FUNCTION OF MAIN COMPONENTS
The main components of the 1WW engine control system are as follows:
| Component | Quantity | Function | |
|---|---|---|---|
| ECM | 1 | The ECM performs overall control of the engine control system to suit the operating conditions of the engine in accordance with the signals from the sensors. | |
| Atmospheric Pressure Sensor (Built into ECM) | 1 | This sensor, which is built into the ECM, uses semiconductors to detect the atmospheric pressure. | |
| Atmospheric Temperature Sensor (Built into ECM) | 1 | This sensor, which is built into the ECM, uses a thermistor to detect the atmospheric temperature. | |
| Intake Mass Air Flow Meter Sub-assembly | Mass Air Flow Meter | 1 | This sensor uses a built-in hot-wire to directly detect the intake air mass. |
| Intake Air Temperature Sensor (Built into Intake Mass Air Flow Meter Sub-assembly) | 1 | This sensor detects the intake air temperature by means of an internal thermistor. | |
| Intake Air Temperature Sensor (for Compressed Intake Air) | 1 | This sensor detects the intake air temperature past the turbocharger and intercooler. | |
| Diesel Throttle Body Assembly | Throttle Control Motor | 1 | This motor regulates the opening of the diesel throttle valve in accordance with the signals from the ECM. |
| Throttle Position Sensor | 1 | This sensor detects the diesel throttle valve opening angle. | |
| Accelerator Pedal Position Sensor | 1 | This sensor detects the amount of pedal effort applied to the accelerator pedal. | |
| Fuel Temperature Sensor | 1 | This sensor detects the fuel temperature in the fuel line before the supply pump assembly by means of an internal thermistor. | |
| Fuel Pressure Sensor | 1 | This sensor uses built-in semiconductors to detect the internal pressure of the common-rail assembly. | |
| Crankshaft Position Sensor | 1 | This sensor detects the engine speed and performs cylinder identification. | |
| Camshaft Position Sensor | 1 | This sensor performs cylinder identification. | |
| Turbo Pressure Sensor Assembly | 1 | This sensor detects the intake manifold pressure. | |
| Engine Coolant Temperature Sensor | 1 | This sensor detects the engine coolant temperature by means of an internal thermistor. | |
| Air Fuel Ratio Sensor | 2 | This sensor detects the oxygen concentration in the exhaust gas. | |
| Nozzle Vane Position Sensor | 1 | This sensor detects the nozzle vane position. | |
| Swirl Control Valve Position Sensor | 1 | This sensor detects the diesel swirl control valve opening angle. | |
| Actuator (for Turbocharger) | 1 | This actuator regulates the opening of the nozzle vane in accordance with the signals from the ECM. | |
| Actuator (for Swirl Control) | 1 | This actuator regulates the opening of the swirl control valve in accordance with the signals from the ECM. | |
| Glow Plug Controller | 1 | The glow plug controller controls the length of time for which the current is applied to the glow plug assemblies in accordance with the signals from the ECM. | |
| Fuel Quantity Control Valve | 1 | The valve position is controlled by the signals from the ECM, and a fuel volume that suits the valve position is drawn into the pumping portion (plunger portion). | |
| Pressure Discharge Valve | 1 | The pressure discharge valve regulates the fuel pressure. | |
| Injector Assembly | 4 | The injector injects the fuel to the combustion chamber in accordance with the signals from the ECM. | |
| Fuel Pump Assembly | 1 | The fuel pump assembly feeds fuel to the supply pump assembly. | |
| Glow Plug Assembly | 4 | The glow plug assembly heats the combustion chamber | |
SYSTEM COTROL
The engine control system of the 1WW engine has the following systems:
| System | Outline |
|---|---|
| Fuel Injection Control | Based on the signals received from the sensors, the ECM determines the fuel injection volume and fuel injection timing in accordance with the engine operating conditions. |
| Fuel Pressure Control | Based on the signals received from the fuel pressure sensor, the ECM controls fuel pressure using the fuel quantity control valve and pressure discharge valve in accordance with the engine operating conditions. For details of the fuel quantity control valve operation, see the 1WW Fuel section. |
| Fuel Pump Control | Fuel pump operation is controlled by signals from the ECM in order to feed fuel to the supply pump. |
| Glow Plug Control |
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| Diesel Throttle Control |
|
| Fuel Heater Control*1 | Based on the signals received from the sensors, the ECM controls the fuel heater. |
| Fuel Heater Control*2 | Based on the signals received from the sensors, the ECM controls the fuel heater via the fuel heater relay. |
| Swirl Control | Based on the signals received from the sensors, the ECM controls the actuator (for swirl control), in order to open and close the valve. |
| Turbocharger Control | Based on the signals received from the sensors, the ECM controls the actuator in accordance with the engine operating conditions. |
| Cooling Fan Control | Cooling fan operation is controlled by signals from the ECM based on the engine coolant temperature, air conditioning condition*4, engine speed and vehicle speed. |
| Starter Control*3 | After the engine switch is pushed, continuously operates the starter until the engine is started. |
| Air Conditioning Cut-off Control*4 | This control turns the air conditioning compressor on or off in accordance with the engine operating conditions to maintain driveability. |
| Engine Immobiliser | Prohibits fuel injection if an attempt is made to start the engine with an invalid key. |
| Oil Maintenance Management System |
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| Brake Override System | The driving torque is restricted when both the accelerator and brake pedals are depressed. (For the activation conditions and inspection method, refer to the Repair Manual.) |
| Diagnosis | When the ECM detects a malfunction, the ECM diagnoses and memorizes the failed section. |
| Fail-safe | When the ECM detects a malfunction, the ECM stops or controls the engine in accordance with the data already stored in the memory. |
*1: Models without fuel heater relay
*2: Models with fuel heater relay
*3: Models with smart entry and start system
*4: Models with air conditioning system