Is Your 2007-2008 Avalanche Shifting Erratically?
If you’re dealing with a transmission that seems to have a mind of its own—slamming into gear, refusing to shift, or causing a check engine light to pop on—you’re not alone. As a mechanic with over two decades of experience, I’ve seen countless GM trucks, especially the 2007-2008 Avalanche 1500, come into the shop with these exact issues. The culprit is almost always a failing Transmission Control Module (TCM). This small electronic unit is the brain of your automatic transmission, and when it starts to go, it can make your powerful truck feel unreliable and unsafe.
From the Diagnostic Bay
I remember a customer with a 2007 Avalanche who was about to give up. His truck would randomly get stuck in 3rd gear (limp mode), but only on hot days after a long drive. He’d already replaced a couple of solenoids with no luck. After hooking up my scan tool, I noticed communication with the TCM was intermittent. We swapped in a VIN-programmed T42 module, and the problem vanished instantly. The original module’s internal circuits were failing under heat—a classic failure mode I’ve diagnosed on hundreds of these GM vehicles. This replacement part is the definitive fix for those frustrating, intermittent electrical gremlins.
Is Your Avalanche Exhibiting These Transmission Problems?
A failing TCM will give you clear warning signs. If you’re experiencing any of the following, it’s time to consider a replacement. Ignoring these symptoms can lead to more significant transmission damage down the line.
- ✔ Harsh, banging shifts or delayed gear engagement.
- ✔ The vehicle is stuck in one gear, often called “limp mode.”
- ✔ Check Engine Light is on with transmission-related Diagnostic Trouble Codes (DTCs) like P0700, P0750, P0753, P0758, or other solenoid-specific codes.
- ✔ Inability to upshift or downshift properly, leading to poor acceleration.
- ✔ A noticeable drop in fuel economy as the transmission isn’t operating efficiently.
- ✔ The transmission temperature warning light may illuminate.
The Direct-Fit Solution: A Pre-Programmed 2007-2008 Avalanche TCM
Don’t waste time and money at the dealership. This T42 Transmission Control Module arrives at your door completely programmed to your truck’s specific Vehicle Identification Number (VIN). This means you can skip the expensive programming fees and long wait times. We load the latest GM software, ensuring the module communicates flawlessly with your vehicle’s engine computer and other systems right out of the box. It’s built to meet or exceed original equipment standards for a long-lasting, reliable repair.
A Straightforward Guide to Installation
For the 2007-2008 Avalanche 1500, this is a job most DIYers can handle in their driveway in under 30 minutes with basic tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts and help reset the system.
- Locate the TCM: On your Avalanche, the TCM is conveniently located in the engine bay, right next to the battery. You can’t miss it.
- Disconnect and Remove: Carefully unclip the electrical connectors. Be gentle with the locking tabs. Then, unbolt the module from its mounting bracket. A small socket set is all you’ll need.
- Install the New Module: Bolt the new, pre-programmed TCM into place and securely reconnect the electrical harnesses. You’ll hear a click as they lock in.
- Reconnect and Verify: Reconnect the battery terminal. Start the engine and check for any warning lights. It’s a good practice to use a basic OBD2 scanner to clear any stored fault codes to ensure a clean slate.
Verified Vehicle Compatibility
This module is a direct replacement for part number 24241806 and other service numbers. While it is guaranteed to fit the specified models below, please verify your part number or contact us with your VIN to ensure perfect fitment.
- ✔ CHEVROLET AVALANCHE 1500: 2007-2008 (Located next to the battery)
- ✔ CHEVROLET SILVERADO 1500: 2007-2013 (Located next to the battery)
- ✔ CHEVROLET TAHOE: 2007-2009 (Located next to the battery)
- ✔ GMC SIERRA 1500: 2007-2013 (Located next to the battery)
- ✔ GMC YUKON / YUKON XL 1500: 2007-2009 (Located next to the battery)
- ✔ Also fits a wide range of other GM cars, trucks, and SUVs from 2006-2014.
Frequently Asked Questions
Do I need to have a dealership program this module?
Absolutely not. We program the module to your vehicle’s VIN before shipping. It arrives ready for plug-and-play installation, saving you hundreds in dealership fees.
Where is the TCM located on my 2008 Avalanche?
You’ll find the Transmission Control Module in the engine compartment, mounted on a bracket right next to the battery.
Will this fix a P0700 trouble code?
In many cases, yes. A P0700 code means the TCM has detected a fault and has requested the check engine light. Replacing a faulty TCM often resolves the root cause of this code and related transmission codes.
What tools are required for this installation?
You only need basic hand tools, typically a 10mm socket or wrench to disconnect the battery and unbolt the module from its bracket.
Is there a core charge for my old part?
No, there is no core charge. You can keep your old module or recycle it without the hassle of sending it back.
My old module has a different number on it. Will this still work?
This part, 24241806, is an interchangeable replacement for many GM service numbers, including 24252114, 24234503, and others. As long as your vehicle is on the compatibility list, this module will function correctly.