Auto Shutdown Relay

The Automatic Shutdown (ASD) relay is located in Power Distribution Center (PDC). See Figure . PDC is located in engine compartment. See Figure . The ASD relay supplies battery voltage to the fuel injectors, ignition coil, generator field winding, EGR solenoid (if equipped) and the heating elements in the oxygen sensors. The Powertrain Control Module (PCM) controls the ASD relay by switching the ground path for the solenoid side of the relay on and off. The PCM turns the ground path off when the ignition switch is in the OFF position. When the ignition switch is in ON or START, the PCM monitors the crankshaft and camshaft position sensor signals to determine engine speed and ignition timing. If the PCM does not receive crankshaft and camshaft position sensor signals when the ignition switch is in the RUN position, it will de-energize the ASD relay.