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.
Front and rear drive shaft speed sensors are a permanent magnet generator, producing AC voltage pulses. AC voltage level and number of pulses increases as speed increases. ATC control module converts pulsating AC voltage to drive shaft RPM which is used for calculations. Control module uses these inputs when vehicle is in 4H, 4L and AUTO ranges only. Drive shaft RPM can be displayed using scan tool. This DTC detects a difference in speed sensor inputs of more than 20 percent.