If your 2006 or 2007 Chevrolet Monte Carlo is experiencing unpredictable shifting, getting stuck in gear, or has the check engine light glaring at you, the problem often points directly to a failing Transmission Control Module (TCM). As an automotive diagnostician with over two decades of experience, I’ve seen how a faulty TCM can sideline an otherwise great car. This isn’t just an inconvenience; it’s a critical failure that affects performance, fuel economy, and safety. This T42 TCM, part number 24235754, is the definitive, reliable solution to get your Monte Carlo’s transmission operating with factory precision once again.
Case Study: The Ghost in the Transmission
A customer brought in a 2007 Monte Carlo with a frustrating intermittent issue. It would shift perfectly for days, then suddenly slam into gear or refuse to shift out of 2nd. They had already replaced a shift solenoid based on a code, but the problem returned. After hooking up my scan tool and monitoring live data, I saw the TCM was intermittently dropping communication. This is a classic sign of internal circuit board failure, often caused by years of heat cycles. We installed one of our VIN-programmed T42 modules, and the problem was solved permanently. The key was that the module itself was the root cause, not just the codes it was throwing.
Diagnosing a Faulty Monte Carlo TCM
A failing TCM doesn’t always mean a complete transmission shutdown. It often starts with subtle signs that can be mistaken for other issues. If you’re a DIYer trying to pinpoint the problem or a professional mechanic confirming a diagnosis, here are the tell-tale symptoms I’ve seen hundreds of times in the shop.
- ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle is stuck in “limp mode,” usually in 2nd or 3rd gear, with no upshifting or downshifting.
- ✔ Check Engine Light or Transmission Warning Light is on, with Diagnostic Trouble Codes (DTCs) like P0700 (Transmission Control System Malfunction), P0750, or other solenoid-related faults.
- ✔ A noticeable decrease in fuel efficiency as the transmission isn’t shifting at the optimal points.
- ✔ Complete loss of communication with the TCM, preventing diagnostics and causing total transmission failure.
A Straightforward Guide to Installation
One of the best features of this part is its simple, plug-and-play installation. Because we program it to your vehicle’s VIN before shipping, you can avoid a costly and time-consuming trip to the dealership. For the 2006-2007 Monte Carlo, the process is very accessible.
- Safety First: Always disconnect the negative terminal on your vehicle’s battery before starting any electronic component replacement.
- Locate the Module: On your Monte Carlo, the TCM is typically found under the lower air cleaner housing. You will need to remove the airbox assembly to gain access.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old TCM. 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 connectors. You should hear a click as they lock in.
- Final Steps: Reinstall the air cleaner housing and reconnect the battery. While the battery disconnect often clears codes, it’s good practice to use a basic scan tool to clear any stored DTCs. Start the car and enjoy smooth shifting!
Will This Fit My Vehicle?
This T42 Transmission Control Module is the correct, direct-fit replacement for the following vehicle:
- Chevrolet Monte Carlo (2006-2007) – Located under the lower air cleaner housing.
This module also fits a wide range of other GM vehicles from 2006-2014, including the Impala, Grand Prix, LaCrosse, and more, making it a proven and reliable component across the GM family. It is a direct replacement for part numbers 24252114, 24234503, 24235754, 24240449, and others.
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. We pre-program the module to your vehicle’s specific VIN before it ships. This means it is ready for installation right out of the box, with no additional programming or dealer visits required.
What is the warranty on this part?
This module comes with a one-year, hassle-free warranty, giving you peace of mind and confidence in your repair.
Is a core charge required?
No, there is no core charge. You can keep your old part, so you don’t have to worry about the cost or hassle of shipping it back.
Will this fix a P0700 trouble code?
A P0700 code is a general fault request from the TCM to the ECM. While this module often resolves the root cause of the P0700 code (like an internal TCM failure or a bad solenoid driver), you should always diagnose any other codes that appear alongside it.
How difficult is the installation for a DIYer?
For most DIYers with basic tools, this is a straightforward job that can be completed in under an hour. The primary task is removing the air cleaner box to access the module.