Is Your Chevy HHR Shifting Erratically?
If you’re experiencing harsh shifting, delayed gear engagement, or your 2006-2011 Chevrolet 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 managing shift points, torque converter lockup, and fluid pressure. When it fails, it can cause a host of frustrating and potentially damaging drivability issues, often illuminating the check engine light with transmission-related codes.
From the Diagnostic Bay
We recently had a 2009 HHR come into the shop with the classic symptoms: it wouldn’t shift past 2nd gear and the transmission warning light was on. The customer was worried about a costly transmission rebuild. After a quick scan, we pulled a P0700 code and several solenoid circuit faults. Instead of starting with expensive internal repairs, we inspected the TCM. We noticed no physical damage, but experience pointed to an internal electronic failure. We swapped in a VIN-programmed T42 module, cleared the codes, and took it for a test drive. The HHR shifted perfectly through all gears, smooth as the day it left the factory. It was a 30-minute fix that saved the customer thousands.
Symptoms of a Failing HHR Transmission Module
A faulty TCM can manifest in various ways. Keep an eye out for these common warning signs in your vehicle:
- ✔ Harsh or Erratic Shifting: Your vehicle may slam into gear, hesitate, or shift at the wrong times.
- ✔ Stuck in Gear / Limp Mode: The transmission may refuse to shift, often getting stuck in 2nd or 3rd gear 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): Common codes include P0700 (Transmission Control System Malfunction), P0750-P0774 (Shift Solenoid errors), and other communication codes.
- ✔ Poor Fuel Economy: Inefficient shifting and torque converter operation can lead to a noticeable drop in MPG.
- ✔ No Upshift or Downshift: The vehicle may struggle to accelerate or downshift when you need power.
The Plug-and-Play Solution: VIN Programmed for Your HHR
This genuine GM T42 Transmission Control Module is the definitive solution to your HHR’s transmission woes. We take the hassle out of the repair by pre-programming the module to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This critical step ensures complete compatibility and communication with your vehicle’s other electronic systems, like the Engine Control Module (ECM) and Body Control Module (BCM).
Why is VIN programming essential? Without it, the module won’t recognize your vehicle’s specific build, leading to continued shifting problems or a no-start condition. Our service eliminates the need for an expensive trip to the dealership for programming, allowing you to perform the installation yourself or have your trusted mechanic do it. This module arrives ready for a true plug-and-play installation.
Installation is Simple
For the 2006-2011 Chevrolet HHR, the TCM is conveniently located in the engine compartment on the driver’s side, attached to the LH engine compartment wall. The replacement process is straightforward and can typically be completed in under 30 minutes with basic hand tools. Simply disconnect the battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Reconnect everything, and you’re ready to go. We recommend using a basic scan tool to clear any stored DTCs after installation for a clean slate.
This module is a direct replacement for a wide range of GM part numbers, including 24252114, 24234503, 24230461, 24234274, 24235753, 24240449, and many more. Restore the smooth, reliable performance of your vehicle’s transmission today.
Frequently Asked Questions
What does ‘VIN Programmed’ mean for my HHR?
It means we load the module with the specific software and calibration file from GM that matches your vehicle’s exact VIN. This ensures the TCM works perfectly with your HHR’s engine, options, and tire size, providing optimal shift quality and performance right out of the box.
Do I need to visit a dealer after installing this part?
No. Because the module is pre-programmed to your VIN, no additional dealership programming or setup procedures are required. This is a plug-and-play installation.
Where is the TCM located on a 2006-2011 Chevy HHR?
The Transmission Control Module on the HHR is located in the engine bay, typically mounted to the driver’s side (LH) engine compartment wall or strut tower area.
Will this module fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the root cause (such as internal solenoid driver failure), it’s essential to diagnose any other codes that are present. In many cases, replacing a faulty TCM will clear the P0700 and related codes.
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, saving you time and shipping costs.