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

PURPOSE
The main relay provides current to the fuel pump relay, idle air valve, fuel injectors, mass air flow sensor, oxygen sensor pre-heating resistor and to other ECU controlled functions or components.

LOCATION
Forward of the right A-pillar, below fascia.

OPERATION
The fuel injection ECU controls the relay ground connection. When ground is supplied, the system relay is activated and currant can flow to all the related components. If the ground connection is interrupted, no current can reach the components.