The ASD relay connects battery voltage to the fuel
injector and ignition coil. The fuel pump relay con-
nects battery voltage to the fuel pump and oxygen
sensor heating element.
The PCM turns the ground path off when the igni-
tion switch is in the Off position. Both relays are off.
When the ignition switch is in the On or Crank po-
sition, the PCM monitors the camshaft position sen-
sor and crankshaft position sensor signals. From
these inputs, the PCM determines engine speed and
ignition timing (coil dwell). If the PCM does not re-
ceive a camshaft position sensor signal when the ig-
nition switch is in the Run position, it will de-
energize both relays. When the relays are de-
energized, battery voltage is not supplied to the fuel
injector, ignition coil, fuel pump and oxygen sensor
heating element.
On AC, AG, AJ and AY models, the ASD relay and
fuel pump relay are located in the power distribution
center (Fig. 35, 36, 37, or 38).
On AA and AP models, the ASD relay and fuel
pump relay are mounted on the drivers side fender
well, next to the strut tower (Fig. 39).
Fig. 33 MAP Sensor—Turbo III Engine
Fig. 34 Map Sensor—3.3L and 3.8L Engines
Fig. 35 Power Distribution Center (PDC) (AC Body)
Fig. 36 Relay Identification (AC Body)
Fig. 37 Power Distribution Center (PDC)
(AG and AJ Body)
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IGNITION SYSTEMS
8D - 33