Circuit Description

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.

Transfer case encoder is a switch that converts a shaft position, representing a range or mode position, into electrical signal inputs to ATC control module. Encoder houses 4 hall effect sensors used for channels "A", "B", "C" and "P". These sensors provide a path to ground when a magnet (part of shift rail) passes over them. ATC control module supplies an 8-volt reference and a ground circuit for encoder hall effect sensors to function via Light Green/Black wire circuit and Black/White wire circuit. ATC control module supplies 5-volt signal on all channels. As these channels are pulled to ground, ATC control module can interpret location of transfer case shift position.

This DTC detects an open, short to ground or a short to voltage condition in encoders channel circuits.