Restore Smooth Shifting to Your Workhorse Van
As a technician with over two decades of experience, I know that when a work van like your 2006-2014 GMC Savana 1500 is down, your business is down. One of the most common culprits I see for erratic shifting, dashboard warning lights, and vehicles stuck in “limp mode” isn’t a catastrophic transmission failure, but a faulty Transmission Control Module (TCM). This T42 series module, part number YNXS, is the brain of your automatic transmission, and when it fails, it can cause a whole host of frustrating and costly problems. This replacement module is the definitive solution to get your van back on the road, performing reliably day in and day out.
The biggest advantage we offer is that this module arrives at your door fully programmed to your van’s specific Vehicle Identification Number (VIN). This completely eliminates the need for an expensive trip to the dealership for programming. It’s a true plug-and-play solution designed for both professional mechanics who need to get a customer’s vehicle out of the bay quickly and for savvy DIYers who want to save hundreds on repair bills. By controlling everything from shift points to torque converter lockup, a healthy TCM is critical for performance, fuel economy, and the overall longevity of your transmission.
From the Diagnostic Bay: The “Bad Transmission” That Wasn’t
A fleet manager brought in a 2011 Savana 1500 that was shifting so hard between first and second gear it felt like being rear-ended. Another shop had quoted him over $3,000 for a transmission rebuild, assuming the worst. He was ready to scrap the van. I pulled the codes and saw a P0752 (Shift Solenoid ‘A’ Stuck On). While this can be a solenoid issue, my experience with these 4L60E transmissions screamed “check the TCM first.” The electronics in these modules, especially in hard-working vans, are subjected to constant heat and vibration. We swapped in one of our pre-programmed T42 modules, cleared the codes, and the van shifted like it just rolled off the factory floor. The problem wasn’t the heavy-duty hardware; it was the delicate electronics commanding it. That simple swap saved the client thousands and kept a valuable asset in his fleet.
Is Your Savana Van Showing These Telltale Signs?
A failing TCM doesn’t always mean a dead transmission. If you’re experiencing any of the following, this module is very likely the solution you need. Look out for these common symptoms:
- âś” Abrupt, harsh, or jerky gear shifts.
- âś” Delayed engagement when shifting from Park to Drive or Reverse.
- âś” Transmission is stuck in a single gear (often 2nd or 3rd), a condition known as “limp mode.”
- âś” Check Engine Light or Transmission Warning Light is illuminated on your dash.
- âś” Diagnostic Trouble Codes (DTCs) are present, such as the general P0700 or specific solenoid codes like P0750, P0751, P0752, etc.
- âś” The transmission refuses to upshift or downshift correctly.
- âś” A sudden drop in fuel efficiency or signs of the transmission overheating.
A Straightforward Guide to Your Savana TCM Installation
Replacing the Savana 1500 Transmission Module is a job most people with basic tools can complete in under 30 minutes. In the Savana and Express vans, the location is consistent and easy to access.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work. This prevents short circuits and helps reset the vehicle’s electronic systems.
- Locate the Module: On the 2006-2014 Savana/Express vans, the TCM is typically mounted in the engine compartment on the right-hand (passenger) side. Look for a silver box with electrical connectors attached.
- Disconnect and Remove: Carefully unplug the electrical harnesses from the old module. Press the release tabs firmly to avoid breaking them. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed module into place. Securely plug in the electrical connectors until they click, ensuring a solid connection.
- Final Steps: Reconnect the negative battery terminal. While the module is pre-programmed, it’s always a good practice to use a basic OBD2 scan tool to clear any lingering fault codes from the system’s memory. Start the vehicle and test drive to confirm smooth shifting.
Verified Vehicle Compatibility
This T42 TCM is a direct-fit replacement for a wide range of General Motors vehicles equipped with 4-speed automatic transmissions (like the 4L60E, 4L65E, and 4L70E). While this page focuses on the Savana 1500 Transmission Module, it is also compatible with the following models. Please verify the location noted for your specific vehicle:
- GMC Savana 1500/2500/3500 Van (2006-2014): RH engine compartment
- Chevrolet Express 1500/2500/3500 Van (2006-2014): RH engine compartment
- GMC Sierra 1500/2500 Pickup (2007-2013): Next to battery
- Chevrolet Silverado 1500/2500 Pickup (2007-2013): Next to battery
- Chevrolet Tahoe / Suburban 1500 (2007-2009): Next to battery
- GMC Yukon / Yukon XL 1500 (2007-2009): Next to battery
- Cadillac DTS (2006-2011): RH front engine compartment
- Buick Lucerne (2006-2011): LH engine compartment
- Chevrolet Impala (2006-2011): Lower air cleaner housing
- And many more GM models. This part is interchangeable with service numbers 24252114, 24234503, 24230461, YNXS, and others.
Frequently Asked Questions
Do I need to take this module to a dealer for programming?
Absolutely not. We program the module to your vehicle’s VIN before we ship it. This means it’s ready for installation right out of the box, saving you time and the high cost of dealership programming.
Where is the TCM located on my 2008 GMC Savana 1500?
On the 2006-2014 Savana and Express vans, the Transmission Control Module is conveniently located in the engine bay on the right-hand (passenger) side.
Will this part fix a P0700 trouble code?
A P0700 code is a general fault code indicating the TCM has detected a problem. Often, replacing a faulty TCM will resolve the P0700 code along with any other specific transmission codes that were present.
Is there a core charge for my old part?
No, there is no core charge. You are not required to send your old module back to us, which simplifies the repair process for you.
What kind of warranty is included?
This module comes with a one-year warranty, giving you peace of mind and confidence in the quality and reliability of your purchase.