If your 2006-2007 Buick Rainier is suffering from harsh shifting, getting stuck in gear, or throwing transmission codes, you’ve likely pinpointed the culprit: a failing Transmission Control Module (TCM). As a technician with over two decades of experience, I’ve seen countless GM vehicles sidelined by faulty TCMs. This isn’t just an annoyance; it’s a critical failure that can affect your vehicle’s drivability and safety. This T42 series TCM, part number YNXS, is the definitive, reliable solution, pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
A Technician’s Notebook: The Intermittent Rainier
A customer brought in a 2007 Buick Rainier with a frustrating problem. It would drive perfectly for days, then suddenly start slamming into gear and refuse to shift past 3rd. They’d already replaced a shift solenoid with no luck. After connecting my scan tool, I saw a generic P0700 code but no hard solenoid faults. Experience pointed me to the TCM. Heat soak and internal vibrations can cause intermittent connection failures inside these modules. We installed one of our VIN-programmed TCMs, and the problem was solved instantly. It’s a classic case where chasing individual codes can be misleading; the root cause is often the brain controlling the system.
Is Your Buick Rainier Exhibiting These Transmission Woes?
A failing TCM sends clear signals. If you’re noticing any of the following, it’s time for a replacement. Ignoring these can lead to more significant transmission damage down the road.
- ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- ✔ The vehicle is stuck in “limp mode,” often locked in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is on with codes like P0700 (Transmission Control System Malfunction), P0750-P0758 (Shift Solenoid Faults), or other communication errors.
- ✔ Complete failure to upshift or downshift, leading to poor acceleration and high RPMs.
- ✔ A noticeable drop in fuel economy as the transmission operates inefficiently.
- ✔ Intermittent loss of communication with the module, causing unpredictable behavior.
The Direct Solution: A Pre-Programmed 2006-2007 Rainier TCM
This isn’t just a replacement part; it’s a complete solution. The biggest hurdle with electronic modules is the need for expensive dealership programming. We eliminate that step entirely. By programming this module to your Rainier’s VIN before it ships, we ensure it communicates flawlessly with your vehicle’s Powertrain Control Module (PCM) and other systems right out of the box. This restores the precise electronic control over shift points, torque converter lockup, and line pressure that your transmission needs to perform as it did from the factory.
Your Straightforward 30-Minute Installation Guide
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the onboard systems.
- ✔ Locate the TCM: On the 2006-2007 Buick Rainier, the TCM is typically found in the engine compartment. Check the driver’s side (LH) of the engine bay.
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors from the old module. Press the release tabs firmly. Then, unbolt the module from its mounting bracket.
- ✔ Install the New Module: Bolt the new, VIN-programmed TCM into place. Securely reconnect the electrical harnesses, ensuring they click into place to confirm a solid connection.
- ✔ Final Steps: Reconnect the battery terminal. While the system may reset, it’s best practice to use a standard OBD-II scan tool to clear any stored diagnostic trouble codes (DTCs) from the computer’s memory. Start the vehicle and test drive to confirm smooth shifting.
Verified Fitment for Your Vehicle
This module is a direct replacement for your 2006-2007 Buick Rainier. While it is also compatible with a wide range of other GM vehicles, it has been specifically verified for the following models and configurations. It is interchangeable with part numbers 24252114, 24234503, 24230461, and YNXS among others.
- Buick Rainier: 2006-2007
- Chevrolet Trailblazer: 2006-2009 (V8 Models)
- GMC Envoy: 2006-2009 (V8 Models)
- Saab 9-7X: 2006-2009
- …and many other GM cars, trucks, and SUVs from 2006-2014. Please verify your part number.
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
No. This is the biggest benefit of our service. We pre-program the module to your vehicle’s VIN before shipping. It arrives ready for plug-and-play installation, saving you the time and expense of a dealership visit.
What information do you need from me?
We require your vehicle’s 17-digit Vehicle Identification Number (VIN) at checkout. This is essential for us to load the correct GM software and ensure perfect compatibility with your 2006-2007 Rainier.
Is this a difficult part for a DIY mechanic to install?
Not at all. For most DIYers with basic hand tools (like a socket set), this is a straightforward job that can be completed in under 30 minutes. The module is easily accessible in the engine bay.
Will this fix a P0700 check engine light code?
Yes, in most cases. The P0700 code is a general fault code indicating the TCM has detected a problem. If the TCM itself is the source of the failure, replacing it with this new module will resolve the root cause and allow the code to be cleared.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old part or dispose of it without the hassle of shipping it back, simplifying the repair process for you.