S10/T10 Blazer 4WD V6-4.3L VIN W (1997)
Transfer Case Actuator: Description and Operation
Motor and Relay Voltage Checks
Whenever the electric-shift motor is turned on or off, the motor and its electrical circuits are tested both in the de-energized and energized condition. If
one or both voltage relays fail to detect the proper voltage after energizing or de-energizing, the shift is aborted by the Transfer Case Control Module
(TCCM) and a DTC of 3 is stored to indicate a faulty TCCM motor circuit.
If one or both relays fail to detect the proper voltage after de-energizing, both relays are turned on by the TCCM (even with the ignition switch
positioned off) to prevent the motor from running. The TCCM then stores a DTC of 3 to indicate a faulty TCCM motor circuit. The all the status lamps
blink three times, stop, and repeat the blinking continuously to alert the driver that the electronic shift system requires immediate repair. The battery will
drain when this condition occurs, regardless of the ignition switch position.
