Suzuki DF70A - High Pressure Fuel Pump Control System Description

1G-7 Fuel System:
High Pressure Fuel Pump Control System Description
Z9J0111701003
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
I9J011170006-01
1. Sensor/switch signal input 6. 40 A fuse
2. Fuel pump 7. Battery charge coil
3. ECM main relay 8. Rectifier/Regulator
4. 30 A fuse 9. Ignition switch
5. 15 A fuse
ECM
CPU
FP
BATT
1
5
6
4
8
7
3
9
2
I9J011170007-01
“ON” time
1 cycle time
× 100 = duty (%)
0.8 ms
Time
1 ms (1cycle)
OFF
ON
I9J011170008-01
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