Restore Flawless Shifting to Your Chevrolet HHR
If your 2006-2011 Chevrolet HHR is suffering from delayed shifts, getting stuck in gear, or throwing transmission codes, the culprit is often a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, the TCM is responsible for every gear change. Over time, heat and vibration—common in the HHR’s engine compartment—can degrade internal components, leading to the frustrating and unpredictable performance you’re experiencing. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded. This replacement T42 TCM, part number 24235340, is the definitive solution to restore your vehicle’s factory performance and your peace of mind.
Case Study: A Tricky Diagnosis
I had a 2009 HHR come into my shop with classic symptoms: harsh 1-2 shift and intermittent limp mode with a P0752 (Shift Solenoid ‘A’ Stuck On) code. The owner had already replaced the solenoid twice at another shop, with no success. After running diagnostics, I saw the command signal from the TCM was erratic. The module itself was failing internally and sending bad commands, causing a perfectly good solenoid to malfunction. We installed one of our VIN-programmed TCMs, cleared the codes, and the car shifted like new. This is a perfect example of how a faulty module can mimic a mechanical failure, and why starting with a reliable, properly programmed TCM is critical.
Is Your HHR Exhibiting These Shifting Problems?
A failing TCM will give you clear warning signs. If you’re noticing any of the following, it’s time to consider a replacement. In my 20 years of experience, these are the most common indicators I see in the service bay for a failing GM T42 module.
- âś” Harsh, slamming, or erratic gear shifts.
- âś” Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- âś” The Check Engine Light or Transmission Warning Light is on.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0751, P0756, or other solenoid-related faults.
- âś” Delayed engagement when shifting from Park to Drive or Reverse.
- âś” Poor fuel economy due to incorrect gear selection.
The Power of Pre-Programmed Convenience
The single biggest hurdle in replacing a modern electronic module is programming. Dealerships charge hundreds for this service alone. Our process eliminates that completely. We flash this 2006-2011 HHR Transmission Module with your vehicle’s specific VIN and the latest GM software updates before it ships. This ensures it communicates perfectly with your vehicle’s Engine Control Module (ECM) and other systems right out of the box. There are no extra steps, no expensive scan tools needed for setup, and absolutely no trip to the dealer. It’s a true plug-and-play repair that saves you significant time and money.
Straightforward DIY Installation Guide
For the Chevy HHR, this is a very accessible repair for a DIY enthusiast. You can have your vehicle back on the road in under an hour with basic hand tools. The TCM is located in the left (driver’s side) front of the engine compartment.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On the HHR, the TCM is typically mounted to the driver’s side of the engine bay, near the strut tower. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unclip the wiring harnesses. Be gentle with the plastic tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the wiring harnesses, ensuring they click securely into place.
- Reconnect and Verify: Reconnect the negative battery terminal. Start the vehicle and check for any warning lights. A short test drive will confirm that shifting performance has been restored.
Verified Fitment for Your General Motors Vehicle
While this page is dedicated to the 2006-2011 HHR Transmission Module, this part (24235340) is a genuine T42 TCM that fits a wide range of GM vehicles. Please verify your specific model and location below. If you have any questions, our expert team is here to help you confirm the correct fitment.
This part will fit these makes and models with these options:
- HHR 2006-2011: Transmission; (LH engine compartment)
- COBALT 2006-2010: Transmission; (LH strut tower)
- G5 2007-2010: Transmission; (LH strut tower)
- G6 2006-2010: Transmission; (LH strut tower)
- IMPALA 2006-2011: Transmission; (lower air cleaner housing)
- MALIBU 2006-2010: Transmission; (LH frame rail)
- MONTE CARLO 2006-07: Transmission; (lower air cleaner housing)
- SATURN AURA 2007-2009: Transmission; (LH frame rail front)
- SATURN ION 2006-2007: Transmission; (behind LH strut tower)
- SATURN VUE 2007-2010: Transmission; 2.4L models
- And many other GM cars, trucks, and SUVs. Please see the full fitment list provided in the product details.
Do I need to take my car to the dealer after installing this?
Do I need to take my car to the dealer after installing this?
No. This module comes fully programmed to your vehicle’s VIN. It is a plug-and-play solution that requires no additional programming or dealership visits, saving you time and money.
What is the warranty on this part?
This part is backed by our standard one-year warranty, ensuring it meets or exceeds OEM standards for reliability and performance.
Is this part number 24235340 interchangeable with other numbers?
Yes, this T42 TCM is a direct replacement for many service numbers, including 24252114, 24234503, 24242391, and others listed in the product details. It is the correct hardware for a wide range of GM applications.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request, meaning the TCM has detected a problem and asked the main computer to turn on the check engine light. While this module often resolves the root cause (like an internal TCM failure or a bad solenoid driver), you should always diagnose any other specific codes (e.g., P0751, P0756) that accompany it.