If your 2006-2007 Buick Rainier is suffering from erratic shifting, getting stuck in gear, or throwing transmission-related codes, the culprit is often a failing Transmission Control Module (TCM). As a seasoned technician, I’ve seen firsthand how a faulty TCM can sideline an otherwise reliable vehicle. This T42 Transmission Control Module, corresponding to part number 24238856, is the definitive solution to restore your vehicle’s transmission performance and drivability.
The TCM is the electronic brain of your automatic transmission, responsible for managing every gear change, controlling torque converter lockup, and monitoring system health. When it fails, the symptoms can range from annoying to dangerous. This replacement module is meticulously prepared and programmed to your vehicle’s specific VIN, ensuring it works perfectly right out of the box. No expensive trips to the dealership for programming are necessary, saving you time and money.
Case Study: A Tricky Diagnosis
A customer brought in a 2006 Buick Rainier with a classic complaint: intermittent harsh shifting and the transmission light flickering on the dash. He’d already replaced a couple of solenoids with no luck. A quick scan showed a P0700 (Transmission Control System Malfunction) and a U0101 (Lost Communication with TCM). Instead of chasing ghosts in the wiring, we inspected the TCM. After seeing some minor corrosion on the case, we knew where the problem was. We installed one of our VIN-programmed T42 modules, and the vehicle was shifting like new in under an hour. This is a common failure, and this module is the direct, reliable fix.
Is Your Rainier Exhibiting These Transmission Problems?
A failing TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement. Addressing it promptly can prevent further damage to your transmission.
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ The Check Engine Light or a dedicated transmission warning light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related faults.
- ✔ Complete failure to shift up or down.
- ✔ A noticeable drop in fuel economy.
- ✔ Intermittent loss of communication with the module.
Solving Transmission Issues with a 2006-2007 Rainier Transmission Control Module
Choosing our pre-programmed TCM means you’re getting a part that is ready for immediate installation. We handle the complex programming process using the latest GM software updates, so you can perform the repair with confidence, whether you’re a DIY enthusiast or a professional mechanic. This ensures optimal shift points, fuel efficiency, and communication with your vehicle’s other electronic systems.
A Straightforward Guide to Installation
Replacing the TCM on your Buick Rainier is a job you can do in your own garage. It’s 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 for a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the electrical wiring harnesses from the old TCM. Then, unbolt the module from its mounting bracket.
- Install the New Module: Mount the new VIN-programmed TCM in place and securely fasten the bolts. Reconnect the wiring 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 scan tool to clear any stored DTCs from the vehicle’s memory.
Verified Vehicle Compatibility
This T42 Transmission Control Module (part number 24238856 and its interchanges) is the correct fit for the following vehicles and configurations:
- BUICK RAINIER: 2006-2007
- CHEVROLET: Avalanche 1500 (07-08), Cobalt (06-10), Colorado (08-12), Express 1500/2500/3500 Van (06-14), HHR (06-11), Impala (06-11), Monte Carlo (06-07), Silverado 1500/2500 (07-13), SSR (05-06), Suburban 1500 (07-08), Tahoe (07-09), Trailblazer & EXT (06-09)
- GMC: Canyon (08-12), Envoy & XL (06-09), Savana 1500/2500/3500 Van (06-14), Sierra 1500/2500 (07-13), Yukon & XL 1500 (07-09)
- BUICK: Allure (06-09), LaCrosse (06-09), Lucerne (06-11), Rendezvous (06-07)
- CADILLAC: DTS (06-11)
- HUMMER: H3 (08-10)
- PONTIAC: G5 (07-10), G6 (06-10), Grand Prix (06-08), Pursuit (06), Montana (06-09), Terraza (06-07), Uplander (06-09)
- SAAB: 9-7X (06-09)
- SATURN: Aura (07-09), Ion (06-07), Vue (07-10)
Note: Always verify your part number (24238856 or an interchange like 24242391, 24234503, 24252114) to ensure a perfect match.
Frequently Asked Questions (FAQ)
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean for me?
It means we load your vehicle’s unique Vehicle Identification Number (VIN) and the latest GM software onto the module before we ship it. This makes it a true plug-and-play part, as it’s already calibrated for your specific Rainier, eliminating the need for a dealership visit.
Do I need any special tools for this installation?
No special tools are required. Basic hand tools like a socket set will be sufficient for removing the old module and installing the new one. A code scanner is helpful for clearing old codes but not mandatory for the part to function.
Is there a core charge for my old TCM?
No, there is no core charge. You can keep your old part or dispose of it without the hassle of sending it back to us.
Will this fix a P0700 trouble 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 internal failure), it’s important to ensure there are no other issues, such as faulty wiring or solenoids. In many cases I’ve diagnosed, a new TCM is the correct fix.
How do I provide my VIN?
You will be prompted to enter your vehicle’s 17-digit VIN during the checkout process. Please double-check it for accuracy to ensure correct programming.