Restore Peak Transmission Performance in Your Chevy Avalanche
If you’re dealing with the frustration of a transmission that won’t shift correctly, is stuck in limp mode, or throws a check engine light, you’re not alone. As a technician with over two decades of experience, I’ve seen countless GM trucks, including the 2007-2008 Chevrolet Avalanche, suffer from these exact issues. The culprit is often a failed T42 Transmission Control Module (TCM). This isn’t just an inconvenience; it’s a critical failure that affects your truck’s drivability, fuel economy, and safety. This replacement T42 TCM, part number 24255280, is the definitive solution, arriving pre-programmed specifically for your truck’s VIN for a hassle-free, plug-and-play repair.
Case Study: The Ghost in the Transmission
A customer brought in his ’07 Silverado with classic symptoms: banging into gear and occasionally getting stuck in 3rd. He’d already spent hundreds replacing shift solenoids, but the problem persisted. A quick scan showed a P0700 and intermittent solenoid circuit codes. From experience, I know that when multiple solenoid codes appear randomly, the issue is rarely the solenoids themselves. It’s usually the module commanding them. We installed one of our VIN-programmed T42 TCMs. The total time on the lift was under 20 minutes. After a short test drive, the shifting was buttery smooth, and all codes were gone for good. This is a prime example of how replacing the 2007-2008 Avalanche 1500 TCM can save you from chasing expensive, incorrect repairs.
Is Your Avalanche Exhibiting These Transmission Problems?
A failing TCM can manifest in several ways. If you notice any of the following, it’s a strong indicator that your module needs replacement. Ignoring these signs can lead to more severe transmission damage down the line.
- ✔ Harsh, erratic, or delayed gear shifts that make driving uncomfortable.
- ✔ Vehicle is stuck in “limp mode,” often locked in 2nd or 3rd gear.
- ✔ The Check Engine Light or Transmission Warning Light is on.
- ✔ Diagnostic Trouble Codes (DTCs) are present, especially P0700 (Transmission Control System Malfunction) or various solenoid codes (e.g., P0751, P0756).
- ✔ A sudden drop in fuel efficiency or a transmission overheating warning.
- ✔ Complete loss of communication with the TCM, preventing diagnostics.
Your Straightforward 30-Minute Installation Guide
One of the best features of this module is its simple installation. You don’t need to be a master mechanic to get your truck back on the road. For the 2007-2008 Avalanche 1500, the TCM is conveniently located in the engine bay.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On your Avalanche, the TCM is typically mounted right next to the battery. It’s a silver box with electrical connectors.
- Disconnect and Remove: Carefully unplug the wiring harnesses. They have locking tabs that need to be released. Then, unbolt the old module from its bracket.
- Install the New TCM: Bolt the new, pre-programmed module into place and securely plug in the wiring harnesses. You’ll hear a click as they lock.
- Final Steps: Reconnect the battery terminal. While the module is plug-and-play, it’s best practice to use a basic OBD2 scan tool to clear any stored fault codes from the system.
Verified Vehicle Compatibility
This T42 TCM is a direct replacement for part number 24255280 and is interchangeable with many other GM service numbers. While this page focuses on the 2007-2008 Avalanche 1500 TCM, it also fits a wide range of other GM vehicles. Please verify your model and options below.
- AVALANCHE 1500 07-08 Transmission; (next to battery)
- ALLURE 06-09 Transmission; (lower air cleaner housing)
- AURA 07-09 Transmission; (LH frame rail front)
- CANYON 08-12 Transmission; (RH rear engine compartment)
- COBALT 06-10 Transmission; (LH strut tower)
- COLORADO 08-12 Transmission; (RH rear engine compartment)
- DTS 06-11 Transmission; (RH front engine compartment)
- ENVOY 06-09 Transmission; (LH engine compartment)
- EXPRESS VANS 1500/2500/3500 06-14 Transmission; (RH engine compartment)
- G5 07-10 Transmission; (LH strut tower)
- G6 06-10 Transmission; (LH strut tower)
- GRAND PRIX 06-08 Transmission; (lower air cleaner housing)
- HHR 06-11 Transmission; (LH engine compartment)
- HUMMER H3 08-10 Transmission; (RH rear engine compartment)
- IMPALA 06-11 Transmission; (lower air cleaner housing)
- ION 06-07 Transmission; (behind LH strut tower)
- LACROSSE 06-09 Transmission; (lower air cleaner housing)
- LUCERNE 06-11 Transmission; (LH engine compartment)
- MALIBU 06-10 Transmission; (LH frame rail)
- MONTE CARLO 06-07 Transmission; (lower air cleaner housing)
- MONTANA 06-09 Transmission; (LH strut tower)
- RAINIER 06-07 Transmission
- RENDEZVOUS 06-07 Transmission; (air cleaner box)
- SAAB 9-7X 06-09 Transmission; (LH engine compartment)
- SAVANA VANS 1500/2500/3500 06-14 Transmission; (RH engine compartment)
- SIERRA 1500/2500 PICKUP 07-13 Transmission; (next to battery)
- SILVERADO 1500/2500 PICKUP 07-13 Transmission; (next to battery)
- SSR 05-06 Transmission; (front LH frame)
- SUBURBAN 1500 07-08 Transmission; (next to battery)
- TAHOE 07-09 Transmission; (next to battery)
- TERRAZA 06-07 Transmission; (LH strut tower)
- TRAILBLAZER 06-09 Transmission; (LH engine compartment)
- UPLANDER 06-09 Transmission; (LH strut tower)
- VUE 07-10 Transmission
- YUKON & YUKON XL 1500 07-09 Transmission; (next to battery)
Frequently Asked Questions
Do I need to have this module programmed?
No. The main benefit of our service is that we program the module to your vehicle’s specific VIN before shipping. It arrives ready for installation with no dealer intervention required.
Where is the TCM located on my 2008 Avalanche 1500?
The Transmission Control Module is located in the engine compartment, mounted on a bracket right next to the battery, making it very easy to access.
Will this fix a P0700 diagnostic trouble code?
In many cases, yes. A P0700 code is a general fault code that simply means the TCM has detected a problem and has requested the check engine light to be turned on. Replacing a faulty TCM often resolves the root cause of the P0700 code.
How do I provide my VIN for programming?
You will be prompted to enter your vehicle’s 17-digit VIN during the checkout process. Please double-check it for accuracy to ensure perfect programming.
Is there a core charge for my old part?
No, we do not require a core return. You can keep or dispose of your old module without any extra hassle or charges.
What kind of warranty is included?
This module is backed by our solid one-year warranty, giving you peace of mind and confidence in your repair.