Is Your GM Vehicle Shifting Erratically?
If your Chevrolet Express, Silverado, Tahoe, or other GM vehicle is experiencing harsh shifting, getting stuck in gear, or showing transmission-related warning lights, a failing Transmission Control Module (TCM) is the likely culprit. The TCM is the electronic brain of your automatic transmission, responsible for managing gear changes, torque converter clutch engagement, and fluid pressure. When it fails, it can cause a wide range of drivability problems that can be frustrating and potentially damaging. This T42 TCM, part number 24238856, is the definitive solution to restore your transmission’s original performance and reliability.
From the Diagnostic Bay
We had a 2008 Sierra 1500 in the shop that was throwing a P0752 code (Shift Solenoid A Stuck On) and was stuck in 3rd gear limp mode. The owner had already replaced the solenoid pack inside the transmission pan, but the problem persisted. After a quick scan, we saw erratic data from the TCM. Instead of a costly transmission rebuild, we installed one of these pre-programmed T42 modules. After a 20-minute installation and clearing the codes, the truck was shifting perfectly. The issue wasn’t a mechanical failure in the transmission itself, but a communication breakdown originating from the old, faulty module.
Symptoms of a Failing T42 TCM
- ✔ Harsh, erratic, or delayed gear shifts that disrupt your driving experience.
- ✔ Vehicle entering ‘limp mode,’ often stuck in a single gear (like 2nd or 3rd) to protect the transmission.
- ✔ Check Engine Light or Transmission Warning Light illuminated on the dashboard.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, such as P0700, P0750, or other solenoid-specific codes.
- ✔ Complete failure to upshift or downshift, leading to poor acceleration and performance.
- ✔ A noticeable decrease in fuel economy due to inefficient transmission operation.
- ✔ Intermittent loss of communication with the module, causing unpredictable behavior.
Why Choose Our 2006-2014 Express 1500 TCM?
This isn’t just a replacement part; it’s a complete, ready-to-install solution. The biggest hurdle in replacing a modern vehicle module is the need for expensive dealership programming. We eliminate that step entirely. By providing your vehicle’s VIN during checkout, we program the module with the latest GM software specific to your vehicle. This ensures it communicates flawlessly with the Engine Control Module (ECM) and other vehicle systems right out of the box. This plug-and-play convenience saves you time, money, and the hassle of a trip to the dealer.
Built to meet and exceed original equipment specifications, this module is engineered for durability and long-term performance. It directly replaces a wide range of original part numbers, including 24252114, 24234503, 24230461, and many more, making it the ideal choice for a vast array of GM models from 2006 to 2014. Whether you’re working on a workhorse Savana van, a family Yukon, or a daily driver Impala, this 2006-2014 Express 1500 TCM delivers the reliable performance you need.
Frequently Asked Questions
What does the T42 Transmission Control Module do?
The T42 TCM is the central computer for your automatic transmission. It processes data from various sensors (like vehicle speed, throttle position, and engine RPM) to control shift solenoids, regulate hydraulic pressure, and manage the torque converter lockup, ensuring smooth and efficient gear changes.
Is any additional programming required after installation?
No. This module is delivered pre-programmed to your vehicle’s specific VIN. This means it is ready for immediate installation without the need for a dealership scan tool or costly programming fees. It’s a true plug-and-play solution.
How do I know for sure that my TCM is the problem?
Common signs include erratic shifting, limp mode, and specific transmission-related trouble codes (like P0700). While these symptoms strongly point to a faulty TCM, it’s always best to have a qualified mechanic perform a full diagnostic scan to rule out other potential issues like faulty solenoids or wiring problems.
Where is this module located on my vehicle?
The location varies by model. Common locations include the engine compartment on the RH or LH side, next to the battery, under the air cleaner box, or on the LH strut tower. Your vehicle’s service manual will show the exact location.
Will this part fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem and requested the Check Engine Light be turned on. Replacing a faulty TCM often resolves the underlying issue that caused the P0700 code and related specific codes (e.g., P0750-P0758). After installation, all codes should be cleared.