Is your 2006-2009 Pontiac Montana struggling with harsh shifting, getting stuck in gear, or showing a check engine light? These are classic signs of a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless families frustrated by unreliable vehicles. A faulty TCM isn’t just an annoyance; it’s a critical failure that can leave you stranded. This T42 Transmission Control Module, part number 24235340, is the definitive solution to restore your minivan’s dependable performance.
This isn’t just a replacement part; it’s a complete, ready-to-install fix. We pre-program each module to your vehicle’s specific VIN, eliminating the need for expensive and time-consuming dealership visits for programming. This ensures that once installed, the module communicates perfectly with your Montana’s engine computer and transmission, restoring the smooth, predictable shifting you rely on. By precisely managing shift points and torque converter lockup, this module not only fixes common issues but also helps improve fuel economy and reduce wear on your transmission.
Is Your Pontiac Montana Showing These Symptoms?
- ✔️ Abrupt, jerky, or delayed gear shifts that make driving uncomfortable.
- ✔️ The vehicle is stuck in “limp mode,” often locked in 2nd or 3rd gear.
- ✔️ An illuminated Check Engine Light or Transmission Warning Light on your dash.
- ✔️ Diagnostic Trouble Codes (DTCs) stored in the system, such as the general P0700 code or specific solenoid codes like P0753 or P0758.
- ✔️ A noticeable drop in fuel efficiency or a transmission that seems to be overheating.
- ✔️ Complete loss of communication with the TCM, leading to a no-shift condition.
A Technician’s Notebook: The Montana That Wouldn’t Shift
A customer brought in their ’08 Pontiac Montana, explaining it was their main vehicle for getting the kids to school. Intermittently, it would refuse to shift out of what felt like third gear, and the check engine light was on. They were worried about a massive transmission repair bill. I pulled the codes and found a P0700 (Transmission Control System Malfunction) and a few solenoid circuit codes. From experience, I know that on these vans, the TCM located on the LH strut tower is exposed to significant heat and vibration. These factors often lead to internal solder joint failure. Instead of a full transmission teardown, the first logical step was to address the brain. We installed a VIN-programmed 2006-2009 Montana TCM. After a 20-minute swap and clearing the codes, the van shifted perfectly. It was a simple, effective fix that saved the customer thousands and got their family safely back on the road.
A Straightforward Guide to Installation
- ✔ Safety First: Before you begin, disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the Module: On the 2006-2009 Pontiac Montana, the TCM is typically found bolted to the driver’s side (LH) strut tower in the engine bay. It’s a silver box with electrical connectors.
- ✔ Disconnect and Remove: Carefully unplug the electrical harness connectors. Press the release tabs firmly. Then, remove the bolts or nuts securing the old module to the strut tower.
- ✔ Install the New TCM: Mount your new, pre-programmed TCM in the same location and secure it with the original hardware. Reconnect the electrical harnesses, ensuring they click securely into place.
- ✔ Final Steps: Reconnect the negative battery terminal. While the battery disconnect often clears codes, it’s best practice to use a basic OBD2 scan tool to clear any remaining DTCs from the computer’s memory. Start the vehicle and take it for a test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles. While this page is focused on the 2006-2009 Montana TCM, it is also compatible with the models listed below. Always verify your part number (24235340) or contact us with your VIN to ensure perfect fitment.
- Pontiac Montana (2006-2009): Located at LH strut tower
- Chevrolet Cobalt / Pontiac G5 / Saturn Ion (2006-2010): Located at LH strut tower
- Chevrolet Impala / Monte Carlo / Buick Allure / LaCrosse (2006-2011): Located at lower air cleaner housing
- Chevrolet HHR (2006-2011): Located in LH engine compartment
- GMC Sierra / Chevrolet Silverado (2007-2013): Located next to the battery
- GMC Yukon / Chevrolet Tahoe (2007-2009): Located next to the battery
- And many other GM models from 2006-2014. Please see the full fitment list for details.
Frequently Asked Questions
Do I need to get this module programmed by a dealer?
No. This module comes fully pre-programmed to your vehicle’s VIN. It is ready for installation right out of the box, saving you hundreds of dollars in dealership fees.
Is this a difficult part for a DIY mechanic to install?
Not at all. For most models, including the Pontiac Montana, this is a very straightforward job requiring only basic hand tools. It’s typically located in an accessible spot in the engine bay and takes less than 30 minutes to swap.
Will this fix a P0700 trouble code?
A P0700 code is a general code indicating a fault within the transmission control system. While a failing TCM is a very common cause, you should also check for any other specific codes (like solenoid or sensor codes) to confirm the diagnosis. In many cases, replacing a faulty TCM will resolve the P0700 code.
What is the warranty on this part?
This part comes with a one-year warranty, giving you peace of mind and confidence in your repair.
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 ship it back.