GM has issued a service bulletin containing a fix for an issue on the 2024 GMC Sierra AT4X that may cause the vehicle’s Sport drive mode to remain incorrectly latched across key cycles.
The problem is related to a glitch in the Body Control Module (BCM) and can be corrected at a GMC dealership without the need for any parts to be replaced.
The Sport Mode glitch may affect 2024 GMC Sierra AT4X trucks equipped with the 3.0L I6 LZ0 turbodiesel Duramax engine – which is standard on the AT4X and rated at 305 horsepower and 495 pound-feet of torque.
Dealership service personnel can confirm involvement of a specific GMC Sierra AT4X by using the GM Global Warranty Management system. Navigating to the truck’s Investigate Vehicle History screen will show it marked as “Open” there if it is involved in the service bulletin.
The actual fix for the problem consists of reprogramming the Body Control Module with the new software update GM has made available. Again, as noted above, no new components need to be installed on the vehicle. According to the service bulletin, the entire reprogramming process can be completed in less than an hour.
The fix is available free of charge to vehicle owners and is available until the end of the truck’s New Vehicle Limited Warranty period. Dealerships are instructed to apply the fix to affected GMC Sierra 1500 units currently in their inventory as well.
As a reminder, Sport Mode “improves vehicle handling and acceleration on dry pavement” per GM’s description of its function. The mode changes the configuration of the exhaust valve opening and also changes steering sensitivity, transmission shifts, the feel of the brake pedal, and the tuning of the suspension to achieve the desired handling and acceleration characteristics. However, when the vehicle is turned off and restarted, it should revert back to the Normal drive mode.
As usual, owners of affected Sierra AT4X trucks can contact GMC customer service at the toll-free number below, referencing the Service Bulletin number as needed, if they have additional questions:
- GM service bulletin number number: N232422180
- GMC U.S. Customer Service: 1-800-462-8782