Is your 2006-2008 Pontiac Grand Prix suffering from harsh, erratic shifting, getting stuck in gear, or flashing a check engine light? Don’t let a faulty Transmission Control Module (TCM) sideline your car. As a technician with over two decades of experience, I’ve seen how a failing TCM can mimic more serious transmission problems, leading to costly and unnecessary repairs. This VIN-programmed T42 Transmission Control Module, part number 24240449, is the direct, reliable solution to restore your vehicle’s performance and get you back on the road with confidence.
This isn’t just a replacement part; it’s a complete fix. We pre-program the module to your vehicle’s specific VIN before shipping, which means it arrives ready for a true plug-and-play installation. You can bypass expensive dealership programming fees and lengthy service appointments. The 2006-2008 Grand Prix TCM is the brain of your automatic transmission, responsible for managing shift points, torque converter lockup, and line pressure. When it fails, you get the frustrating symptoms that disrupt your drive. This module restores that critical communication, ensuring smooth, predictable gear changes and optimal fuel efficiency.
A Technician’s Notebook: The Misleading Solenoid Codes
A customer brought in a 2007 Grand Prix with a classic complaint: intermittent harsh 1-2 shifts and a P0752 code (Shift Solenoid ‘A’ Stuck On). They had already spent a few hundred dollars having a local shop replace the solenoid, but the problem returned within a week. After hooking up my scanner and monitoring live data, I noticed the command signal from the TCM was erratic, even when the transmission was behaving. The internal drivers in these T42 modules are a common failure point. We installed a VIN-programmed TCM, cleared the codes, and the car has been shifting perfectly ever since. It’s a textbook case of how a faulty module can send you chasing the wrong parts.
Is Your Grand Prix Showing These Symptoms?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Harsh, slamming, or delayed gear shifts.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, P0751, or other solenoid-related faults.
- ✔ Failure to upshift or downshift correctly.
- ✔ A sudden drop in fuel economy.
- ✔ Intermittent loss of communication with the module.
A Straightforward Guide to Installation
Replacing the 2006-2008 Grand Prix TCM is a job most DIYers can handle in under an hour with basic hand tools. For the Grand Prix, the module is conveniently located under the lower air cleaner housing.
- Safety First: Disconnect the negative terminal from your car’s battery to prevent any electrical shorts and to help reset the system.
- Access the Module: Remove the air cleaner box assembly to gain clear access to the TCM.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical connectors, ensuring they click securely into place.
- Final Steps: Reinstall the air cleaner assembly and reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a basic scan tool, it’s good practice to clear any lingering fault codes.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24240449 and is interchangeable with many other GM service numbers. While it is guaranteed to fit the 2006-2008 Pontiac Grand Prix, it also fits a wide range of other GM vehicles. Please verify your part number or contact us with your VIN to ensure perfect fitment.
Frequently Asked Questions
Do I need to do any programming after installation?
No. This module comes fully programmed to your vehicle’s VIN. It is a plug-and-play solution, saving you a trip to the dealership. Just install it and you’re ready to go.
Is this a new or used part?
This is a high-quality, OEM-standard replacement part, tested for reliability and backed by our one-year warranty. It is not a used part pulled from a junkyard.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request, meaning the TCM has detected a problem and asked the main computer (PCM) to turn on the check engine light. In many cases, a faulty TCM is the root cause of the P0700 and its accompanying specific codes (like P0752, etc.). Replacing the module often resolves these issues.
Do I need to return my old TCM?
No, there is no core charge for this part. You can keep or dispose of your old module without any hassle.
Where is the TCM located on my 2007 Grand Prix?
On the 2006-2008 Pontiac Grand Prix, the Transmission Control Module is located in the engine bay, mounted to the lower air cleaner housing.