Restore Smooth, Reliable Shifting to Your Pontiac Montana
Is your 2006-2009 Pontiac Montana struggling with harsh shifting, getting stuck in gear, or throwing transmission codes? A failing Transmission Control Module (TCM) is one of the most common culprits behind these frustrating and potentially unsafe issues. As a technician with over two decades of experience, I’ve seen firsthand how a faulty TCM can sideline a perfectly good family vehicle. This replacement T42 TCM, part number 24238856, is the definitive solution to get your minivan back on the road with confidence.
The TCM is the brain of your automatic transmission, controlling everything from shift points to torque converter lockup. When it fails, communication breaks down, leading to the unpredictable performance you’re likely experiencing. Our module comes pre-programmed to your vehicle’s specific VIN, eliminating the need for expensive dealership visits and complex programming tools. It’s a true plug-and-play fix designed for both professional installers and determined DIYers.
A Technician’s Notebook
A customer brought in their ’07 Montana, complaining of intermittent ‘slamming’ into gear and the check engine light flashing on and off. They’d already replaced a shift solenoid with no luck. A quick scan showed a P0752 (Shift Solenoid ‘A’ Stuck On) and a general P0700 code. Experience told me that while the code points to a solenoid, the intermittent nature often traces back to the module’s driver circuit failing under heat. We installed one of our VIN-programmed TCMs, cleared the codes, and the van shifted perfectly on the test drive. The problem wasn’t the solenoid itself, but the command center telling it what to do. This is a classic failure pattern for these modules.
Is Your Montana Showing These Telltale Signs?
A failing TCM can manifest in several ways. If you’re noticing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, delayed, or erratic gear shifts that make driving uncomfortable.
- ✔ The vehicle is stuck in “limp mode,” often refusing to shift out of 2nd or 3rd gear.
- ✔ The Check Engine Light or a transmission-specific warning light is illuminated on your dash.
- ✔ Your scan tool shows Diagnostic Trouble Codes (DTCs) like P0700, P0750-P0758, or other solenoid-related faults.
- ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
- ✔ Complete loss of communication with the transmission, resulting in a no-shift condition.
Your Solution to a Faulty 2006-2009 Montana TCM
Don’t let a bad module lead to a costly transmission replacement. This part is engineered to OEM specifications for a precise fit and reliable function. The most significant benefit is our professional VIN programming service. We flash the module with the latest GM software calibrated specifically for your van before it even ships. This ensures it communicates perfectly with your vehicle’s other systems, like the Engine Control Module (ECM), right out of the box.
DIY Installation: Get Your Minivan Running Smoothly
- ✔ 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 the Pontiac Montana and similar vans (Uplander, Terraza), the TCM is typically found on the driver’s side of the engine bay, mounted to the LH strut tower.
- ✔ Disconnect and Remove: Carefully unclip the electrical connectors. Use a socket wrench to remove the mounting bolts holding the old module in place.
- ✔ Install the New TCM: Mount the new module securely with the bolts and firmly reconnect the electrical harnesses. Ensure they click into place.
- ✔ Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s always best practice to use a basic scan tool to clear any stored DTCs from the vehicle’s memory. Start the engine and take a test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 Transmission Control Module is a direct replacement for part number 24238856 and is interchangeable with other service numbers. While this page focuses on the Pontiac Montana, it is compatible with a wide range of GM vehicles. The fitment list below is a sample of compatible models. For your 2006-2009 Montana, this module is located at the LH strut tower.
This part will also fit other models including: Chevrolet Cobalt, HHR, Impala, Malibu, Monte Carlo; Buick Allure, LaCrosse, Lucerne; Pontiac G5, G6, Grand Prix; Saturn Aura, Ion, Vue; and many more from 2006-2014. Always verify the part number for your specific application.
Frequently Asked Questions
Do I need to take my van to the dealer for programming?
No. This module arrives pre-programmed to your vehicle’s VIN. It is a true plug-and-play solution, saving you time and money.
Is this a difficult part for a DIYer to install?
Not at all. For most models like the Montana, it’s located in an accessible spot in the engine bay and requires only basic hand tools. The entire process typically takes less than 30 minutes.
What is the warranty on this 2006-2009 Montana TCM?
This part is backed by our one-year, hassle-free warranty, giving you peace of mind with your purchase.
Will this fix a P0700 trouble code?
A P0700 is a generic code indicating the TCM has detected a fault. Often, replacing a faulty TCM will resolve the P0700 and any other specific transmission codes it was storing.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part without any hassle or need to return it.