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.
Park/neutral switch supplies a 12-volt input to ATC control module when vehicle is in Park. Control module uses this input to confirm vehicle is in Park or Neutral. If vehicle is in Park, control module will not allow a range shift from 2H, 4H or AUTO to 4L range.
This DTC detects a voltage on Light Green wire circuit at ATC control module when control module sees a front or rear drive shaft speed signal, or vehicle speed from VCM or PCM over Class 2 data bus.