Is your 2006-2007 Terraza suffering from frustrating and unpredictable transmission behavior? Issues like harsh shifting, getting stuck in gear, or an illuminated check engine light can point directly to a failing Transmission Control Module (TCM). As the electronic brain of your automatic transmission, a faulty TCM can disrupt your minivan’s performance and reliability. This OEM-quality T42 TCM, corresponding to part number 24238856, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play repair.
A Technician’s Notebook: The Intermittent Shifting Mystery
I once had a 2007 Terraza in my bay that was giving its owner fits. The complaint was intermittent harsh shifting and occasionally getting stuck in 3rd gear (limp mode), but only after driving for 20-30 minutes. Of course, by the time it got to the shop, it would behave perfectly. We checked fluid levels and scanned for codes—P0700 was present, which is just a general fault request from the TCM. After ruling out wiring issues, we focused on the TCM itself. Heat soak was causing an internal failure. We replaced it with a VIN-programmed unit like this one, and the problem was solved permanently. It’s a classic failure mode for these modules, and this part is the first-time fix.
Is Your Terraza Exhibiting These Transmission Problems?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, it’s highly likely your module is the culprit:
- ✔ Hard, jerky, or erratic gear shifts.
- ✔ The vehicle feels stuck in one gear and won’t shift up or down (limp mode).
- ✔ Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are stored, such as P0700, P0750-P0758 (solenoid codes), or other transmission-related faults.
- ✔ Delayed engagement when shifting from Park to Drive or Reverse.
- ✔ A noticeable drop in fuel economy.
Straightforward 30-Minute Installation Guide
You don’t need to be a master mechanic to replace this part. For the 2006-2007 Terraza, the TCM is conveniently located and the process is simple. No core charge means you can keep your old part without any hassle.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On your Terraza, the TCM is found at the left-hand (driver’s side) strut tower in the engine compartment.
- Disconnect and Remove: Carefully unplug the electrical connectors. Use a socket wrench to remove the bolts holding the old module in place.
- Install the New Module: Mount the new VIN-programmed TCM and secure it with the bolts. Reconnect the electrical harnesses, ensuring they click securely into place.
- Final Steps: Reconnect the battery terminal. While our programming resolves most issues, it’s good practice to use a basic OBD2 scan tool to clear any lingering fault codes from the vehicle’s memory.
Verified Fitment For These GM Models
While this listing is for the Terraza, this T42 TCM is compatible with a wide range of General Motors vehicles. Please verify your model and part number. This module is interchangeable with part numbers: 24252114, 24234503, 24230461, 24234274, 24235340, 24235754, 24239224, and more.
Fits Models Including: TERRAZA 06-07 (LH strut tower), UPLANDER 06-09 (LH strut tower), MONTANA 06-09 (LH strut tower), RENDEZVOUS 06-07 (air cleaner box), IMPALA 06-11 (lower air cleaner housing), MONTE CARLO 06-07 (lower air cleaner housing), GRAND PRIX 06-08, COBALT 06-10, G5/G6 06-10, HHR 06-11, and many more GM cars, trucks, and SUVs. Please see the full list for details.
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 ensures it communicates perfectly with your van’s engine computer and other systems right out of the box, eliminating the need for an expensive trip to the dealership for programming.
Will this part fix my transmission for good?
If your symptoms and diagnostic codes point to a faulty TCM, then yes. This module is built to meet or exceed OEM specifications to provide a durable, long-term solution to common electronic transmission failures. It also comes with a one-year warranty for your peace of mind.
Is this a difficult part to install myself?
Not at all. For a DIYer with basic hand tools, this is a very manageable job. The location on the strut tower is accessible, and the plug-and-play nature of the part means there are no complicated steps. Most people can complete the swap in under 30 minutes.
Will this fix a P0700 code?
A P0700 code is a general fault code, meaning the TCM has detected a problem and has asked the main computer to turn on the check engine light. While this module often resolves the root cause that triggers a P0700, you should scan for more specific P-codes (like those for solenoids) to confirm the diagnosis.