SFI SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The main components of the engine control system are as follows:

      Component Outline Quantity Function
      ECM 32-bit CPU 1 The ECM optimally controls the SFI, ESA, ETCS-i and EGR* to suit the operating conditions of the engine in accordance with the signals provided by the sensors.
      Intake Mass Air Flow Meter Sub-assembly Mass Air Flow Meter Hot-wire Type 1 This sensor has a built-in hot-wire to directly detect the intake air mass.
      Intake Air Temperature Sensor Thermistor Type 1 This sensor detects the intake air temperature by means of an internal thermistor (built into the intake mass air flow meter sub-assembly).
      Engine Coolant Temperature Sensor Thermistor Type 1 This sensor detects the engine coolant temperature by means of an internal thermistor.
      Crank Position Sensor [No. of Rotor Teeth] Pick-up Coil Type [36 - 2] 1 This sensor detects the engine speed and performs cylinder identification.
      Camshaft Position Sensor [No. of Rotor Teeth] Magneto Resistance Element 1 This sensor performs cylinder identification and detects the VVT angle.
      Throttle Body with Motor Assembly Throttle Position Sensor Linear (Non-contact) Type 1 This sensor detects the throttle valve opening angle.
      Knock Control Sensor Built-in Piezoelectric Type (Non-resonant Type/Flat Type) 1 This sensor detects an occurrence of engine knocking indirectly from the vibration of the cylinder block.
      Air Fuel Ratio Sensor Heated Type (Planar Type) 1 As with the oxygen sensor, this sensor detects the oxygen concentration in the exhaust gas. However, it detects the oxygen concentration in the exhaust gas linearly.
      Oxygen Sensor Heated Type (Cup Type) 1 This sensor detects the oxygen concentration in the exhaust gas by measuring the electromotive force which is generated in the sensor itself.
      Fuel Injector Assembly 12-hole Type 4 The injector is an electromagnetically operated nozzle which injects fuel in accordance with signals from the ECM.

      • *: Models with EGR system

  2. SYSTEM CONTROL


    1. The engine control system of the 2AR-FXE engine has the following features.

      System Outline
      Sequential Multiport Fuel Injection (SFI)

      • This is an L-type SFI system. It directly detects the intake air mass with a hot-wire type intake mass air flow meter sub-assembly.

      • The fuel injection system is a sequential multiport fuel injection system.

      • Fuel injection takes 2 forms:


        • Synchronous injection, which always takes place with the same timing in accordance with the basic injection duration and an additional correction based on the signals provided by the sensors.

        • Non-synchronous injection, which takes place at the time an injection request based on the signals provided by the sensors is detected, regardless of the crankshaft position.

      • Synchronous injection is further divided into grouped injection during a cold start, and independent injection after the engine is started.
      Electronic Spark Advance (ESA)

      • Ignition timing is determined by the ECM based on signals from various sensors. The ECM corrects ignition timing in response to engine knocking.

      • This system selects the optimal ignition timing in accordance with the signals received from the sensors and sends (IGT) ignition signals to the igniters.
      Electronic Throttle Control System-intelligent (ETCS-i) Optimally controls the opening angle of the throttle valve in accordance with the accelerator pedal input and the engine and vehicle operating conditions.
      Variable Valve Timing-intelligent (VVT-i) Controls the camshaft (intake) to the optimal valve timing in accordance with engine operating conditions.
      Fuel Pump Control

      • Fuel pump operation is controlled by signals from the fuel pump control ECU.

      • The fuel pump is stopped when any of the Supplemental Restraint System (SRS) airbags are deployed.
      Cooling Fan Control Radiator cooling fan operation is controlled by signals from the cooling fan ECU based on the engine coolant temperature sensor signal and the operating condition of the air conditioning.
      Air Fuel Ratio Sensor and Oxygen Sensor Heater Control Maintains the temperature of the air fuel ratio sensor or oxygen sensor at an appropriate level to increase the ability of the sensor to accurately detect the concentration of oxygen.
      Exhaust Gas Recirculation (EGR) Control* Based on the signals received from the sensors, the ECM determines the EGR volume in accordance with engine operating conditions.
      Evaporative Emission Control The ECM controls the purge flow of evaporative emissions (HC) from the canister in accordance with engine operating conditions.
      Oil Maintenance Reminder System The oil maintenance information message is shown on the multi-information display according to the vehicle condition to inform the driver. For details, see the METER / GAUGE SYSTEM section.
      Fail-safe When the ECM detects a malfunction, the ECM stops or controls the engine according to the data already stored in memory.
      Diagnosis When the ECM detects a malfunction, the ECM records the malfunction and related information.

      • *: Models with EGR control system