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 test motor circuits as follows:

First, system checks for unwanted voltage.
Then, system supplies voltage on one circuit and reads voltage back on other circuit.
After system checks for opens and shorts on motor circuits, it applies voltage to motor and to ground circuit.
If system detects a high voltage return on ground circuit, DTC is set.
ATC control module senses high voltage return on ground circuit when low voltage signal is expected.

When this DTC is set, all shifting and clutch activation will be disabled. SERVICE 4WD light will be on for remainder of current ignition cycle.