Restore Smooth, Reliable Shifting to Your Chevy Express Van
As a technician with over two decades of experience, I know that when a workhorse like a 2006-2014 Chevrolet Express 2500 Van starts having transmission trouble, it’s more than an inconvenience—it’s a threat to your schedule and your business. The culprit is often a failing Transmission Control Module (TCM). This direct-fit T42 TCM, part number YNXS, is the definitive solution. It arrives expertly programmed to your van’s specific VIN, eliminating the need for expensive dealership visits and ensuring a true plug-and-play repair that gets you back on the road fast.
This module is the brain of your automatic transmission, managing everything from gear changes to torque converter lockup. When it fails, you get the frustrating and often unpredictable symptoms that have likely brought you here. By replacing your old unit with this quality-tested module, you’re not just fixing a part; you’re restoring the dependable performance your work van needs to deliver every day.
Case Study: A Tricky Diagnosis
I once had a 2011 Express 2500 from a local plumbing company come into my shop. The driver complained of intermittent, violent downshifts and occasional limp mode, but no consistent check engine light. We checked the fluid, wiring, and solenoids—all seemed fine. The intermittent nature pointed directly to an electronic failure. After swapping in a VIN-programmed T42 TCM, the problem was solved instantly. The owner was back in business the same afternoon, saving hundreds in diagnostic time and potential lost work. This is a classic failure mode for these modules.
Is Your Express Van Showing These Telltale Signs?
- ✔️ Harsh, slamming shifts or delayed gear engagement.
- ✔️ The vehicle is stuck in a single gear (limp mode), often 2nd or 3rd.
- ✔️ Check Engine Light or Transmission Warning Light is on with codes like P0700, P0750, or other solenoid-related DTCs.
- ✔️ Failure to upshift or downshift, leading to poor acceleration and terrible fuel economy.
- ✔️ The transmission seems to slip between gears or feels like it’s hunting for the right gear.
- ✔️ Unexplained electrical issues that seem to be related to the transmission’s behavior.
A Straightforward Guide to Your 2006-2014 Express 2500 TCM Installation
For the Chevy Express and GMC Savana vans, this is one of the easier module replacements you can do. The entire process should take less than 30 minutes with basic hand tools.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electronic repair. This prevents short circuits and helps reset the vehicle’s systems.
- Locate the TCM: On the 2006-2014 Express/Savana vans, the TCM is conveniently located in the engine compartment on the right-hand (passenger) side. You’ll see it mounted near the firewall or inner fender.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs, so be gentle. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, VIN-programmed TCM into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- Final Steps: Reconnect the battery terminal. Start the vehicle and let it idle for a few minutes. If you have a basic OBD2 scan tool, it’s good practice to clear any stored fault codes. Take the van for a test drive to confirm the shifting is smooth and correct.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for a wide range of General Motors vehicles. While this page focuses on the Express Van, it is also compatible with the following models. Please verify your part number (YNXS or an interchange number like 24252114, 24234503, etc.) for a guaranteed fit.
Partial Fitment List:
- Chevrolet Express 1500/2500/3500 Van (2006-2014): Transmission; (RH engine compartment)
- GMC Savana 1500/2500/3500 Van (2006-2014): Transmission; (RH engine compartment)
- Chevrolet Silverado & GMC Sierra (2007-2013): Transmission; (next to battery)
- Chevrolet Tahoe & GMC Yukon (2007-2009): Transmission; (next to battery)
- Chevrolet Impala (2006-2011): Transmission; (lower air cleaner housing)
- Hummer H3 (2008-2010): Transmission; (RH rear engine compartment)
- …and many other GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
Do I need to take my van to the dealer after installation?
No. This module is pre-programmed to your vehicle’s VIN number. This means it is ready for installation right out of the box, with no additional programming or flashing required. It’s a true plug-and-play solution.
What is a TCM and what does it do?
The TCM, or Transmission Control Module, is a computer that controls the functions of your automatic transmission. It takes data from various sensors on the engine and vehicle to determine the perfect time to shift gears, control line pressure, and engage the torque converter clutch for optimal performance and fuel efficiency.
Will this fix a P0700 trouble code?
A P0700 code is a general fault code, meaning the TCM has detected a problem and has requested the main engine computer (ECM) to turn on the check engine light. While a faulty TCM can cause a P0700, it’s often accompanied by more specific codes. This part will resolve the issue if the TCM itself is the source of the fault.
Is a core charge required for this part?
No, there is no core charge. You can keep or dispose of your old module without the hassle of needing to send it back.
Where is the TCM located on my 2012 Express 2500?
On the 2006-2014 Chevrolet Express and GMC Savana vans, the TCM is located in the engine bay on the passenger side (RH side), making it very accessible for replacement.