Restore Crisp, Reliable Shifting to Your 2006-2007 Buick Rainier
If your Buick Rainier is suffering from harsh shifting, delayed gear engagement, or is stuck in limp mode, a failing Transmission Control Module (TCM) is the most likely culprit. As a technician with over two decades of experience, I’ve seen these T42-style modules cause some of the most frustrating and misdiagnosed transmission issues on GM vehicles. This isn’t just a replacement part; it’s a direct solution to get your vehicle’s transmission computer communicating correctly again, restoring the smooth performance you expect.
This module, part number 24235754, comes pre-programmed to your vehicle’s specific VIN. This is a critical step that many overlook. Without correct programming, the module won’t know your vehicle’s specific build, leading to continued errors. We handle the programming for you, so you can skip the expensive trip to the dealership and install it right out of the box. It’s the definitive fix for common diagnostic trouble codes (DTCs) like P0700 and various solenoid performance codes that point to an internal TCM failure.
From the Diagnostic Bay: The Rainier That Baffled a Shop
A customer brought in a 2007 Buick Rainier that was shifting hard from 1st to 2nd and occasionally throwing a generic P0700 transmission fault code. Another shop had already replaced two shift solenoids, but the problem persisted. After connecting my scan tool, I noticed the live data for line pressure was erratic. Instead of chasing mechanical ghosts, I went straight for the TCM. Once we swapped in a VIN-programmed module, the line pressure stabilized instantly, and the harsh shifts vanished. It’s a classic case where the ‘brain’ was the problem, not the ‘body’—a lesson that saved the customer hundreds in unnecessary labor and parts.
Is Your Buick Exhibiting These Telltale Signs?
A faulty 2006-2007 Rainier TCM can manifest in several ways. If you’re experiencing any of the following, it’s time to consider a replacement:
- ✔ Abrupt, jerky, or unpredictable gear changes.
- ✔ The transmission refuses to shift out of a single gear (often 2nd or 3rd).
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750, P0753, P0758.
- ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
- ✔ The vehicle feels sluggish or like it’s slipping between gears.
- ✔ Complete loss of communication with the transmission module.
Your 30-Minute Path to Smoother Shifting
Installation is a straightforward job for any DIY enthusiast or professional mechanic. No complex procedures or special tools are needed.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts and help reset the system.
- Locate the Module: On the 2006-2007 Buick Rainier, the TCM is typically found in the engine compartment. Check common GM locations like next to the battery, under the air cleaner box, or on the driver-side strut tower.
- Disconnect and Remove: Carefully unplug the electrical connectors. Press the release tabs firmly to avoid damaging them. Then, unbolt the old module from its mounting bracket.
- Install the New TCM: Mount your new, pre-programmed module in the same location and securely fasten it. Reconnect the electrical harnesses until they click into place.
- Final Steps: Reconnect the battery terminal. While our programming resolves most codes, it’s good practice to use a basic OBD2 scanner to clear any stored DTCs from the ECU. Start the vehicle and take it for a test drive to confirm smooth operation.
Confirmed Vehicle Compatibility List
This T42 Transmission Control Module is a direct fit for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E. While this page is focused on the 2006-2007 Rainier TCM, it is also compatible with the following models. Please verify your specific model and part number.
- ✔ Buick: Rainier (06-07), LaCrosse (06-09), Lucerne (06-11), Allure (06-09), Rendezvous (06-07), Terraza (06-07)
- ✔ Chevrolet: Silverado, Tahoe, Suburban, Avalanche (07-13), Express Van (06-14), Impala (06-11), Monte Carlo (06-07), Cobalt (06-10), HHR (06-11), Colorado (08-12), SSR (05-06), Malibu (06-10)
- ✔ GMC: Sierra, Yukon, Savana Van (06-14), Envoy (06-09), Canyon (08-12)
- ✔ Pontiac: G6 (06-10), Grand Prix (06-08), G5 (07-10), Pursuit (06), Montana (06-09)
- ✔ Cadillac: DTS (06-11)
- ✔ Hummer: H3 (08-10)
- ✔ Saab: 9-7X (06-09)
- ✔ Saturn: Vue (07-10), Aura (07-09), Ion (06-07)
This module is interchangeable with part numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24238856, 24239224, 24240400, 24256960, and more.
Frequently Asked Questions
Do I need to take my car to the dealer after installation?
No. This module comes fully programmed to your vehicle’s VIN. It is a true plug-and-play solution, saving you the time and expense of a dealership visit for programming.
Is this part difficult to install for a DIYer?
Not at all. With basic hand tools, the replacement typically takes less than 30 minutes. The module is located in the engine bay for easy access. Just disconnect the battery, swap the modules, and reconnect everything.
What is a core charge?
A core charge is a deposit you pay until you return your old part. We do not require a core charge for this module, so you can keep your old part without any hassle or extra cost.
Will this fix a P0700 trouble code?
Yes, in many cases. The P0700 code is a general fault code indicating the TCM has detected a problem. If the root cause is an internal failure of the TCM itself, replacing it with our pre-programmed unit will resolve the code.
What kind of warranty is included?
We stand behind the quality of our electronics. This transmission control module is backed by a one-year warranty, giving you peace of mind for your repair.