Is Your Savana 1500 Shifting Erratically?
If you’re experiencing harsh shifting, delayed gear engagement, or your 2006-2014 GMC Savana 1500 is stuck in ‘limp mode,’ a failing Transmission Control Module (TCM) is the most likely culprit. The TCM is the electronic brain of your automatic transmission, responsible for orchestrating every gear change and ensuring smooth, efficient operation. When it begins to fail, it can cause a cascade of frustrating and potentially damaging issues, from poor fuel economy to a complete inability to shift gears. This OEM-quality T42 TCM, service part number 24234274, is the definitive solution to restore your van’s transmission performance and get you back on the road with confidence.
From the Diagnostic Bay
We had a 2011 Savana 2500 work van come into the shop that the owner described as ‘possessed.’ It would shift perfectly for a few miles, then suddenly slam into gear or refuse to upshift from second. The check engine light was on, and a scan revealed a generic P0700 transmission fault code along with several solenoid circuit errors. After checking the wiring harness and connectors for damage, we identified the internal circuitry of the original TCM as the source of the intermittent faults. Installing a VIN-programmed T42 module like this one resolved all the codes and restored the van’s shifting to factory-new condition. The pre-programming was key—it saved the owner a trip to the dealership and got his van back in service the same day.
Symptoms of a Failing GM T42 TCM
A faulty TCM can manifest in various ways. If you notice any of the following signs, it’s time to inspect your vehicle’s transmission control module. Early diagnosis can prevent further damage to your transmission’s mechanical components.
- ✔ Erratic and Harsh Shifting: Your transmission may slam into gear, hesitate between shifts, or feel unpredictable.
- ✔ Stuck in Gear or Limp Mode: The vehicle may refuse to shift out of a single gear (often 2nd or 3rd) to protect the transmission from further damage.
- ✔ Warning Lights: The Check Engine Light or a dedicated transmission warning light will illuminate on your dashboard.
- ✔ Diagnostic Trouble Codes (DTCs): Common codes associated with a bad TCM include P0700, P0750, P0753, P0758, and other solenoid-specific faults.
- ✔ Delayed Engagement: A noticeable delay when shifting from Park into Drive or Reverse.
- ✔ Poor Fuel Economy: Inefficient shifting and torque converter lock-up issues can lead to a significant drop in gas mileage.
- ✔ No Communication: In severe cases, a scan tool may be unable to communicate with the TCM, indicating a total failure.
The Plug-and-Play Solution: Your 2006-2014 Savana 1500 TCM
This isn’t just a replacement part; it’s a complete, hassle-free solution. The biggest challenge when replacing a modern TCM is the need for expensive and time-consuming programming at a dealership. We eliminate that step entirely. By providing us with your vehicle’s VIN during checkout, we program the module with the latest GM software specific to your Savana 1500. This ensures that the TCM communicates flawlessly with your vehicle’s Engine Control Unit (ECU) and other systems right out of the box. No extra tools, no dealership appointments, just a straightforward installation.
Built to strict OEM specifications, this module directly replaces a wide range of part numbers, including 24252114, 24234503, 24230461, and more. It is engineered to manage all critical transmission functions, from shift point timing to torque converter clutch control, restoring the precise operation your vehicle was designed for. With a one-year warranty and no core charge, you can make this essential repair with total peace of mind.
Installation is Simple
For most GMC Savana and Chevrolet Express vans, the TCM is conveniently located in the engine compartment on the right-hand (passenger) side. The process is simple enough for a DIY mechanic with basic tools.
- Disconnect the Battery: Always disconnect the negative battery terminal before working on any electronic components.
- Locate the TCM: Find the module on the passenger side of the engine bay.
- Disconnect Wiring Harnesses: Carefully unclip the electrical connectors from the old module.
- Remove the Old Module: Unbolt the old TCM from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the wiring harnesses.
- Reconnect the Battery: Reattach the negative battery terminal.
- Clear Codes: While not always necessary, it’s good practice to use a basic OBD2 scan tool to clear any stored transmission codes after installation.
Frequently Asked Questions
Do I need to get this TCM programmed by a dealer?
No. This module comes fully pre-programmed to your vehicle’s specific VIN. It is ready for installation right out of the box, saving you time and the expense of a dealership visit.
Is this compatible with transmissions other than the 4L60E?
Yes, this T42 TCM is compatible with a range of 4-speed GM automatic transmissions, including the 4L60E, 4L65E, 4L70E, and 4L80E found in a wide variety of GM cars, trucks, and SUVs from 2006-2014.
Where is the TCM located on my 2012 Savana 1500?
On the 2006-2014 Savana and Express vans, the Transmission Control Module is typically located in the engine compartment on the right-hand (passenger) side.
Will this fix a P0700 trouble code?
A P0700 code is a general transmission fault request from the TCM to the ECU to turn on the check engine light. While this module often resolves the underlying issue causing the P0700, you should scan for more specific transmission codes (like P07xx) to confirm the diagnosis.
Is there a core charge for my old part?
No, there is no core charge required for this part. You can keep your old module without any hassle or additional cost.