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

Relay Location:

The Auto Shut Down (ASD) Relay supplies power to the ignition coil, fuel injector, electric fuel pump, and the oxygen sensor heater element as long as the key is in the START or RUN position and the Single Module Engine Controller (SMEC) is receiving a reference signal from the distributor. If the SMEC receives no distributor reference signal for two seconds or more the SMEC interrupts power to the ignition coil, fuel injectors, electric fuel pump, and the oxygen sensor heater element by removing the ASD relay ground.