Prizm L4-108 1.8L DOHC VIN 8 MFI (1998)
Fuel Pump Relay: Description and Operation
Circuit Opening Relay
The circuit opening relay (1) provides power to the electric fuel pump. The circuit opening relay is controlled by the powertrain control module (PCM).
The PCM provides an electrical ground for the coil of the circuit opening relay which causes the contacts in the relay to close. When the ignition switch
is turned to the START position, the circuit opening relay will be energized to allow the fuel pump to operate and pressurize the system. The fuel pump
will continue to operate if the PCM receives an ignition signal when the engine is started. The fuel pump operates as long as the circuit opening relay is
energized by the PCM. When the circuit opening relay is de-energized, the fuel pump will stop operating.
The circuit opening relay is located in the relay box on the LH side of the engine compartment near the battery.
