Fuel Pump: Operation
- Activates fuel pump during engine cranking and while engine is running.
- When ignition switch is in START position, current flows, by way of the control relay coil, from the ignition switch to ground. As a result, the control relay switch is switched on, and the power for activation of the fuel pump is supplied, by way of the control relay switch, from the battery to the fuel pump. See Fig 1
.
- While the engine is running, the engine control unit switches on the power transistor, after which current flows to the control relay coil, and the power for activation of the fuel pump is supplied to the fuel pump.
- When the control relay switch is turned on, battery voltage is also applied to the engine control unit, and so the engine control unit detects the fact that the power for activation of the fuel pump is being supplied to the fuel pump.
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.