Is Your GM Vehicle’s Transmission Acting Up?
If you’re dealing with unpredictable shifting, a transmission stuck in ‘limp mode,’ or a persistent check engine light on your 2006-2009 GMC Envoy or other compatible GM vehicle, 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 fails, it can mimic the symptoms of a catastrophic mechanical failure, leading to costly misdiagnoses. This OEM-quality T42 TCM, service number 24240400, is the definitive solution to restore your transmission’s performance and reliability.
From the Diagnostic Bay
We recently had a 2008 Chevrolet Silverado 1500 towed in. The owner was convinced his 4L60E transmission was destroyed. It was slamming into gear and wouldn’t shift past second. He had already been quoted over $3,000 for a transmission rebuild at another shop. Our first step was to pull the diagnostic trouble codes (DTCs). We found a P0700 (Transmission Control System Malfunction) and several solenoid circuit codes. While these codes can point to internal issues, an experienced technician knows to check the controller first. We inspected the wiring and found it intact. Upon testing the TCM itself, we discovered an internal short that was causing the erratic signals to the solenoids. Instead of a costly rebuild, the fix was this exact Programmed T42 TCM. After a simple 20-minute installation, the truck was shifting perfectly, and all codes were cleared. The customer drove away saving thousands of dollars and a lot of headaches.
Symptoms of a Failing T42 TCM
A faulty TCM can manifest in various ways, often intermittently at first. If you notice any of the following issues, it’s time to inspect your module. Ignoring these signs can lead to further damage to your transmission’s mechanical components.
- ✔ Harsh & Erratic Shifting: Your vehicle may slam into gear, hesitate between shifts, or shift at the wrong RPMs.
- ✔ Stuck in Gear / Limp Mode: The transmission may refuse to shift out of a single gear (often 2nd or 3rd) to prevent further damage.
- ✔ Warning Lights: The Check Engine Light or a specific transmission warning light will illuminate on your dashboard.
- ✔ No Upshift or Downshift: The vehicle may fail to shift into higher gears as you accelerate or fail to downshift when you slow down.
- ✔ Poor Fuel Economy: Inefficient shifting and torque converter lock-up control can cause a noticeable drop in your vehicle’s MPG.
- ✔ False Solenoid Codes: The TCM can report false error codes for shift solenoids (e.g., P0751, P0756), leading to unnecessary and expensive part replacements.
- ✔ Complete Communication Loss: In severe cases, the module may stop communicating with the Engine Control Module (ECM) and other vehicle systems, preventing the vehicle from starting or moving.
The Ultimate Solution: A VIN Programmed T42 TCM
What sets this module apart is our professional VIN programming service. Generic, off-the-shelf modules require a trip to the dealership for expensive and time-consuming programming with a Tech 2 or MDI scan tool. Our process eliminates that step entirely. We use the latest GM software updates to flash the module with your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This ensures that the TCM has the correct shift strategies, pressure settings, and software for your exact make, model, and year. It’s a true plug-and-play solution that restores factory performance right out of the box.
Built to strict OEM standards, this T42 TCM guarantees the durability and reliability you expect from a factory part. It directly replaces a wide range of original part numbers, including 24252114, 24234503, 24230461, and many more, making it the ideal choice for a wide array of GM cars, trucks, and SUVs equipped with 4-speed automatic transmissions like the 4L60E, 4L65E, and 4L70E.
Frequently Asked Questions
What does VIN programming mean for me?
VIN programming means the module arrives at your door fully configured for your specific vehicle. You can install it directly without needing any special tools or a trip to the dealership for software flashing. This saves you time and hundreds of dollars in programming fees.
Is this a difficult part to install myself?
For most DIY mechanics, this is a straightforward installation. The TCM is typically located in the engine bay and is accessible with basic hand tools. The entire process usually takes less than 30 minutes. Just remember to disconnect the battery before you begin.
Do I need to return my old TCM (core charge)?
No, there is absolutely no core charge. You can keep your old part, saving you the hassle and expense of return shipping.
Will this module fix specific error codes like P0700?
Yes. A P0700 code is a general fault code indicating the TCM has detected a problem. This module is designed to resolve the internal electronic faults that cause P0700 and related solenoid or sensor codes, provided the fault lies with the module itself and not the wiring or the transmission’s mechanical parts.
What is the warranty on this TCM?
This transmission control module comes with a one-year warranty, giving you peace of mind and confidence in your repair.
How do I find the TCM on my vehicle?
The location varies by model. Common locations include the LH or RH side of the engine compartment, next to the battery, on the strut tower, or under the air cleaner box. Your vehicle’s service manual can provide the exact location.