Restore Peak Performance to Your Pontiac Grand Prix
If your 2006-2008 Pontiac Grand Prix is suffering from erratic shifting, getting stuck in gear, or throwing transmission-related check engine lights, the culprit is often a failing Transmission Control Module (TCM). As a technician with over two decades of experience under the hood, I’ve seen firsthand how a faulty TCM can cripple an otherwise reliable vehicle. This isn’t just an inconvenience; it’s a critical failure that affects drivability and safety. This T42 TCM, part number 24243901, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
The TCM is the electronic brain of your automatic transmission, responsible for commanding gear changes, managing torque converter clutch lockup, and monitoring for faults. When it fails, communication breaks down, leading to the frustrating symptoms you’re likely experiencing. Our module restores that crucial link, ensuring your transmission operates precisely as the manufacturer intended, without the need for an expensive and time-consuming trip to the dealership for programming.
A Technician’s Notebook: The Intermittent Shifting Mystery
A customer brought in their ’07 Grand Prix with a complaint that stumped two other shops: intermittent, bone-jarring shifts and occasionally getting stuck in 3rd gear, but with no consistent codes. After a test drive, I suspected the TCM. Back at the shop, I monitored live data and saw the module’s commands were dropping out randomly. Heat soak from being located under the air cleaner housing had weakened the internal circuits over the years. We installed a VIN-programmed T42 module, and the car drove like new. This is a classic failure mode, and a pre-programmed module is the fastest, most reliable fix.
Is Your Grand Prix Showing These Transmission Warning Signs?
- ✔️ Harsh, delayed, or unpredictable gear shifts.
- ✔️ The vehicle is stuck in “limp mode” (usually 2nd or 3rd gear) and won’t shift up or down.
- ✔️ Check Engine Light or Transmission Warning Light is illuminated on the dash.
- ✔️ You’ve pulled Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults.
- ✔️ A noticeable drop in fuel economy or a transmission that seems to be overheating.
- ✔️ Complete failure to engage gears or loss of communication with the scan tool.
DIY-Friendly Installation for Your Grand Prix
Replacing the TCM on your Grand Prix is a straightforward job that most DIY mechanics can complete in under 30 minutes with basic hand tools. This saves you significant labor costs and vehicle downtime.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic component replacement.
- Locate the Module: On the 2006-2008 Grand Prix, the TCM is conveniently located under the lower air cleaner housing in the engine bay.
- Remove the Old Unit: Carefully unplug the electrical connectors. Press the release tabs firmly to avoid damaging them. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely plug in the electrical connectors until they click.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Fitment for Your Vehicle
This module is a direct-fit replacement for the following vehicles, specifically programmed for your VIN upon order. While it fits many GM models, the installation location notes are provided for your convenience.
- Pontiac Grand Prix (2006-2008): Transmission; located under the lower air cleaner housing.
- Chevrolet Impala (2006-2011): Transmission; located under the lower air cleaner housing.
- Buick LaCrosse / Allure (2006-2009): Transmission; located under the lower air cleaner housing.
- Chevrolet Monte Carlo (2006-2007): Transmission; located under the lower air cleaner housing.
- …and many other GM cars, trucks, and SUVs. Please verify your part number (24243901 or an interchange) for guaranteed compatibility.
Frequently Asked Questions
What does ‘VIN Programmed’ mean for my Grand Prix?
It means we load your car’s unique 17-digit Vehicle Identification Number (VIN) and the latest GM software onto the module before shipping. This ensures it communicates perfectly with your car’s engine computer and other systems right out of the box, eliminating the need for dealership programming.
Do I need to send my old TCM back (core charge)?
No, there is absolutely no core charge or need to return your old part. You can dispose of it or keep it without any hassle, simplifying your repair process.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main engine computer (ECM) to turn on the check engine light. While this module often resolves the underlying issue causing the P0700 (like a solenoid circuit fault), you should always diagnose the specific codes stored within the TCM itself for a complete picture.
Is this a difficult part to install myself?
Not at all. For a 2006-2008 Grand Prix, the location under the airbox is accessible with basic tools. The entire process typically takes less than half an hour, making it a very DIY-friendly repair.
What is the warranty on this part?
This Transmission Control Module comes with a one-year warranty, giving you confidence and peace of mind in the quality and reliability of your repair.