Is your 2006-2009 Pontiac Montana suffering from frustrating and unsafe transmission problems? If you’re dealing with sudden harsh shifts, getting stuck in gear, or seeing that dreaded check engine light, you’re not alone. The Transmission Control Module (TCM) is the brain of your automatic transmission, and when it fails, it can make your family’s daily driver feel unreliable. This is a direct-fit, VIN-programmed T42 TCM, designed to solve these issues and restore the smooth, predictable performance your minivan needs.
As a technician with over two decades of experience, I’ve seen countless GM vehicles, including the Montana, come into the shop with these exact symptoms. The cause is often a failing original TCM. This replacement module, part number 24230461, is the definitive solution. We pre-program it to your vehicle’s specific VIN before shipping, which means it arrives ready for a true plug-and-play installation. You get to skip the expensive and time-consuming trip to the dealership for programming—a savings of both time and money.
Is Your Minivan’s TCM Failing? Common Symptoms to Watch For
- ✔ Harsh, clunky, or erratic gear shifts that make driving uncomfortable.
- ✔ The vehicle gets stuck in “limp mode,” often refusing to shift out of 2nd or 3rd gear.
- ✔ An illuminated Check Engine Light or Transmission Warning Light, commonly with Diagnostic Trouble Codes (DTCs) like P0700 (Transmission Control System Malfunction) or various solenoid codes (P0750-P0774).
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable decrease in fuel economy as the transmission operates inefficiently.
- ✔ Complete failure to shift gears, leaving you stranded.
Case Study: A Tricky Diagnosis
A customer brought in their 2008 Montana, explaining that it would randomly slam into gear and occasionally wouldn’t shift past 2nd. They had already replaced a shift solenoid with no luck. After a quick scan, I saw the tell-tale P0700 code. Instead of just throwing more parts at it, we checked the TCM connector for corrosion—it was clean. This pointed directly to an internal failure in the module itself. We installed one of our pre-programmed TCMs, and the van was shifting perfectly within 30 minutes. The customer was thrilled to avoid a costly dealership bill and have their family vehicle back on the road safely.
A Straightforward Guide to Installation
One of the best features of this repair is its simplicity, making it a perfect job for a DIYer. For the 2006-2009 Pontiac Montana, the TCM is conveniently located on the driver’s side strut tower in the engine bay. You can have this swapped out in under half an hour.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the Module: Open the hood and find the TCM mounted to the LH (driver’s side) strut tower. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical harnesses. Then, unbolt the module from its mounting bracket.
- Install the New TCM: Mount the new, pre-programmed TCM in the same location and securely reconnect the wiring 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 scanner to clear any stored fault codes from the previous failure.
Will This Fit My Vehicle?
This T42 Transmission Control Module is a reliable replacement for a wide range of General Motors vehicles. While it is the correct part for your 2006-2009 Montana TCM repair, it also fits many other cars, trucks, and SUVs. It is a direct replacement for part numbers including 24252114, 24234503, 24230461, 24234274, and others. Please verify your vehicle in the list below:
- 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 1500/2500 (2007-2013) – Transmission; (next to battery)
- GMC Sierra 1500/2500 (2007-2013) – Transmission; (next to battery)
- Buick LaCrosse / Allure (2006-2009) – Transmission; (lower air cleaner housing)
- Saturn Vue (2007-2010) – Transmission; (LH front engine compartment)
- …and many more models listed in the full compatibility chart.
Frequently Asked Questions
Frequently Asked Questions
Do I need to take my van to the dealer after installing this TCM?
No. This module is fully pre-programmed to your vehicle’s VIN before it ships. This eliminates the need for any additional programming or calibration at a dealership, making it a true plug-and-play solution.
What is the main benefit of VIN programming?
VIN programming ensures the module has the correct software and settings specifically for your vehicle’s configuration (engine, transmission, options). This guarantees optimal shift patterns, fuel efficiency, and seamless communication with other vehicle computers right out of the box.
Is this part number 24230461 the only one it replaces?
No, this module is interchangeable with a wide range of GM service numbers, including 24252114, 24234503, 24242391, and many others. It’s designed to be a comprehensive solution for the T42 TCM platform.
Do I need to send my old TCM back (core charge)?
There is no core charge for this part. You can keep your old module or dispose of it responsibly without any extra hassle or fees.
Will this fix a P0700 code?
In many cases, yes. A P0700 code indicates a general fault in the transmission control system, and a failing TCM is one of the most common root causes. Replacing a faulty TCM with this programmed unit will typically resolve the issue and allow the code to be cleared.