SFI SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


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

      Component Function
      ECM Optimally controls the engine control system to suit the operating conditions of the engine in accordance with the signals provided by the sensors.
      Intake Mass Air Flow Meter Sub-assembly Air Flow Meter This sensor has a built-in hot-wire element to directly detect the intake air mass.
      Intake Air Temperature Sensor Detects the intake air temperature.
      Engine Coolant Temperature Sensor Detects the engine coolant temperature.
      Fuel Pressure Sensor For Low Pressure Detects the fuel pressure in the fuel delivery pipe.
      For High Pressure
      Crank Position Sensor Detects the engine speed and performs the cylinder identification.
      Cam Position Sensor (No. 2 Crank Position Sensor) (Bank 1, Intake) Performs the cylinder identification.
      (Bank 1, Exhaust)
      (Bank 2, Intake)
      (Bank 2, Exhaust)
      Cam Timing Oil Control Solenoid Assembly (Bank 1, Intake) Controls the intake camshaft (camshaft) phase to achieve the optimal valve timing by moving the oil control valve.
      (Bank 1, Exhaust)
      (Bank 2, Intake) Controls the exhaust camshaft (camshaft) phase to achieve the optimal valve timing by moving the oil control valve.
      (Bank 2, Exhaust)
      Air Fuel Ratio Sensor (Bank 1, Sensor 1) Detects the oxygen concentration in the exhaust emissions by measuring the electromotive force which is generated in the sensor itself.
      (Bank 1, Sensor 2)
      (Bank 2, Sensor 1)
      (Bank 2, Sensor 2)
      Knock Control Sensor Detects an occurrence of engine knocking indirectly from the vibration of the cylinder block caused by the occurrence of engine knocking.
      Throttle Position Sensor Detects the throttle valve opening angle.
      Throttle Control Motor Regulates the opening of the throttle valve in accordance with the signals from the ECM.
      Accelerator Pedal Sensor Assembly Detects the amount of pedal effort applied to the accelerator pedal.
      Fuel Injector Assembly (For Direct Injection) This injector contains a high-pressure electromagnetically-operated nozzle used to inject fuel directly into the cylinder.
      Fuel Injector Assembly (For Port Injection) This injector is an electromagnetically-operated nozzle which injects fuel in accordance with signals from the ECM.
      Ignition Coil Assembly Incorporates an igniter and provides a high level of voltage necessary for ignition in accordance with signals from the ECM.
      Spark Plug Sparks a high level of voltage from the ignition coil assembly inside the cylinder.
      Thermostat Sub-assembly Based on signals from the ECM, the thermostat is opened and closed.

  2. SYSTEM CONTROL


    1. The engine control system has the following features:

      System Outline
      Direct Injection 4-stroke Gasoline Engine Superior Version Sequential Multiport Fuel Injection (D-4S SFI) System

      • 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 D-4S SFI system is a fuel injection system which combines direct injection injectors and port injection injectors.

      • Based on signals from each sensor, the ECM controls the injection volume and timing of each type of injector (direct and port injection types) in accordance with the engine speed and engine load in order to optimize combustion conditions.
      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 ignition (IGT) 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.
      Dual Variable Valve Timing-intelligent (Dual VVT-i) Regulates operation of the intake and exhaust camshaft to ensure an optimal valve timing in accordance with the engine condition.
      Fuel Pump Control (for Low Pressure)

      • Based on signals from the ECM, the fuel pump control ECU controls the fuel pump.

      • The fuel pump is stopped when any of the Supplemental Restraint System (SRS) airbags are deployed.

      • Controls the fuel pressure (low pressure) by controlling the fuel pump (for low pressure) speed in accordance with the engine condition.
      Fuel Pump Control (for High Pressure) Regulates the fuel pressure within a range of 2 MPa to 20 MPa in accordance with driving conditions.
      Cooling Fan Control The cooling fan ECU steplessly controls the speed of the fan in accordance with the engine coolant temperature, vehicle speed, engine speed, and air conditioning operating conditions. As a result, the cooling performance is improved.
      Air Fuel Ratio Sensor Heater Control Maintains the temperature of the air fuel ratio sensor at an appropriate level to increase accuracy of detection of the oxygen concentration in the exhaust gas.
      Thermostat Heater Control Higher opening temperature thermostat is adopted to improve fuel economy. When the vehicle is operated in heavy duty conditions, the heater warms the wax thermostat allowing the engine to operate at cooler temperatures.
      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.)
      Drive Start Control

      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 combination meter assembly and driving torque is reduced to limit the acceleration, helping to avoid a collision.

      *: Depending on the situation, the shift position cannot be changed.
      Evaporative Emission Control

      The ECM controls the purge flow of the evaporative emission (HC) from the charcoal canister assembly in accordance with engine conditions.

      For details, see the 8GR-FKS EMISSION CONTROL section.
      Engine Immobiliser Prohibits fuel delivery and ignition if an attempt is made to start the engine with an invalid key.
      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 diagnoses and memorizes the failed section.