Restore Peak Transmission Performance in Your GM Vehicle
Is your 2006-2014 Chevrolet Express 1500, or another GM vehicle, suffering from erratic shifting, getting stuck in gear, or displaying a 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 shift points, managing fluid pressure, and ensuring smooth, efficient operation. When it fails, it can lead to poor performance, decreased fuel economy, and potential damage to your transmission. This T42 TCM, part number YNXS, is the definitive solution, arriving pre-programmed to your vehicle’s specific VIN for a true plug-and-play installation.
From the Diagnostic Bay
We had a 2008 Sierra come in with what the owner was sure was a completely failed transmission. It was banging into gear and wouldn’t shift past 2nd. The codes were pointing to multiple solenoid failures (P0751, P0756). Instead of jumping straight to a costly transmission rebuild, we checked the TCM connections and data. We found the TCM was intermittently losing communication. Swapping in a VIN-programmed T42 module like this one cleared all the codes and had the truck shifting perfectly in under an hour. It’s often the electronics, not the heavy mechanical parts, that are the root cause.
Symptoms of a Failing T42 TCM
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ Vehicle entering “limp mode,” often stuck in 2nd or 3rd gear.
- ✔ Check Engine Light or Transmission Warning Light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults.
- ✔ Failure to upshift or downshift properly.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ The transmission may feel like it’s slipping between gears.
Why Choose Our Express 1500 TCM?
This isn’t just a replacement part; it’s a complete solution designed for reliability and ease of installation. We eliminate the guesswork and the need for expensive dealership visits. By providing us with your vehicle’s VIN during checkout, we flash the module with the latest GM-certified software specific to your Express 1500. This ensures that all shift strategies and operational parameters are perfectly matched to your vehicle’s factory specifications, restoring the smooth performance you expect.
Key Features & Benefits:
- VIN Programmed for You: Arrives ready to install with no need for a trip to the dealer for programming. It’s a true plug-and-play fix.
- OEM-Standard Quality: Built to meet or exceed original equipment specifications for dependable, long-lasting performance.
- Broad Compatibility: An exact replacement for multiple part numbers including 24252114, 24234503, 24230461, and YNXS, fitting a wide array of GM trucks, vans, and cars with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E.
- No Core Charge: Keep your old part. There are no core fees or hassles with returning the old module.
- One-Year Warranty: Drive with confidence knowing your purchase is protected against defects for a full year.
Installation & Fitment
Installation is straightforward for a DIY mechanic or any professional technician. The TCM is typically located in the engine compartment—often on the RH side in Express and Savana vans, next to the battery in Silverado and Sierra trucks, or near the LH strut tower in cars like the Cobalt and G6. Always disconnect the battery before beginning the replacement. Once the new module is installed, reconnect the battery and use a standard OBD2 scan tool to clear any stored diagnostic codes. This simple process can have your vehicle back on the road in under 30 minutes.
Frequently Asked Questions
Do I need to get this TCM programmed by a dealer?
No. This module is delivered to you pre-programmed to your vehicle’s VIN. Simply provide your VIN at checkout, and the module will arrive ready for immediate installation without any additional programming required.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault code, indicating that the TCM has detected a problem. 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 P0700 and related codes.
Where is the TCM located on my 2009 Express Van?
On most 2006-2014 Express and Savana vans, the Transmission Control Module is located in the engine compartment, mounted on the right-hand (passenger) side.
Is this compatible with a 4L60E transmission?
Yes, this T42 TCM is the correct controller for a wide range of GM vehicles equipped with 4-speed automatic transmissions, including the 4L60E, 4L65E, 4L70E, and 4L80E.
What is the warranty on this part?
This transmission control module comes with a one-year replacement warranty, giving you peace of mind with your purchase.