Fuel System: 1G-7
High Pressure Fuel Pump Control System Description
ZAJ6111701003
To supply the optimum fuel amount, the ECM controls the fuel pump drive duty cycle, a repeated “ON” / “OFF” signal,
at a specified rate (1 000 times a second).
Based on engine speed and battery voltage, the ECM determines the optimum duty cycle (repeating “ON” time rate
within a cycle) and sends this signal to the fuel pump.
Duty cycle signal for fuel pump (example: 80% duty)
CKP sensor:
Informs ECM of engine speed.
Ignition switch:
Informs ECM of “START” signal.
Cylinder temp. sensor:
Informs ECM of cylinder temperature.
Battery voltage
ECM
Signal FP
Fuel pump
1. Sensor/switch signal input 5. 30 A fuse
2. Fuel pump 6. Battery charge coil
3. ECM main relay 7. Rectifier/Regulator
4. 30 A fuse 8. Ignition switch
“ON” time
1 cycle time
× 100 = duty (%)
0.8 ms
Time
1 ms (1cycle)
OFF
ON