Conditions For Setting DTC
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1998 GMC Yukon, 1998 GMC Suburban, 1998 GMC Pickup, 1998 GMC Cab & Chassis, and 1998 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
System will set DTC after trying to engage front axle. If engagement is not accomplished, system will not attempt this again during ignition cycle. ATC control module detects front axle output as a high voltage when low voltage is expected.
Under this condition, all shifting for 4WD and AUTO mode will be disabled. SERVICE 4WD light will be on for remainder of current ignition cycle.