Circuit Description
WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The transfer case shift control module controls the Transfer Case Lock Solenoid. The lock is energized (locking action released, by grounding the Lock Control Circuit) during gear shifts and in AUTO 4WD mode of operation. When power or ground is removed from the lock solenoid (locking action applied, releasing the ground on the Lock Control Circuit), the Transfer Case Motor is prevented from moving. In this manner the system is capable of providing a 4H and 4L lock-up without the need of additional vehicle power to hold the Transfer Case in these positions.
This DTC detects a shorted lock solenoid coil, or the Lock Control Circuit shorted to 12 V.