Restore Peak Transmission Performance in Your GM Vehicle
Is your Buick Rainier, Chevrolet Silverado, or GMC Yukon suffering from erratic shifting, delayed gear engagement, or a persistent check engine light? These are classic signs of a failing Transmission Control Module (TCM). The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every shift with precision. When it fails, it can lead to poor performance, decreased fuel economy, and potentially catastrophic transmission damage. This VIN-programmed GM T42 TCM, service number 24243901, is the definitive solution to restore your vehicle’s factory-smooth operation.
From the Diagnostic Bay
We had a 2007 Chevy Tahoe come into the shop stuck in ‘limp mode’—it wouldn’t shift out of third gear. The owner had already replaced two shift solenoids based on the trouble codes, but the problem persisted. A quick scan showed a P0700 code, which is a general transmission fault request. Digging deeper, we found intermittent communication loss with the TCM. Instead of throwing more parts at it, we replaced the original module with a pre-programmed T42 TCM. After a 20-minute installation and clearing the codes, the Tahoe was shifting perfectly. It’s a reminder that sometimes the root cause is the controller, not the components it’s controlling.
Symptoms of a Failing T42 TCM
- ✔ Harsh, erratic, or delayed gear shifts that disrupt your drive.
- ✔ Vehicle becomes stuck in a single gear (often called ‘limp mode’ or ‘fail-safe mode’).
- ✔ Illumination of the Check Engine Light or Transmission Warning Light on your dashboard.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, P0753, P0758, or other solenoid-related faults.
- ✔ A complete inability to upshift or downshift, leading to poor acceleration and high RPMs.
- ✔ Noticeable decrease in fuel efficiency as the transmission operates incorrectly.
- ✔ Intermittent electrical issues or a total loss of communication with the module.
Why Choose Our Programmed GM T42 TCM?
This isn’t just a replacement part; it’s a comprehensive, ready-to-install solution. The critical difference is our expert VIN programming service. Before shipping, we load your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM software updates directly onto the module. This ensures that the TCM is perfectly calibrated for your vehicle’s engine, transmission (4L60E, 4L65E, 4L70E), and tire size right out of the box. You get optimal shift points, correct torque converter lockup, and seamless communication with other vehicle systems, all without a costly trip to the dealership for programming.
Key Features and Benefits
- Plug-and-Play Installation: Because the module is pre-programmed to your VIN, installation is a straightforward mechanical swap. No special tools or dealer software required.
- Restored Drivability: Eliminates harsh shifting and gear hunting, providing a smooth and predictable driving experience.
- Enhanced Reliability: Built to meet or exceed OEM specifications, this module is designed for long-lasting durability, ensuring you won’t have to deal with the same problem again.
- Broad Compatibility: This T42 module is a direct replacement for a wide range of service numbers, including 24252114, 24234503, 24230461, 24234274, 24239224, 24243901, and more.
- No Core Charge: Keep your old part. We don’t require a core return, saving you the time, money, and hassle of shipping your old module back.
Installation and Fitment
Installation is simple for a DIY mechanic or any professional technician. The TCM is typically located in the engine compartment. Common locations across models like the GMC Sierra, Buick LaCrosse, or Saturn Vue include next to the battery, on the LH strut tower, or under the air cleaner box. The process involves disconnecting the battery, unplugging the electrical connectors from the old module, unbolting it, and installing the new one in its place. Once the new module is connected and the battery is reconnected, the vehicle is ready to go. We recommend using a basic scan tool to clear any stored DTCs after installation is complete.
Frequently Asked Questions
How does the VIN programming service work?
During checkout, you will provide us with your vehicle’s 17-digit VIN. Our technicians then use official GM equipment to flash the module with the correct software and calibrations specific to your exact vehicle build. This makes the module a true plug-and-play part.
Will this module fix a P0700 diagnostic trouble code?
A P0700 code is a general fault code indicating that the TCM has detected a problem and requested the check engine light. While a faulty TCM is a very common cause, this code can also be triggered by other transmission issues. Replacing a known-bad TCM is the correct step to resolving the P0700 if the module itself is the source of the fault.
Is this part difficult for a home mechanic to install?
For most supported vehicles, the installation is very straightforward. It typically involves removing a few bolts and unplugging electrical connectors. Since our module comes pre-programmed, there is no complex software or computer work required on your end, making it an accessible DIY repair that can be done in under an hour.
What is the warranty on this transmission control module?
This module comes with a one-year warranty, covering any defects in materials or workmanship. We stand behind the quality of our parts to give you peace of mind with your purchase.
Do I need to send my old TCM back to you?
No, there is no core charge or requirement to return your old part. This simplifies the process for you and eliminates any additional shipping costs or core deposit hassles.