Restore Your HHR’s Shifting Performance
Is your 2006-2011 Chevrolet HHR suffering from erratic shifting, getting stuck in gear, or displaying a check engine light? These are classic signs of a failing Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating smooth gear changes, managing torque converter lockup, and monitoring system health. When it fails, it can cause a cascade of frustrating and potentially damaging issues, from poor fuel economy to a complete inability to shift gears.
This genuine GM T42 Transmission Control Module, service part 24238856, is the definitive solution to restore your vehicle’s factory performance. We take the guesswork and extra expense out of the repair by pre-programming the module to your vehicle’s specific VIN. This means it arrives at your door ready for a plug-and-play installation, with no need for a costly trip to the dealership for programming. It’s the most efficient way to get your HHR back on the road, shifting smoothly and reliably.
From the Diagnostic Bay
We recently had a 2009 HHR come in with the complaint of harsh, delayed shifts and a P0700 trouble code. The owner had already spent a significant amount of money replacing shift solenoids at another shop, but the problem persisted. After a quick diagnostic scan, we confirmed the solenoids were functioning correctly, which pointed us directly to the TCM. The internal circuitry had failed, sending erratic signals. We installed one of our VIN-programmed T42 modules, cleared the codes, and the car was shifting like new in under an hour. It’s a common scenario where diagnosing the root cause—the TCM—saves time, money, and frustration.
Symptoms of a Failing 2006-2011 HHR TCM
- ✔ Harsh, slamming, or erratic gear shifts.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Vehicle entering “limp mode,” often stuck in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light illuminated on the dash.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related codes.
- ✔ Complete failure to upshift or downshift.
- ✔ Noticeably decreased fuel efficiency.
- ✔ Intermittent loss of communication with the module.
Plug-and-Play Reliability
This isn’t just a replacement part; it’s a complete solution. By programming the module with the latest GM software updates tied to your VIN, we ensure it communicates flawlessly with your vehicle’s other systems, like the Engine Control Module (ECM). This T42 TCM is built to stringent OEM standards for durability and performance, backed by a one-year warranty for your peace of mind. Installation is straightforward for a DIY mechanic or any professional technician. Located in the LH engine compartment on the HHR, replacement typically takes less than 30 minutes. Simply disconnect the battery, swap the modules, reconnect, and you’re ready to go. No core charge means you can keep your old part without any hassle.
This module is also a direct replacement for a wide range of other GM vehicles utilizing the 4-speed automatic transmission (4L60E, 4L65E, 4L70E). It interchanges with numerous part numbers, including 24252114, 24234503, 24230461, and 24238856, making it a versatile and reliable choice for many cars, trucks, and SUVs.
Frequently Asked Questions
Will this TCM fit my 2008 Chevy HHR?
Yes, this Transmission Control Module is a direct fit for all 2006, 2007, 2008, 2009, 2010, and 2011 Chevrolet HHR models equipped with an automatic transmission.
Do I need to have this module programmed by a dealer?
No. We pre-program the module to your vehicle’s VIN before shipping. This ensures it is ready for installation right out of the box, with no additional programming or flashing required.
What is a T42 TCM?
T42 is the hardware designation for this generation of General Motors Transmission Control Modules. It was widely used in vehicles with 4-speed automatic transmissions like the 4L60E and 4L65E during the mid-2000s to early 2010s.
Where is the TCM located on a Chevy HHR?
On the 2006-2011 Chevrolet HHR, the TCM is typically located in the engine compartment on the driver’s side (LH), often near the strut tower or under the air cleaner box.
Is there a core charge for this part?
No, there is no core charge. You are not required to send your old, faulty module back to us, which simplifies the repair process for you.