If your 2006-2010 Pontiac G6 is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As an auto repair professional with over two decades of experience, I’ve seen firsthand how a faulty TCM can turn a reliable daily driver into a source of constant frustration. This isn’t just an inconvenience; it’s a critical component failure that affects your car’s performance, fuel economy, and safety. This T42 TCM is the direct-fit, reliable solution you need to restore your G6’s smooth, responsive shifting.
The biggest hurdle for many DIYers and even professional shops is the programming. A blank module from the dealership requires expensive, specialized equipment to link it to your vehicle. We eliminate that step entirely. By providing your vehicle’s VIN during checkout, we program the module for you. It arrives at your door ready for a true plug-and-play installation, saving you time, money, and a trip to the dealer. This is the same high-quality solution I would use in my own service bay to get a customer’s car back on the road with confidence.
A Technician’s Notebook: The G6 That Wouldn’t Shift
A customer brought in their 2008 Pontiac G6 with a classic complaint: the car would drive fine for a few minutes, then suddenly slam into gear and the check engine light would pop on. They were getting a P0700 code, which is a general transmission fault. After checking the basics—fluid level and condition—we scanned for more specific codes and found a solenoid circuit fault. The tricky part was that the issue was intermittent. We knew from experience that on these GM platforms, the T42 TCM is a common point of failure. Heat cycles and vibrations cause internal solder joints to crack, leading to exactly these kinds of unpredictable electrical faults. We installed a pre-programmed TCM, and the problem was solved instantly. The car shifted perfectly on a long test drive, proving the module was the root cause.
Diagnosing a Faulty 2006-2010 G6 TCM
A failing TCM can mimic other transmission problems, but there are key indicators to watch for. If your Pontiac G6 is exhibiting these behaviors, the TCM is a highly probable cause. Confirming these symptoms can save you from replacing perfectly good mechanical parts.
- âś” Experiencing harsh, delayed, or slamming gear shifts.
- âś” The vehicle is stuck in a single gear (often called “limp mode”).
- âś” Check Engine Light or Transmission Warning Light is illuminated with codes like P0700, P0750, or other solenoid-related DTCs.
- âś” Inability to upshift or downshift, resulting in poor acceleration and fuel economy.
- âś” Complete loss of communication with the transmission module.
- âś” Unpredictable electrical behavior related to transmission function.
A Straightforward Guide to Installation
Replacing the TCM on your Pontiac G6 is a job most DIY enthusiasts can handle in under 30 minutes with basic tools. The module is conveniently located for easy access.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work. This prevents short circuits and helps reset the vehicle’s electronic systems.
- Locate the Module: On the 2006-2010 Pontiac G6, the TCM is typically found mounted on the driver’s side strut tower in the engine bay. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the electrical harnesses, ensuring they click into place.
- Final Steps: Reconnect the battery terminal. While the module is pre-programmed, it’s good practice to use a basic OBD2 scan tool to clear any stored fault codes from the ECU. Start the car and enjoy your smooth-shifting transmission!
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct replacement for part number YNXS and other interchangeable numbers. While this page focuses on the 2006-2010 G6 TCM, this part also fits a wide range of other General Motors vehicles. Please verify your specific model and part number for a guaranteed fit.
Fits Pontiac G6 Model Years: 2006, 2007, 2008, 2009, 2010 (Transmission; located at LH strut tower)
Also fits other GM models including Chevrolet Cobalt, HHR, Malibu; Saturn Aura, Ion, Vue, and more. Cross-reference part numbers 24252114, 24234503, 24242391 to ensure compatibility.
Do I need to take my car to a dealer after installation?
Do I need to take my car to a dealer after installation?
No. This module comes fully programmed to your car’s specific VIN. This eliminates the need for any additional programming or setup at a dealership, making it a true plug-and-play solution.
What is part number YNXS?
YNXS is a service number used by GM to identify this specific T42 Transmission Control Module. It is interchangeable with other part numbers like 24252114, 24234503, and more, ensuring it functions correctly in your vehicle.
Is this a difficult part for a DIYer to replace?
Not at all. For the Pontiac G6, the TCM is located on the driver’s side strut tower, making it one of the easier modules to access and replace. With basic hand tools, the job typically takes less than half an hour.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the main engine computer. While this module often resolves the root cause (like a solenoid circuit error that triggers the P0700), you should ideally scan for more specific P-codes to confirm the diagnosis.
Is there a core charge for my old part?
No, we do not require you to send back your old module. There is no core charge associated with this purchase, saving you the hassle and expense of a return shipment.