Restore Smooth Shifting to Your Pontiac Montana
If your 2006-2009 Pontiac Montana is suffering from harsh shifting, getting stuck in gear, or throwing transmission-related check engine light codes, you’re not alone. After 20 years of diagnosing these vehicles, I’ve seen countless T42 Transmission Control Modules (TCMs) cause these exact headaches. This VIN-programmed T42 TCM, part number 24243901, is the definitive solution to restore your minivan’s factory performance and reliability without an expensive trip to the dealership.
A Technician’s Notebook
I recently had a 2008 Montana in the bay that was driving the owner crazy. It would shift perfectly fine when cold, but after 15 minutes of driving, it would slam into gear and eventually get stuck in 3rd (limp mode). The scanner showed a generic P0700 code. Instead of chasing solenoids inside the transmission, experience pointed me straight to the TCM. Heat soak was causing an internal failure. We swapped in one of these pre-programmed modules, and the van was shifting like new in under an hour. It’s a classic failure on these platforms, and this part is the most reliable fix.
Is Your Montana Showing These Signs of TCM Failure?
A failing TCM can manifest in several ways, often getting worse over time. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement. A faulty 2006-2009 Montana TCM is a common issue that we see frequently.
- ✔ Harsh, erratic, or delayed gear shifts.
- ✔ Vehicle is stuck in “limp mode” and won’t shift out of 2nd or 3rd gear.
- ✔ The Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-specific codes.
- ✔ A sudden drop in fuel economy.
- ✔ The transmission seems to slip or fails to engage a gear properly.
Quick & Easy DIY Installation Guide
One of the best parts about this module is its straightforward installation. You don’t need a professional lift or specialized transmission tools. For the Pontiac Montana, the process is particularly simple.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the TCM: On your 2006-2009 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 from the old module. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s good practice to use a basic OBD2 scan tool to clear any stored fault codes from the vehicle’s memory.
Verified Fitment for Your GM Vehicle
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 the location noted for your specific vehicle.
- Pontiac Montana (2006-2009): Transmission; (LH strut tower)
- Chevrolet Cobalt (2006-2010): Transmission; (LH strut tower)
- Chevrolet HHR (2006-2011): Transmission; (LH engine compartment)
- Chevrolet Impala (2006-2011): Transmission; (lower air cleaner housing)
- Chevrolet Silverado 1500 (2007-2013): Transmission; (next to battery)
- GMC Sierra 1500 (2007-2013): Transmission; (next to battery)
- Buick LaCrosse (2006-2009): Transmission; (lower air cleaner housing)
- Pontiac G6 (2006-2010): Transmission; (LH strut tower)
- And many more GM cars, trucks, and SUVs. See full list for details.
Frequently Asked Questions
What exactly is VIN programming?
VIN programming means we load your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This ensures it communicates perfectly with your engine computer and other systems right out of the box, eliminating the need for a costly programming service at a dealership.
Do I need to send my old part back?
No. There is absolutely no core charge or need to return your old, faulty module. You can dispose of it or keep it, making the replacement process faster and more convenient for you.
Is this a difficult part for a DIYer to install?
Not at all. For the Pontiac Montana, this is one of the easier electronic components to replace. It’s located right on the driver’s side strut tower and requires only basic hand tools. Most of our customers complete the job in under 30 minutes.
Will this fix a P0700 trouble code?
Yes, in many cases. The P0700 code is a general transmission fault request, meaning the TCM has detected a problem and asked the main computer to turn on the check engine light. If the underlying issue is a failing TCM, replacing it with this module will resolve the cause of the P0700 code.
What kind of warranty is included?
We stand behind our products with a comprehensive one-year warranty. This gives you peace of mind that you’re installing a quality, dependable part built to meet or exceed OEM specifications for long-lasting performance.