Prowler V6-3.5L VIN G (1999)
Fuel Pump Relay: Description and Operation
AUTOMATIC SHUTDOWN (ASD) AND FUEL PUMP RELAYS
The PCM operates the ASD relay and fuel pump relay through one ground path. The PCM operates them by switching on and off the ground path for
the solenoid side of the relays. Both relays turn on and off at the same time.
The ASD relay connects battery voltage to the fuel injectors and ignition coil. The fuel pump relay connects battery voltage to the fuel pump.
The PCM turns the ground path off when the ignition switch is in the Off position. Both relays are off. When the ignition switch is in the On or Crank
position, the PCM monitors the crankshaft position sensor and camshaft position sensor signals to determine engine speed and ignition timing (coil
dwell). If the PCM does not receive a crankshaft position sensor signal and camshaft position sensor signal when the ignition switch is in the Run
position, it de-energizes both relays. When the relays de-energize, battery voltage is not supplied to the fuel injectors, ignition coil and fuel pump.
Power Distribution Center
The ASD relay and fuel pump relay are located in the Power Distribution Center (PDC) near the battery. A decal on the underside of the PDC cover
shows the locations of each relay and fuse contained in the PDC.
