If your 2006-2007 Buick Rainier is suffering from erratic shifting, getting stuck in gear, or throwing transmission codes, the culprit is often a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a faulty TCM can make your reliable SUV feel unpredictable and unsafe. This T42 series TCM, part number 24243901, is the definitive solution, arriving expertly programmed to your vehicle’s VIN for a true plug-and-play repair that restores the smooth, responsive performance you expect.
From the Diagnostic Bay
I remember a 2007 Rainier that came into the shop with a classic case of what the owner called ‘transmission confusion.’ It would shift hard from 1st to 2nd when cold, but then occasionally refuse to downshift at a stoplight. He was getting a generic P0700 code, and another shop had already replaced two shift solenoids without success. After confirming the solenoids were receiving incorrect voltage commands, we identified the TCM as the root cause. These T42 modules, especially after years of heat cycles in the engine bay, can develop internal circuit failures. Swapping in a VIN-programmed module like this one solved the problem in under 20 minutes. The customer was thrilled to avoid a costly trip to the dealership for programming and finally have his vehicle driving correctly.
Is Your Buick Exhibiting These Transmission Woes?
A failing TCM sends clear warning signs. If you’re experiencing any of the following, it’s time to consider a replacement. This is especially true if you’ve scanned for codes and found DTCs like P0700, P0750, P0753, or other solenoid-related faults.
- ✔ Harsh, banging, or delayed gear shifts.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ The Check Engine Light or a specific transmission warning light is illuminated.
- ✔ Inconsistent upshifting or downshifting, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy.
- ✔ Complete loss of communication with the transmission.
The Power of Pre-Programmed Precision for your 2006-2007 Rainier TCM
The single biggest hurdle in replacing a modern electronic module is programming. Dealerships often charge hundreds for this service alone. Our process eliminates that step entirely. We flash this module with the latest GM software calibrated specifically to your Buick Rainier’s VIN. This ensures that all shift points, torque converter lockup strategies, and diagnostic parameters are perfectly matched to your vehicle’s factory settings. The result is a seamless installation that restores OEM functionality without any extra cost or hassle.
A Straightforward Guide to Installation
For the average DIYer, this is a very manageable job that typically takes less than 30 minutes. The TCM on the 2006-2007 Rainier is located in the engine compartment. No complex tools are required.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the Module: On the Rainier, the TCM is typically found in the engine compartment. Check for a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place. Securely reconnect the electrical harnesses, ensuring 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 initial failure. Start the vehicle and enjoy your smooth-shifting transmission!
Verified Vehicle Compatibility
While this is the correct part for the 2006-2007 Buick Rainier, this T42 TCM is also a direct replacement for a wide range of other General Motors vehicles. It interchanges with part numbers 24252114, 24234503, 24230461, and more. Please verify your part number or contact us to confirm fitment for models including:
- Buick Allure, LaCrosse, Lucerne, Rainier, Rendezvous
- Cadillac DTS
- Chevrolet Avalanche, Cobalt, Colorado, Express, HHR, Impala, Malibu, Monte Carlo, Silverado, SSR, Suburban, Tahoe, Trailblazer
- GMC Canyon, Envoy, Savana, Sierra, Yukon
- Hummer H3
- Pontiac G5, G6, Grand Prix, Pursuit
- Saab 9-7X
- Saturn Aura, Ion, Vue
Frequently Asked Questions
Why is VIN programming so important for a TCM?
VIN programming loads your vehicle’s specific software for shift points, engine parameters, and options. Without it, a generic module won’t communicate correctly with your vehicle’s other computers, leading to poor performance or a no-start condition. Our pre-programming saves you a mandatory, expensive trip to the dealer.
Is this a difficult part to install myself?
Not at all. For most DIYers with basic hand tools, this is a simple, sub-30-minute job. The module is easily accessible in the engine bay, requiring only unbolting the old unit and plugging in the new one.
Will this module fix my P0700 transmission code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While this module often resolves the root cause (like failed internal drivers for solenoids that trigger the P0700), you should always diagnose the specific secondary codes (e.g., P0753) to be certain. In many cases, a faulty TCM is the culprit.
Where is the TCM located on my 2006 Buick Rainier?
On the 2006-2007 Buick Rainier, as well as its sister vehicles like the Trailblazer and Envoy, the Transmission Control Module is located in the engine compartment, typically on the driver’s side (LH).
Do I need to send my old TCM back?
No, there is no core charge for this part. You can keep your old module, which simplifies the process and gets your vehicle back on the road faster.