If your 2006-2007 Buick Rainier is suffering from erratic shifting, getting stuck in gear, or has thrown a Check Engine Light with transmission codes, you’ve come to the right place. As a technician with over two decades of experience, I’ve seen firsthand how a failing Transmission Control Module (TCM) can turn a reliable SUV into a source of constant frustration. This isn’t just an inconvenience; it’s a critical component failure that compromises performance and safety. This VIN-programmed T42 Transmission Control Module is the direct-fit, reliable solution to restore your vehicle’s factory performance without a costly trip to the dealership.
This module is the brain of your automatic transmission, precisely managing shift points, torque converter clutch engagement, and line pressure. When it fails, the symptoms are often misdiagnosed as internal transmission damage, leading to expensive and unnecessary repairs. Our module, compatible with part number 24240449, arrives pre-programmed to your Rainier’s specific Vehicle Identification Number (VIN). This means no additional programming or flashing is required. It’s a true plug-and-play fix that gets you back on the road with confidence.
Case Study: A Tricky Diagnosis
A customer brought in their ’07 Buick Rainier with classic symptoms: harsh 1-2 shifts and occasionally getting stuck in 3rd gear (limp mode), especially after it warmed up. The dash was lit up with a P0700 (Transmission Control System Malfunction) code. A less experienced tech might jump to rebuilding the transmission, but my scan tool showed intermittent communication loss with the TCM. After swapping in one of our pre-programmed T42 modules—a 20-minute job—the codes cleared, the communication was stable, and the Rainier shifted as smoothly as it did the day it left the factory. This simple part saved the customer thousands.
Is Your Buick Rainier Showing These Symptoms?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, a faulty module is the likely culprit:
- âś” Harsh, delayed, or unpredictable gear shifts.
- âś” Vehicle is stuck in “limp mode” and will not shift out of 2nd or 3rd gear.
- âś” Check Engine Light or Transmission Warning Light is on with codes like P0700, P0753, P0758, or other solenoid-related faults.
- âś” A complete loss of shifting ability, either up or down.
- âś” Poor fuel economy and a feeling of sluggish performance.
- âś” No communication with the TCM when using a diagnostic scan tool.
A Straightforward Guide to Your 2006-2007 Rainier TCM Installation
Replacing the TCM on your Rainier is a simple job that most DIYers can handle in their own driveway in under 30 minutes. The module is typically located in the engine compartment for easy access.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On the 2006-2007 Rainier, the TCM is found in the engine compartment. Check common GM locations like next to the battery, under the air cleaner box, or on a strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors. Use a small screwdriver to gently release the locking tabs if needed. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place and securely reconnect the electrical harnesses. You should hear a ‘click’ as they lock.
- Final Steps: Reconnect the battery terminal. Start the vehicle and use a basic OBD2 scan tool to clear any stored diagnostic trouble codes (DTCs). Take the vehicle for a test drive to confirm smooth shifting.
Guaranteed Vehicle Compatibility
This module is a direct replacement for part number 24240449 and is guaranteed to fit your 2006-2007 Buick Rainier. It is also a compatible replacement for a wide range of other GM vehicles that use the T42 TCM, including models from Chevrolet, GMC, Pontiac, Saturn, and more. Please verify your part number or contact our expert support team to ensure a perfect fit.
Frequently Asked Questions
Frequently Asked Questions
Do I need to take my vehicle to a dealer for programming?
No. This module comes fully pre-programmed to your vehicle’s VIN. It is a plug-and-play solution, saving you the time and expense of a dealership visit.
What is a T42 TCM?
The T42 is a specific generation of Transmission Control Module used by General Motors in many of its 4-speed automatic transmissions, like the 4L60E and 4L65E, during the mid-2000s and beyond.
Will this fix a P0700 code on my Rainier?
A P0700 is a general code indicating a fault has been stored in the TCM. In many cases where the TCM itself has failed internally or has communication issues, replacing it with this module will resolve the root cause of the P0700 code.
Is this a difficult part to install myself?
Not at all. For most DIY enthusiasts with basic hand tools, this is a very straightforward installation that typically takes less than 30 minutes. The module is easily accessible in the engine bay.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old module without any extra hassle or fees.