42 Auto Shutdown Relay Control Circuit

42 AUTO SHUTDOWN RELAY CONTROL CIRCUIT





The Automatic Shutdown (ASD) relay controls the battery voltage supplied to the fuel Injectors, ignition coils, O2 sensor heaters, Powertrain Control Module (PCM) pin 42, and the generator field winding. It is located in the Power Distribution Center (PDC). The PCM provides a ground path for the ASD relay at pin 18 when the PCM recognizes an engine RPM signal from the crankshaft position sensor.

ENABLING CONDITIONS
- Battery voltage must be at least 10 volts

The Diagnostic Trouble Code (DTC) is stored in memory if the PCM recognizes high voltage at pin 18 when the ASD relay should be energized, or low voltage at pin 18 when the ASD relay should be de-energized.

This malfunction could possibly be caused by problems with any of the following components:

- ASD relay
- ASD relay's electromagnet wiring or related connectors (open or short)
- PCM