Fuel interruption control
If the vehicle slows down with the throttle closed, the electrical current to the injectors is interrupted to improve fuel efficiency at engine speeds above 900 rpm (min-1) provided there is no electrical load (under heavy electrical load condition: 1500 rpm (min-1) Fuel cut-off also occurs to protect the engine from overrun if the engine speed exceeds 6200 rpm (min-1), regardless of throttle position. When the vehicle is stationary, the ECM cuts off the fuel supply at engine speeds greater than 6200 rpm (min-1). The fuel lock speed is slower when the engine is cold.
Fuel pump control
When the ignition is turned on, the ECM supplies «mass» to the main relay 2 of the PGM-FI module (FUEL PUMP), which supplies electrical current to the fuel pump for 2 seconds to pressurize the fuel system. With the engine running, the ECM supplies ground to main relay 2 (FUEL PUMP) PGM-FI module and sends current to the fuel pump. When the ignition is on but the engine is not running, the ECM cuts off the «masses» to the main relay 2 of the PGM-FI module (FUEL PUMP), which interrupts the electrical supply to the fuel pump.
Main relays 1 and 2 of the PGM-FI
Main relay 1 is powered by the PGM-FI module whenever the ignition is turned to «ON» (II) to supply battery voltage to the ECM to supply power to the injectors and to supply power to the main relay 2 of the PGM-FI module («FUEL PUMP»). Main relay 2 («FUEL PUMP») The PGM-FI module receives power to supply electrical power to the fuel pump for 2 seconds when the ignition is turned ON (II), as well as when the engine is cranked by the starter or when the engine is running.