Fig.1 Power Distribution Center (PDC):

The ASD relay is located in the PDC. The inside top of the PDC cover has label showing relay and fuse identification

The Automatic Shutdown (ASD) relay supplies battery voltage to the fuel injectors, electronic ignition coil and the heating elements in the oxygen sensors.

A buss bar in the Power Distribution Center (PDC) supplies voltage to the solenoid side and contact side of the relay The fuse also protects the power circuit for the fuel pump relay and pump. The fuse is located in the PDC.

The 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 (coil dwell). 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.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Main Relay (Computer/Fuel System): Description and Operation

Fig.1 Power Distribution Center (PDC):

Use the Manual With the Right Hardware

When to See a Mechanic

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