Restore Smooth Shifting to Your Chevrolet HHR
Is your 2006-2011 Chevy HHR suffering from jerky shifting, getting stuck in gear, or displaying a persistent check engine light? These are classic signs of a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a faulty TCM can disrupt communication, leading to poor performance, decreased fuel economy, and frustrating driving experiences. This direct-replacement T42 TCM, part number 24235340, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
Case Study: The Ghost in the HHR Transmission
I remember a 2009 HHR that came into my shop with a problem that was driving the owner crazy. The car would shift perfectly for days, then suddenly start banging into gear or refuse to shift past 2nd. They’d already replaced a shift solenoid with no luck. After connecting my scan tool, I saw intermittent communication loss codes pointing toward the TCM. These modules, especially when subjected to years of engine bay heat, can develop internal circuit failures. We installed a VIN-programmed 2006-2011 HHR TCM, and the problem vanished instantly. The pre-programming saved the customer a trip to the dealer and got their daily driver back to being reliable.
Is Your HHR Showing These Transmission Faults?
A failing TCM can manifest in several ways. If you’re noticing any of the following, it’s highly likely your module is the culprit. A proper diagnosis is key, but these symptoms are strong indicators.
- ✔ Harsh, erratic, or delayed gear shifts.
- ✔ Vehicle enters “limp mode,” often stuck in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as the generic P0700 (Transmission Control System Malfunction) or specific solenoid codes like P0750-P0758.
- ✔ A complete failure to shift up or down.
- ✔ Noticeable decrease in fuel efficiency.
A Straightforward Guide to Installation
One of the best features of this module is how simple the replacement is. For the DIY mechanic, this is a job you can complete in your driveway in under 30 minutes with basic hand tools. This specific 2006-2011 HHR TCM is engineered for a perfect fit.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic component replacement.
- Locate the Module: On the Chevy HHR, the TCM is conveniently located in the left-hand (driver’s side) of the engine compartment.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New TCM: Mount your new, pre-programmed module in the same location and securely fasten it. Reconnect the electrical connectors, ensuring they click into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Fitment Across Multiple GM Models
While this is the ideal solution for your HHR, this T42 module is also compatible with a wide range of other General Motors vehicles. Please verify your part number (24235340) or check the list below. This part is interchangeable with service numbers including 24252114, 24234503, 24230461, and others.
- Chevrolet HHR: 2006-2011 (LH engine compartment)
- Chevrolet Cobalt: 2006-2010 (LH strut tower)
- Pontiac G6: 2006-2010 (LH strut tower)
- Saturn Ion: 2006-2007 (behind LH strut tower)
- And many more GM cars, trucks, and SUVs.
Frequently Asked Questions
Do I need to take my car to the dealership for programming?
No. This module comes fully programmed to your vehicle’s VIN. It’s ready for installation right out of the box, saving you time and the high cost of dealer programming.
Is this a difficult part to install myself?
Not at all. For most DIYers with basic tools, this is a very straightforward job that takes less than 30 minutes. The location on the HHR is easily accessible in the engine bay.
What is a core charge?
A core charge is a deposit you pay until you return your old part. We make it simple: there is NO core charge on this TCM. You can keep your old part without any hassle.
What if this doesn’t fix my problem?
This part is backed by our one-year warranty. We also have expert support available to help with diagnostics. A failing TCM is the most common cause of these symptoms, but we’re here to help ensure you get the right fix.
Will this work for other GM vehicles besides the HHR?
Yes, this T42 TCM fits a wide variety of GM vehicles from 2006-2014. Please check the detailed fitment list or match your original part number to ensure compatibility.