Restore Your Minivan’s Drivability and Reliability
As a mechanic with over two decades of experience, I know how unsettling it is when your family’s Pontiac Montana starts shifting erratically or gets stuck in gear. That check engine light is more than an annoyance; it’s a sign that the heart of your transmission’s logic—the Transmission Control Module (TCM)—is failing. This isn’t just about performance; it’s about safety and peace of mind. You need a reliable fix that gets you back on the road without costly dealership visits. This VIN-programmed T42 TCM, part number 24234274, is the definitive solution for your 2006-2009 Pontiac Montana, engineered to restore the smooth, predictable shifting you depend on.
From the Diagnostic Bay: The Intermittent Montana
A customer brought in their ’07 Montana, complaining of random, harsh downshifts and occasionally getting stuck in 3rd gear—a classic limp mode symptom. Their local shop couldn’t find a consistent fault, as the issue would disappear after a restart. After hooking up my scan tool, I saw a history of intermittent solenoid circuit codes and a P0700 (Transmission Control System Malfunction). In my experience, especially with these GM platforms, this pattern almost always points to a failing TCM. The internal electronics break down from heat and vibration, causing unpredictable signals. We replaced it with a VIN-programmed module like this one, and the problem was solved permanently. The customer was relieved to have their dependable family vehicle back.
Common Signs of a Failing 2006-2009 Montana TCM
If your vehicle is experiencing any of the following issues, a faulty TCM is the most likely culprit. Addressing it promptly can prevent further damage to your transmission’s mechanical components.
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ Vehicle is stuck in “limp mode” and won’t shift out of a single gear.
- ✔ Check Engine Light is illuminated with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, or other solenoid-specific codes.
- ✔ Complete failure to upshift or downshift, leading to poor acceleration.
- ✔ A noticeable decrease in fuel economy due to inefficient shifting.
- ✔ The transmission feels like it’s slipping between gears.
A Straightforward Guide to Your Montana TCM Installation
This is a repair you can confidently handle in your own driveway. Because we pre-program the module to your vehicle’s VIN, you can skip the expensive trip to the dealership. The entire process typically takes less than 30 minutes.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On your 2006-2009 Pontiac Montana, the TCM is conveniently located on the driver’s side of the engine bay, mounted to the left-hand (LH) strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly to avoid damaging them. Then, unbolt the old module from its mounting bracket.
- Install the New TCM: Mount the new module onto the strut tower and securely fasten the bolts. Reconnect the electrical harnesses, ensuring they click into place.
- Final Steps: Reconnect the negative battery terminal. While the system often resets itself, it’s best practice to use a basic OBD-II scan tool to clear any stored fault codes. Start the engine and take a test drive to confirm smooth shifting.
Verified Vehicle Compatibility List
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles. While this page focuses on the 2006-2009 Montana TCM, it is also compatible with the following models. Please verify your specific model and year.
- Pontiac Montana: 2006-2009 (LH strut tower)
- Chevrolet Cobalt / Pontiac G5 / Saturn Ion: 2006-2010 (LH strut tower)
- Chevrolet Impala / Monte Carlo / Buick Allure / LaCrosse: 2006-2011 (lower air cleaner housing)
- Chevrolet HHR: 2006-2011 (LH engine compartment)
- Chevrolet Silverado / GMC Sierra Trucks: 2007-2013 (next to battery)
- Chevrolet Tahoe / GMC Yukon / Suburban: 2007-2009 (next to battery)
- And many more GM models from 2006-2014.
This part is interchangeable with service numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24238856, and others.
Frequently Asked Questions
Frequently Asked Questions
Do I need to take my van to the dealership for programming?
No. We program the module to your specific VIN before shipping. It arrives ready for plug-and-play installation, saving you time and money.
Is this a difficult part to install myself?
Not at all. For a Pontiac Montana, the TCM is easily accessible on the driver’s side strut tower. With basic hand tools, most DIYers can complete the job in under 30 minutes.
What happens if I don’t replace a failing TCM?
Continuing to drive with a faulty TCM can cause long-term damage. Erratic shifting and pressure control issues can lead to premature wear on clutches and bands, resulting in a much more expensive transmission rebuild.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part, so there’s no need to worry about return shipping or extra costs.
How do I provide my VIN for programming?
You will be prompted to enter your vehicle’s 17-digit VIN during the checkout process. Please double-check it for accuracy to ensure perfect compatibility.