself—the TCM.
Common Symptoms of a Failing HHR Transmission Control Module
- ✔ Harsh, erratic, or delayed gear shifting that makes driving uncomfortable.
- ✔ Vehicle gets stuck in a single gear (often called ‘limp mode’) to prevent further damage.
- ✔ The check engine light or transmission warning light is illuminated on your dashboard.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, P0755, or other solenoid-related faults are present.
- ✔ A noticeable decrease in fuel efficiency as the transmission operates incorrectly.
- ✔ Complete loss of communication with the module, leading to a no-shift condition.
The Plug-and-Play Solution: Programmed For Your Vehicle
Dealerships and many auto part stores will sell you a blank module that requires expensive programming equipment and a subscription to GM’s software. Our process eliminates that hassle and cost. We pre-program this T42 TCM directly to your HHR’s unique Vehicle Identification Number (VIN) before it ships. This ensures that all the correct software and calibrations are loaded for your specific vehicle configuration. The result is a true plug-and-play component. Simply install it, connect the harnesses, and you’re ready to drive. No extra trips to the dealer, no additional programming fees.
Installation is Simpler Than You Think
For the 2006-2011 Chevrolet HHR, the TCM is conveniently located in the engine compartment, typically on the driver’s side near the strut tower or under the air cleaner box. The replacement process is straightforward for a DIY mechanic with basic tools.
- Safety First: Always disconnect the negative battery terminal before beginning work.
- Locate the TCM: Identify the module in your HHR’s engine bay. It will have several large electrical connectors attached.
- Disconnect and Remove: Carefully unplug the wiring harnesses. Be gentle with the locking tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the wiring harnesses.
- Final Steps: Reconnect the battery. It’s recommended to use a basic OBD2 scan tool to clear any stored transmission codes. Start the vehicle and take it for a test drive to confirm smooth shifting has been restored.
OEM-Quality and Broad GM Compatibility
This module is built to meet or exceed original equipment manufacturer standards for performance and longevity. While it is the perfect fit for your 2006-2011 HHR, this versatile T42 TCM is also the correct service part for a massive range of other General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. It directly interchanges with numerous part numbers, including 24252114, 24234503, 24240400, and 24256960, making it a reliable choice for repairing vehicles from a Chevrolet Silverado or Impala to a GMC Sierra or Saturn Vue. Every module is backed by our one-year warranty for your peace of mind.
Frequently Asked Questions
Will this TCM fit my 2008 Chevrolet HHR?
Yes, this Transmission Control Module is a direct-fit replacement for all 2006, 2007, 2008, 2009, 2010, and 2011 Chevrolet HHR models equipped with an automatic transmission.
What does ‘VIN Programmed’ mean?
It means we load the module with your vehicle’s specific software using your VIN before we ship it. This makes the part ready for installation right out of the box, with no need for additional programming at a dealership, saving you time and money.
Do I need to send my old TCM back?
No, there is no core charge for this part. You can keep your old module or dispose of it responsibly without any need to return it to us.
Is any special tool required for installation?
No special tools are required. Basic hand tools like a socket set and ratchet are all that’s needed to unbolt the old module and install the new one. An OBD2 scanner is recommended to clear any old codes after installation, but is not strictly required.
What if I have a different GM vehicle like a Cobalt or G6?
This T42 TCM is compatible with a wide array of GM vehicles from 2006-2014. Please check the detailed fitment list on this page or contact us with your VIN to confirm compatibility for your specific model.