FUNCTION OF MAIN COMPONENTS
The main components of the engine control system are as follows:
| Component | Outline | Quantity | Function |
|---|---|---|---|
| ECM | 32-bit CPU | 1 | The ECM effects overall control of the engine control system to suit the operating conditions of the engine in accordance with the signals provided by the sensors. |
| Injector Driver | DC/DC Converter | 1 | The injector driver is used to drive the injector assembly at high speeds. The injector driver has achieved high-speed driving under high fuel pressure conditions through the use of a DC/DC converter that provides a high voltage, quick-charging system. |
| Turbo Pressure Sensor | Semiconductor Silicon Chip Type | 1 | This sensor uses built-in semiconductors to detect the intake manifold pressure. |
| Atmospheric Pressure Sensor | Semiconductor Silicon Chip Type | 1 | This sensor, which is built into the ECM, uses semiconductors to detect the atmospheric pressure. |
| Fuel Pressure Sensor | Semiconductor Strain Gauge Type | 1 | This sensor uses built-in semiconductors to detect the internal pressure of the common-rail assembly. |
| Pressure Discharge Valve | Solenoid Type | 1 | The pressure discharge valve regulates the fuel pressure. |
| Crank Position Sensor | Pick-up Coil Type (Rotor Teeth/36-2) |
1 | This sensor detects the engine speed and performs the cylinder identification. |
| Camshaft Position Sensor (No. 2 Crank Position Sensor) | Pick-up Coil Type (Rotor Teeth/5) |
1 | This sensor performs the cylinder identification. |
| Intake Mass Air Flow Meter Sub-assembly | Hot-wire Type | 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) |
Thermistor Type | 1 | This sensor detects the intake air temperature by means of an internal thermistor. |
| Intake Air Temperature Sensor (Intercooler Outlet) |
Thermistor Type | 1 | This sensor detects the intake air temperature past the intercooler. |
| Engine Coolant Temperature Sensor | Thermistor Type | 1 | This sensor detects the engine coolant temperature by means of an internal thermistor. |
| Fuel Temperature Sensor | Thermistor Type | 1 | This sensor detects the fuel temperature in the supply pump assembly by means of an internal thermistor. |
| Throttle Position Sensor | Non-contact Type | 1 | This sensor detects the diesel throttle valve opening angle. |
| Accelerator Pedal Sensor Assembly | Non-contact Type | 1 | This sensor detects the amount of pedal effort applied to the accelerator pedal. |
| Nozzle Vane Position Sensor | Non-contact Type | 1 | This sensor detects the nozzle vane position. |
| Suction Control Valve (SCV) | Linear Solenoid Valve | 1 | The SCV position is controlled by the signals from the ECM, and a fuel volume that suits the SCV position is drawn into the pumping portion (plunger portion). |
| Injector Assembly | 8-hole, Solenoid Type | 4 | The injector assembly injects the fuel to the combustion chamber in accordance with the ECM signals via the injector driver. |
SYSTEM CONTROL
The engine control system has the following features. The ECM controls these systems:
| System | Outline |
|---|---|
| Fuel Injection Volume Control | Based on the signals received from the sensors, the ECM determines the fuel injection volume in accordance with the engine condition. |
| Fuel Injection Timing Control | Based on the signals received from the sensors, the ECM determines the fuel injection timing in accordance with the engine condition. |
| During Starting Control | To facilitate startability, the ECM optimally controls the injection volume and injection timing during starting. |
| Idle Speed Control | The ECM determines the idle speed in accordance with the engine condition, and controls the fuel injection volume in order to maintain the target idle speed. |
| Fuel Pressure Control | Based on the signals received from the sensors, the ECM controls fuel pressure using the Suction Control Valve (SCV) and pressure discharge valve in accordance with engine operating conditions. |
| Pilot Injection Control | Based on the signals received from the sensors, the ECM determines pilot injection volume/timing and interval (between pilot injection and main injection) in accordance with the engine condition. |
| Glow Plug Control | The ECM controls the length of time for which the current is applied to the glow plug assemblies, in accordance with the engine coolant temperature. |
| Diesel Throttle Control |
|
| Swirl Control | Based on the signals received from the sensors, the ECM controls the vacuum that is directed to the actuator via the VSV, 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 condition. |
| Air Conditioning Cut-off Control | By controlling the air conditioning compressor on or off in accordance with the engine condition, driveability is maintained. |
| Engine Immobiliser | Prohibits fuel delivery and ignition if an attempt is made to start the engine with an invalid key. |
| 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, it diagnoses and memorizes the failed section. |
| Fail-safe | When the ECM detects a malfunction, it stops or controls the engine in accordance with the data already stored in the memory. |
*: Models with engine immobiliser system