Restore Full Control of Your 4WD System
If you’re staring at that frustrating “Service 4WD” light on your 2007-2010 Sierra Denali, you’re not alone. As a technician with over two decades of experience, I’ve seen countless GM trucks roll into the bay with an unresponsive four-wheel drive system. The culprit is often a failed Transfer Case Control Module (TCCM). This isn’t just an inconvenience; it’s a reliability issue, especially when you need that 4×4 capability in bad weather or on a tough job site. This module, part number 24241970, is the definitive solution to get your truck’s drivetrain communicating correctly again.
From the Diagnostic Bay: The Intermittent 4WD Ghost
A customer brought in his ’09 Sierra Denali, frustrated because his 4WD would sometimes refuse to engage, and other times get stuck in 4-HI. The selector switch lights would flash but never settle. He’d already replaced the switch on the dash and the transfer case encoder motor, but the problem persisted. After connecting my scan tool, I found communication fault codes (U0102 – Lost Communication with TCCM) that would come and go. In my shop, I’ve diagnosed hundreds of these failures. The root cause is often internal circuit board degradation within the original TCCM, leading to these intermittent “ghost” issues. A simple voltage check at the module confirmed it was receiving power, pointing directly to an internal failure. Replacing the TCCM with this pre-programmed unit resolved all communication errors and restored his 4WD functionality instantly. This is the fix that addresses the core problem, not just the symptoms.
Is Your Truck Exhibiting These 4WD Problems?
A failing TCCM can manifest in several ways. If you’re experiencing any of the following, this module is the likely solution your 2007-2010 Sierra Denali TCCM needs:
- ✔ “Service 4WD” or “Service Four Wheel Drive” message on your driver information center (DIC).
- ✔ Inability to switch between 2WD, 4-HI, 4-LO, or Auto modes.
- ✔ 4WD selector switch lights are flashing, but the system won’t engage or disengage.
- ✔ The vehicle is stuck in a single 4WD mode.
- ✔ Diagnostic Trouble Codes (DTCs) stored in the system, such as C0306, C0321, C0327, C0569, or U0102.
- ✔ A noticeable delay or clunking sound when the transfer case attempts to shift.
A Straightforward Guide to TCCM Installation
One of the best features of this module is that it arrives ready to install. Since we program it to your vehicle’s VIN before shipping, you can skip the expensive trip to the dealership. The physical replacement is a job most DIYers can handle in their own garage.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On most of these GM trucks and SUVs, the TCCM is located behind the lower dash panel on the driver’s side, to the left of the steering column. You may need to remove the knee bolster panel for access.
- Disconnect and Remove: Carefully unplug the electrical connectors from the old module. They have locking tabs that need to be depressed. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed TCCM into the same location. Ensure it’s secure.
- Reconnect: Firmly plug the electrical connectors into the new module. You should hear or feel a click as they lock into place.
- Final Steps: Reinstall any dash panels you removed. Reconnect the negative battery terminal. Start the vehicle and test the 4WD selector switch to confirm proper operation.
Verified Fitment For Your GM Truck or SUV
This module is a direct replacement for a wide range of General Motors vehicles. While this listing focuses on the 2007-2010 Sierra Denali TCCM, it is also compatible with the following models and part numbers. Please ensure your vehicle is on this list for guaranteed compatibility. It replaces part numbers: 24261367, 12588096, 24239190, 24240487, 24241143, 24241970, 24242480, 24243084, 24243085, 24249095, and 24252878.
- Avalanche 1500: 2008-2013
- Sierra 1500/2500/3500: 2007 (New Body Style) – 2014
- Sierra Denali: 2007-2010
- Sierra Denali 2500/3500: 2011-2014
- Silverado 1500/2500/3500: 2007 (New Body Style) – 2014
- Suburban 1500/2500: 2008-2014
- Tahoe: 2008-2014
- Yukon & Yukon XL 1500/2500: 2007-2014
Frequently Asked Questions
Do I need to do any programming or flashing myself?
No. This is the biggest benefit we offer. You provide us with your vehicle’s VIN during checkout, and we flash the module with the latest, most stable GM software specifically for your truck. It arrives at your door ready for a plug-and-play installation.
Where is the TCCM located on my 2008 Sierra Denali?
The Transfer Case Control Module is typically mounted to a bracket behind the dashboard, to the left of the steering column. You will need to remove the lower dash trim panel (knee bolster) to access it.
Is this a used part?
This is a high-quality, inspected, and tested component that has been professionally programmed to function as a new unit. We ensure every module meets strict performance standards before it is flashed and shipped, providing a reliable and cost-effective alternative to a new dealer part.
What if my original part number isn’t 24241970?
That’s very common. GM uses many different part numbers for the same component over the years. We’ve included a comprehensive list of compatible part numbers in the description. As long as your vehicle model and year are listed, this module will work, as the programming is the key factor.
Will this fix my “Service 4WD” light?
In the vast majority of cases where the symptoms match those listed (inability to shift, flashing lights, communication codes), a faulty TCCM is the cause, and this part will resolve the issue and turn off the light. However, it’s always best to have the vehicle properly diagnosed, as other parts like the encoder motor or dash switch can sometimes cause similar issues.