Operation CHARM: Car repair manuals for everyone.

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

PURPOSE
The main relay supplies power to the supplementary air valve, air mass meter, fuel injectors and fuel pump relay.

The relay also applies power to the PCME, generating a system reset which causes the microprocessor to perform an initialization routine, condition input circuits for sensor scanning and run the fuel pump to pressurize the system for starting. The fuel pump relay is PCME timed to limit fuel pump operation to approximately 0.5 second prior to cranking.

OPERATION
The relay is energized when the ignition ON relay is energized by turning the ignition switch to position "II."

Component Panel Locations:




Relay Locations And I.D.:





LOCATION
Beneath right A post.