GENERAL INFORMATION


The common rail fuel injection system consists of sensors which detect the condition of the diesel engine, an engine electronic control unit (engine-ECU) which controls the system based on signals from these sensors, and actuators which operate according to control commands from the engine-ECU. The engine-ECU carries out activities such as fuel injection control and idle speed control. In addition, the engine-ECU is equipped with several self-diagnosis functions which make troubleshooting easier in the event that a problem develops.

FUEL INJECTION CONTROL



The injector drive time, the injection timing and the fuel pressure are controlled so that the appropriate quantities of fuel are supplied to the engine in response to engine conditions which can change frequently. A single injector is mounted at each cylinder. The supply pump increases the fuel pressure to the pressure which is required for high-pressure injection, and then send the fuel each injector.

IDLE SPEED CONTROL



The idle speed is kept at the optimum speed by controlling the fuel injection quantity in accordance with changes in idling conditions and engine load during idling.
The engine-ECU drives the fuel injector to keep the engine running at the pre-set idle target speed in accordance with the engine coolant temperature and A/C and other electrical load.

SELF-DIAGNOSIS FUNCTION





OTHER CONTROL FUNCTIONS



















9. AS&G system control <Vehicles with AS&G system>
The AS&G-ECU mostly controls the AS&G system [Refer to GROUP 17 - Auto Stop and Go (AS&G) System <M/T> - General Information ]. The engine-ECU makes a judgment about the following and sends a signal to the AS&G-ECU.

  1. The engine coolant temperature is lower than approximately 50°C or is higher than approximately 90°C.
  2. The intake air temperature is higher than approximately 50°C.
  3. When one or more of the following conditions are satisfied, the vehicle is in "auto stop prohibition status" by electrical load.

  • When the battery is determined as being deteriorated.
  • Diagnosis code No. P0622, diagnosis code No. P1608 or diagnosis code No. U1004 is detected.
  • The diagnosis code causing the MIL to illuminate is detected.
  • Approximately 30 seconds have not been taken since the engine started.
  • When the small injection quantity learning is requested.

    1. The engine coolant temperature is lower than approximately 40 °C.
    2. The amount of the vehicle current consumption is more than the specified value.
    3. Diagnosis code No. P1608 is detected.
    4. When the DPF regeneration is requested.


    Items
    Specifications
    Engine-ECU
    Identification No. (Part No.)
    1860B814 <M/T - 2WD>
    1860C224 <M/T - 4WD>
    1860B815 <A/T>
    Sensors
    Air flow sensor
    Heat sensitizing type
    Engine oil pressure switch
    Contact switch type
    Barometric pressure sensor
    Semiconductor type
    Intake air temperature sensor
    Thermistor type
    Engine coolant temperature sensor
    Thermistor type
    Accelerator pedal position sensor
    Hall element type
    Camshaft position sensor
    Magneto resistance element type
    Crank angle sensor
    Magneto resistance element type
    Manifold absolute pressure sensor
    Piezo resistive semiconductor type
    Throttle position sensor
    Hall element type
    Battery temperature sensor
    Thermistor type
    Battery current sensor
    Hall element type
    Fuel temperature sensor
    Thermistor type
    Exhaust differential pressure sensor
    Piezo resistive semiconductor type
    EGR gas temperature sensor
    Thermistor type
    EGR valve position sensor
    Hall element type
    No. 1 exhaust gas temperature sensor
    Thermistor type
    No. 2 exhaust gas temperature sensor
    Thermistor type
    No. 3 exhaust gas temperature sensor
    Thermistor type
    Rail pressure sensor
    Piezo resistive semiconductor type
    Water level switch
    Contact switch type
    Actuators
    Engine control relay
    Contact switch type
    EGR valve
    DC motor type, having brushes
    Suction control valve
    Duty cycle type solenoid valve
    Fuel pump relay
    Contact switch type
    Injector type and number
    Solenoid control type, 4
    Injector identification mark
    G3S4
    Throttle valve control servo
    DC motor type, having brushes
    Variable geometry control solenoid valve
    Linear type solenoid valve
    EGR cooler bypass control solenoid valve
    ON/OFF type solenoid valve
    A/C compressor relay
    Contact switch type
    Starter relay
    Contact switch type

    FUEL INJECTION SYSTEM DIAGRAM