End Your Transmission Headaches and Get Your Buick Terraza Driving Right
If you’re dealing with the frustration of a 2006-2007 Buick Terraza that shifts harshly, gets stuck in gear, or has a persistent check engine light, you know how disruptive it can be. The transmission control module (TCM) is the brain of your automatic transmission, and when it fails, it can make your family minivan feel unreliable and unsafe. This isn’t just an inconvenience; it’s a critical component failure that needs a dependable solution. This T42 TCM, part number 24243921, is the answer, arriving fully programmed to your vehicle’s VIN for a true plug-and-play repair.
A Technician’s Notebook: The Minivan Stuck in Limp Mode
A customer brought in a 2007 Terraza with the classic complaint: “It feels like it’s stuck in one gear and the engine is racing.” A quick scan confirmed my suspicion—a P0700 (Transmission Control System Malfunction) code was present. In my 20+ years of diagnostics, I’ve seen this hundreds of times with these GM T42 modules. Internal circuit board failures from heat cycles and vibration are the typical culprits. Instead of a costly and time-consuming diagnostic rabbit hole, we installed a VIN-programmed module. The result? Codes cleared, shift patterns returned to normal, and the customer was back on the road in less than an hour, having avoided a trip to the dealership. This part is a direct fix for these exact issues.
Is Your Buick Terraza Showing These Transmission Issues?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, it’s highly likely that your 2006-2007 Terraza TCM is the source of the problem. Ignoring these can lead to more significant transmission damage down the line.
- ✔ Abrupt, harsh, or jerky gear shifts.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ Vehicle is stuck in “limp mode” (usually 2nd or 3rd gear).
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750-P0758 (solenoid codes), or other transmission-related faults.
- ✔ Poor acceleration and a noticeable drop in fuel economy.
- ✔ Inconsistent shifting or complete failure to shift up or down.
DIY Installation: Get Your Terraza Shifting Smoothly in Under 30 Minutes
One of the best features of this module is that it’s designed for a straightforward installation, saving you hundreds in labor costs. You don’t need to be a master mechanic to get this job done. For your Terraza, the TCM is easy to access.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and to help reset the system.
- Locate the Module: On the 2006-2007 Buick Terraza, the TCM is located at the driver’s side (LH) strut tower in the engine compartment. It’s a black box with electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harnesses. They have locking tabs, so be gentle. Then, unbolt the old module from its mounting bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place and securely reconnect the wiring harnesses. You should hear a click as they lock in.
- Final Steps: Reconnect the battery terminal. Start the vehicle and allow it to idle for a few minutes. If you have a basic OBD2 scanner, it’s a good practice to clear any stored fault codes.
Verified Fitment for Your Vehicle
This T42 Transmission Control Module is the correct replacement for your minivan and is also compatible with a wide range of other General Motors vehicles. It is a direct replacement for part number 24243921 and other service numbers like 24234503 and 24252114.
Primary Application:
- Buick Terraza: 2006-2007 (Transmission; located at LH strut tower)
This part also fits models like the Chevrolet Uplander, Pontiac Montana, Saturn Relay, and many other GM cars, trucks, and SUVs that use the T42 controller. By providing your VIN at checkout, we ensure it’s programmed with the latest GM software specifically for your vehicle’s configuration.
Frequently Asked Questions
What does ‘VIN Programmed’ actually mean?
It means we load the module with your vehicle’s specific Vehicle Identification Number (VIN) and the latest factory software before shipping. This ensures it communicates perfectly with your engine computer and other systems right out of the box, eliminating the need for an expensive dealership visit for programming.
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 TCM itself is the source of the failure, replacing it with this pre-programmed unit is the direct and proper repair to clear the code and resolve the underlying issue.
Do I need any special tools for this installation?
No special tools are required. Basic hand tools, such as a socket set and a wrench for the battery terminal, are all you should need to complete the job in your driveway.
Is there a core charge for my old part?
No, there is absolutely no core charge. You can keep your old part or dispose of it without the hassle of shipping it back, making the process simpler and more convenient for you.