Restore Peak Transmission Performance in Your GM Vehicle
Is your 2006-2014 Chevrolet Express 3500 or other GM vehicle suffering from erratic shifting, getting stuck in gear, or displaying transmission-related warning lights? 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 torque converter lockup, and monitoring system health. When it fails, it can lead to poor performance, decreased fuel economy, and potentially catastrophic transmission damage. This OEM-quality T42 TCM, part number 24243921, is the definitive solution to restore your transmission’s smooth and reliable operation.
From the Diagnostic Bay
We had a 2011 Express 3500 work van come into the shop that was a real head-scratcher. The driver reported it would randomly slam into gear, and sometimes it felt like it was starting in 3rd gear from a stop. The check engine light was on with a generic P0700 code, but the specific solenoid codes were intermittent. After checking the wiring harness and fluid, we suspected the TCM. Instead of a costly trip to the dealer for a new module and programming, we installed one of our VIN-programmed T42 units. The installation on the RH side of the engine bay took less than 20 minutes. After a quick battery disconnect to clear the adaptive memory, the van shifted perfectly. The customer was back on the road the same day, saving significant downtime and money.
Why Choose Our Pre-Programmed Express 3500 TCM?
The biggest hurdle in replacing a modern vehicle module is the programming. Our service eliminates this step entirely. We pre-program each T42 TCM to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This process ensures that the module arrives with the latest GM software updates and is perfectly calibrated for your vehicle’s specific transmission (4L60E, 4L65E, 4L70E, or 4L80E) and powertrain configuration. The result is a true plug-and-play installation that requires no expensive scan tools or dealership visits, getting your vehicle back to factory-spec performance right out of the box.
Symptoms of a Failing GM T42 TCM
- ✔ Harsh, delayed, or unpredictable gear shifts.
- ✔ Vehicle enters ‘limp mode,’ often stuck in 2nd or 3rd gear.
- ✔ The check engine light or transmission warning light is illuminated.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700, P0750, or other solenoid-related faults are present.
- ✔ Failure to upshift or downshift, resulting in poor acceleration.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Intermittent or complete loss of communication with the TCM.
Effortless Installation & Wide Compatibility
This module is designed for a straightforward installation. On most Express and Savana vans, the TCM is located in the engine compartment on the right-hand (passenger) side, making it easily accessible. For other compatible models like the Silverado, Tahoe, or Impala, locations may vary slightly (e.g., next to the battery, under the air cleaner box), but the process remains simple. Just disconnect the battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. Reconnect everything, and you’re done. No core charge means you can keep your old part without any hassle.
This unit is a direct replacement for a wide range of GM vehicles and interchanges with numerous part numbers, including 24252114, 24234503, 24230461, 24234274, 24239224, 24256960, and more, ensuring a perfect fit for your repair needs.
Frequently Asked Questions
What does a T42 Transmission Control Module do?
The T42 TCM is a computer that controls all electronic functions of your 4-speed automatic transmission. It receives data from various sensors (like vehicle speed, engine RPM, and throttle position) to determine the optimal time to shift gears, control line pressure, and engage the torque converter clutch for maximum efficiency and smoothness.
Is this module really plug-and-play?
Yes. By providing your vehicle’s VIN during checkout, we program the module with the correct software and calibrations for your specific vehicle. This eliminates the need for any additional programming or setup at a dealership, making it ready for installation as soon as you receive it.
Where is the TCM located on a 2006-2014 Express 3500?
On the Chevrolet Express and GMC Savana vans from this era, the Transmission Control Module is typically found in the engine compartment, mounted on the right-hand (passenger) side. Always confirm the location on your specific vehicle before beginning the replacement.
Will this fix transmission error codes like P0700?
A P0700 code is a general fault code indicating the TCM has detected a problem and has requested the check engine light be turned on. This module will often resolve the root cause of the P0700 and other related codes (like solenoid faults), but you should always diagnose the specific codes to ensure the TCM is the source of the issue. After installation, it’s recommended to clear any stored codes with a basic scan tool.
Do I need to return my old part?
No, there is no core charge for this part. You can keep or dispose of your old module without needing to return it to us, simplifying the repair process for you.