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 Optimally controls the engine control system to suit the operating conditions of the engine in accordance with the signals provided by the sensors.
      Air Fuel Ratio Sensor (Bank 1, Sensor 1) Heated Type (Planar Type) 1 Detects the oxygen concentration in the exhaust gas by measuring the electromotive force which is generated in the sensor itself.
      Oxygen Sensor (Bank 1, Sensor 2) Heated Type (Cup Type) 1
      Intake Mass Air Flow Meter Sub-assembly Silicon Chip Type 1 Uses a built-in silicon chip to directly detect the intake air volume.
      Intake Air Temperature Sensor Thermistor Type 1 Detects the intake air temperature.
      E.F.I. Engine Coolant Temperature Sensor Thermistor Type 1 Detects the engine coolant temperature.
      Crank Position Sensor [Rotor Teeth] Magneto Resistive Element (MRE) Type [36 - 2] 1 Detects engine speed and performs cylinder identification.
      Cam Position Sensor [Rotor Teeth] Magneto Resistive Element (MRE) Type [3] 2 Performs cylinder identification.
      Throttle Position Sensor Non-contact Type 1 Detects the throttle valve opening angle.
      Accelerator Pedal Sensor Assembly Non-contact Type 1 Detects the amount of pedal effort applied to the accelerator pedal.
      Knock Control Sensor Built-in Piezoelectric Element Type (Flat Type) 1 Detects engine knocking indirectly through the vibration of the cylinder block caused by engine knocking.
      E.F.I. Vacuum Sensor Assembly Semiconductor Silicon Chip Type 1

      • Detects the intake manifold pressure.

      • Corrects the fuel injection volume in accordance with variations in air pressure.

      • Detects the presence of deposits on the intake valves by determining the intake manifold pressure.
      Temperature Sensor Thermistor Type 1 Detects the engine oil temperature.
      Continuously Variable Valve Lift Controller Assembly Built-in EDU 1

      • Includes the EDU and controls the VALVEMATIC mechanism in response to signals from the ECM in order to regulate the amount of intake valve lift and the intake valve action angle.

      • Uses a built-in motor position sensor to detect the VALVEMATIC actuator position.

      • Uses a built-in action angle sensor to detect the position of the VALVEMATIC actuator in order to confirm the action angle.
      Camshaft Timing Oil Control Valve Assembly Solenoid Type 2 Changes the oil passage to the VVT-i controller in response to signals from the ECM.
      Throttle Control Motor DC Motor 1 Regulates the opening of the throttle valve in accordance with the signals from the ECM.
      Fuel Injector Assembly 12-hole Type 4 The fuel injector assembly is an electromagnetically-operated nozzle which injects fuel in accordance with the signals from the ECM.
      Ignition Coil Assembly Type with Igniter 4 Incorporates an igniter and provides high-voltage electricity necessary for ignition in accordance with signals from the ECM.
      Spark Plug Iridium-tipped Type 4 Produces high-voltage sparks from the ignition coil assembly inside the cylinder.

  2. SYSTEM CONTROL


    1. The engine control system has the following features. The ECM controls these systems:

      System Outline
      Sequential Multiport Fuel Injection (SFI)

      • This L-type SFI system detects the intake air volume with a silicon chip type intake mass air flow meter sub-assembly.

      • The fuel injection system is a sequential multiport fuel injection system.
      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.
      Electronic Throttle Control System-intelligent (ETCS-i) Optimally controls the throttle valve opening in accordance with accelerator pedal opening angle effort, the throttle valve opening control request from the ECM and the engine and vehicle operating conditions.
      VALVEMATIC System Effects coordinated control with the dual VVT-i in order to control the amount of intake valve lift, and intake and exhaust valve timing.
      Dual Variable System Valve Timing-intelligent (Dual VVT-i) Controls of the intake and exhaust camshafts to ensure an optimal valve timing in accordance with the operating condition.
      Cooling Fan Control Controls the radiator cooling fan operation in accordance with signals from the ECM based on the engine coolant temperature signal (THW) and the operating condition of the air conditioning system.
      Fuel Pump Control

      • Fuel pump operation is controlled by signals from the ECM.

      • The fuel pump is stopped when any of the Supplemental Restraint System (SRS) airbags are deployed.
      Evaporative Emission Control The ECM controls the purge flow of evaporative emissions (HC) from the charcoal canister in accordance with engine conditions.
      Starter Control (Cranking Hold Function)* After the engine switch is pushed, continuously operates the starter until the engine has started.
      Air Conditioning Cut-off Control By controlling the air conditioning compressor assembly in accordance with the engine operating condition, driveability is maintained.
      Air Fuel Ratio Sensor and Oxygen Sensor Heater Control Maintains the temperature of the air fuel ratio sensor and oxygen sensor at an appropriate level to increase the ability of each sensor to accurately detect the oxygen concentration in the exhaust gas.
      Engine Immobiliser Prohibits fuel delivery and ignition if an attempt is made to start the engine with an invalid key.
      Drive Start Control System If an abnormal shift (R to D/M, D/M to R, N to R, P to D/M, P to R) is detected while accelerating, a warning is displayed in the multi-information display and motive force is reduced to limit the acceleration, helping to avoid a collision.
      Brake Override System When the accelerator and brake pedals are depressed at the same time, the motive force may be restrained. (For the Activation Conditions and Inspection Method, refer to the Repair Manual.)

      *: Models with entry and start system

  3. FAIL-SAFE


    1. When the ECM detects a malfunction, the ECM stops or controls the engine according to the data already stored in the memory. For details, refer to the Repair Manual.

  4. DIAGNOSIS


    1. When the ECM detects a malfunction, the ECM diagnoses and memorizes the failed section. For details, refer to the Repair Manual.