End Your Impala’s Shifting Nightmares for Good
If your 2006-2011 Chevrolet Impala is suffering from harsh shifts, getting stuck in gear, or throwing transmission codes, you’ve found the definitive solution. As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by a faulty Transmission Control Module (TCM). The T42 module, specifically part number 24238856, is the electronic brain of your automatic transmission, and when it fails, it can cause a cascade of frustrating and potentially damaging problems. This isn’t just a replacement part; it’s a permanent fix designed to restore your vehicle’s factory performance and reliability.
We take the guesswork and extra cost out of the repair by pre-programming this module to your vehicle’s specific VIN. This means it arrives ready for a true plug-and-play installation, eliminating the need for an expensive trip to the dealership for programming. This is the exact approach I’d take in my own shop to get a customer’s car back on the road quickly and confidently.
Case Study: The Ghost in the Transmission
A customer brought in a 2009 Impala with an issue that was driving them crazy: intermittent limp mode. It would drive fine for days, then suddenly refuse to shift past 2nd gear, with a P0700 code on the scanner. They had already replaced two shift solenoids with no luck. After checking the wiring harness for damage, I suspected the TCM. The internal circuits on these modules can develop micro-fractures from heat cycles, causing intermittent failures that are impossible to predict. We installed a VIN-programmed T42 module, and the problem vanished instantly. It’s a classic example of how chasing symptoms can be costly, while addressing the root cause—the failing TCM—provides a lasting solution.
Is Your Impala Showing These Telltale Signs?
A failing 2006-2011 Impala TCM often presents with clear, identifiable symptoms. If you’re experiencing any of the following, a faulty module is the most likely culprit:
- ✔ Erratic, hard, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle is stuck in “limp mode,” typically locked in 2nd or 3rd gear.
- ✔ Your Check Engine Light or transmission warning light is on, with Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-related faults.
- ✔ A complete failure to upshift or downshift, leading to poor acceleration and terrible gas mileage.
- ✔ The torque converter failing to lock up at highway speeds, causing engine RPMs to be unusually high.
- ✔ Intermittent loss of communication with the scanner or other modules.
Your 30-Minute Installation Guide
One of the best features of this module is its straightforward installation. For the 2006-2011 Impala, you’ll find the TCM located under the lower air cleaner housing. You don’t need a vehicle lift or specialized tools.
- Safety First: Disconnect the negative terminal from your car’s battery to prevent any electrical shorts and help reset the vehicle’s systems.
- Access the Module: Remove the air cleaner box assembly. This will give you clear access to the TCM mounted below it.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical connectors. You’ll hear a click as they lock in.
- Reassemble and Reconnect: Reinstall the air cleaner assembly and reconnect the negative battery terminal.
- Final Steps: Start the vehicle. While our programming handles the critical setup, it’s good practice to use a basic OBD2 scanner to clear any stored fault codes to ensure a clean slate.
Verified Vehicle Compatibility
While this part is a perfect match for the 2006-2011 Chevrolet Impala, this T42 TCM is also compatible with a wide range of other General Motors vehicles. Please verify your part number (24238856 or an interchangeable number) and model for a guaranteed fit.
- Chevrolet: Impala (06-11), Monte Carlo (06-07), Malibu (06-10), Cobalt (06-10), HHR (06-11), and more.
- Pontiac: G6 (06-10), Grand Prix (06-08), Pursuit (06).
- Buick: LaCrosse (06-09), Allure (06-09), Lucerne (06-11).
- Saturn: Aura (07-09), Ion (06-07), Vue (07-10).
- Note: This module also fits many GM trucks and SUVs like the Silverado, Tahoe, and Yukon. See the full fitment list for details.