If your 2006-2010 Pontiac G6 is suffering from unpredictable shifting, getting stuck in gear, or has an illuminated check engine light pointing to the transmission, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As a seasoned technician, I’ve seen firsthand how a faulty TCM can make a perfectly good car feel unreliable and unsafe. This isn’t just an inconvenience; it’s a critical failure that affects your car’s performance, fuel economy, and drivability. This T42 series TCM, part number 24256960, is the definitive solution, arriving expertly programmed to your vehicle’s specific VIN for a true plug-and-play repair.
The TCM is the electronic brain of your G6’s automatic transmission. It constantly processes data from engine and wheel speed sensors to command precise, smooth gear changes. When it fails, the communication breaks down, leading to the jarring shifts and performance issues you’re experiencing. Our module restores that crucial link, ensuring your transmission operates exactly as the manufacturer intended, without the need for a costly trip to the dealership for programming.
From the Diagnostic Bay: The Ghost in the Transmission
A customer brought in a 2009 Pontiac G6 with a frustrating, intermittent problem. It would drive perfectly for days, then suddenly start shifting hard and throw a P0700 (Transmission Control System Malfunction) code. They’d already replaced a shift solenoid with no luck. After connecting my scan tool and monitoring live data, I noticed the TCM would momentarily drop communication under certain electrical loads. The internal board was failing from years of heat cycles. We installed one of our VIN-programmed T42 modules. The repair took less than 30 minutes, and the car has been shifting flawlessly ever since. It’s a classic example of how this specific Pontiac G6 TCM failure can mimic a more serious mechanical issue.
Is Your Pontiac G6 Showing These Telltale Signs?
A failing TCM doesn’t always mean a complete transmission breakdown. Often, the signs are subtle at first. If you’re noticing any of the following, it’s time to consider a replacement:
- ✔ Harsh, slamming shifts or delayed gear engagement.
- ✔ The vehicle is stuck in “limp mode” (usually second or third gear).
- ✔ Check Engine Light is on with codes like P0700, P0750, or other solenoid-related faults.
- ✔ Inability to upshift or downshift, leading to poor acceleration and efficiency.
- ✔ A noticeable drop in fuel economy.
- ✔ Intermittent loss of communication with the module, causing erratic behavior.
A Straightforward Guide to Your G6 TCM Installation
One of the best features of this module is its ease of installation. For the Pontiac G6 TCM, the location is very accessible, making this a job most DIY enthusiasts can handle in their own garage. No special tools are needed beyond basic hand tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the vehicle’s computer systems.
- Locate the Module: On the 2006-2010 Pontiac G6, the TCM is conveniently located on the driver’s side of the engine bay, mounted to the LH strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. Press the release tabs firmly to avoid damaging the clips. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Reconnect the electrical harnesses, ensuring they click securely into position.
- Final Steps: Reconnect the negative battery terminal. While our programming handles the critical setup, it’s good practice to use a basic OBD-II scan tool to clear any stored fault codes from the ECU. Start the car and enjoy your smooth-shifting transmission!
Verified Vehicle Compatibility List
This T42 TCM is a direct replacement for a wide range of General Motors vehicles. While this page focuses on the Pontiac G6 TCM, it is also compatible with the following models. Please verify your part number (24256960 or an interchange number) to ensure a perfect fit.
- ✔ Pontiac G6 (2006-2010) – Transmission; (LH strut tower)
- ✔ Chevrolet Cobalt (2006-2010) – Transmission; (LH strut tower)
- ✔ Saturn Aura (2007-2009) – Transmission; (LH frame rail front)
- ✔ Chevrolet Malibu (2006-2010) – Transmission; (LH frame rail)
- ✔ Chevrolet HHR (2006-2011) – Transmission; (LH engine compartment)
- ✔ And many other GM models listed in the fitment guide.
Frequently Asked Questions
What does a VIN-programmed TCM mean for me?
It means the module arrives ready for installation right out of the box. We load it with the latest GM software specific to your car’s VIN, so it communicates perfectly with your engine and other systems. This saves you a trip to the dealer and hundreds in programming fees.
Is this a difficult part to install on my Pontiac G6?
No, this is considered a very straightforward repair. The TCM is located on the driver’s side strut tower in the engine bay, making it easy to access. With basic hand tools, most people can complete the swap in under 30 minutes.
Do I need to send my old TCM back?
No core charge is required for this part. You can keep your old module or dispose of it responsibly without any hassle or extra cost.
Will this fix a P0700 diagnostic 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 (like internal failure), you should always diagnose any other codes that appear alongside it. In many cases where the TCM itself is faulty, replacing it will clear the P0700 code.
How do I provide my VIN for programming?
During the checkout process, you will be prompted to enter your vehicle’s 17-digit VIN. This is crucial for us to ensure the module is programmed correctly for your specific vehicle configuration.