Function of Equipment

FUNCTION OF EQUIPMENT





Control Unit

Main function
- Fuel injection rate control
- Fuel injection timing control

Supplementary function
- Self-diagnosis function
- "Back up" function





Pre-stroke Actuator/Sensor
The pre-stroke actuator is installed at the front of the injection pump. It consists of the pre-stroke sensor and pre-stroke servo that is actuated by signals from the control unit.
The pre-stroke sensor is inside the pre-stroke actuator. It compares the target position instructed from the pre-stroke control unit with the actual position to detect if the position is correct, and feeds this information back to the control unit.







Engine Speed Sensor
The engine speed sensor is installed to the gear case and detects the engine speed with a magnetic pick-up.
The engine speed sensor detects the potential difference generated when gear teeth traverse the tip of the engine speed sensor and sends the potential difference to the control unit (4 pulses by one rotation of the engine).







Engine Coolant Temperature Sensor
The engine coolant temperature sensor is a variable resistor (thermistor type) in which the resistor changes according to the change in the temperature of the engine cooling water. It reads the engine coolant temperature as the change in the resistance, and inputs an electrical signal to the control unit.
The engine coolant temperature sensor is installed at the water
manifold.







Rack Sensor
The rack sensor is a non-contact displacement meter that acts to send the movement of the control rack of the injection pump to the control unit.
The rack sensor sends out an alternating wave current (sine wave) from the OSC terminal (oscillation terminal) of the control unit. It detects the position of the rack from the MDL (middle) signal generated by the change in the impedance (self-induction) between the two coils, and sends this to the control unit.










Diagnostic Switch
The diagnostic switch is the switch used to carry out troubleshooting of the electronic control system.
The diagnostic switch consists of one pair of male and female terminals. These are normally connected; they are disconnected only when carrying out trouble-shooting.
The diagnostic switch is installed behind the electrical unit board and labeled with a "DIAGNOSIS" tag.







Memory Reset Switch
This switch is used to delete the control unit trouble data from memory. To delete the data, short circuit the connector terminals for about ten seconds.
The memory reset switch is installed behind the electrical unit board and labeled with a "MEMORY" tag.