If your 2006-2007 Buick Terraza is suffering from erratic shifting, getting stuck in gear, or has an illuminated check engine light, you’re likely dealing with a failing Transmission Control Module (TCM). As a seasoned technician, I’ve seen countless GM vehicles, including the Terraza, sidelined by these exact issues. This isn’t just an annoyance; it’s a critical failure that compromises your vehicle’s reliability and safety. This replacement T42 TCM, part number 24234274, is the definitive, hassle-free solution to restore your minivan’s smooth and predictable performance.
The core of the problem often lies in the original module’s inability to properly communicate commands to the transmission’s solenoids. Our solution is a high-quality replacement 2006-2007 Terraza Transmission Control Module that comes pre-programmed to your vehicle’s specific VIN. This means no expensive trips to the dealership for programming—it’s a true plug-and-play fix that you can perform right in your own driveway.
From the Diagnostic Bay
I remember a customer bringing in their ’07 Terraza. The complaint was intermittent but severe: sometimes it would shift perfectly, other times it would slam into gear or refuse to shift past 2nd. They had already replaced a shift solenoid with no luck. After connecting my scan tool, I saw the tell-tale P0700 (Transmission Control System Malfunction) code. Experience pointed directly to the TCM. We installed one of these VIN-programmed modules, and the vehicle drove out of the bay shifting like it was new. It’s a common failure, and this part is the reliable fix.
Is Your Terraza Showing These Transmission Warning Signs?
A faulty TCM can manifest in several ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement:
- ✔ Harsh, slamming, or delayed gear shifts.
- ✔ The vehicle is stuck in “limp mode” (usually second or third gear).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, such as P0700, P0750, or other solenoid-related codes.
- ✔ A sudden drop in fuel economy.
- ✔ The transmission seems to slip out of gear or fails to engage from Park.
A Straightforward Guide to Installation
Replacing the 2006-2007 Terraza Transmission Control Module is a job most DIYers can handle in under 30 minutes with basic tools. On the Terraza, it’s conveniently located.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On your 2006-2007 Terraza, the TCM is found mounted to the driver’s side (LH) strut tower in the engine bay.
- Disconnect and Remove: Carefully unplug the electrical connectors. Be gentle with the locking tabs. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses.
- 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 fault codes from the vehicle’s memory.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24234274 and is interchangeable with many other GM service numbers. While it is programmed specifically for your Terraza, it is also the correct hardware for a wide range of GM vehicles, ensuring OEM-level function and quality. Confirmed fitment includes:
- ✔ Buick Terraza: 2006-2007 (Located at LH strut tower)
- ✔ Chevrolet Uplander: 2006-2009 (Located at LH strut tower)
- ✔ Pontiac Montana: 2006-2009 (Located at LH strut tower)
- ✔ Saturn Relay: 2006-2007 (Located at LH strut tower)
- ✔ …and many other GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
Frequently Asked Questions
Do I need to have this module programmed by a dealer?
No. This module arrives pre-programmed to your Terraza’s VIN. It is ready for immediate installation right out of the box, saving you time and money.
What is a TCM and what does it do?
The Transmission Control Module (TCM) is the electronic brain of your automatic transmission. It receives data from various sensors and uses it to control shift points, torque converter lockup, and line pressure for smooth and efficient operation.
Is this the same as an ECM or PCM?
No. The TCM specifically controls the transmission. The Engine Control Module (ECM) or Powertrain Control Module (PCM) manages the engine, though they do communicate with each other.
Will this fix a P0700 code?
A P0700 code is a general fault code indicating the TCM has detected a problem. While a failing TCM is a very common cause, you should always diagnose any other codes that are present. In many cases, replacing a faulty 2006-2007 Terraza Transmission Control Module will resolve the issue.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old module without any extra fees or hassle.