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 and ETCS-i to suit the operating conditions of the engine in accordance with the signals provided by the sensors.
      Mass Air Flow Meter Sub-assembly Mass Air Flow Meter Silicon Chip Type 1 This sensor has a built-in silicon chip 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.
      Engine Coolant Temperature Sensor Thermistor Type 1 This sensor detects the engine coolant temperature by means of an internal thermistor.
      Crankshaft Position Sensor [No. of Rotor Teeth] Magneto-Resistance Element (MRE) Type [36 - 2] 1 This sensor detects the engine speed and crankshaft angle.
      Camshaft Position Sensor [No. of Rotor Teeth] Magneto-Resistance Element (MRE) Type [3] 1 This sensor detects the camshaft position and is used for cylinder identification.
      VVT Sensor (Intake Camshaft) [No. of Rotor Teeth] Magneto-Resistance Element (MRE) Type [3] 2 (1 each bank)

      • This sensor performs cylinder identification.

      • This sensor is used to detect the intake camshaft position.
      VVT Sensor (Exhaust Camshaft) [No. of Rotor Teeth] Magneto-Resistance Element (MRE) Type [3] 2 (1 each bank)

      • This sensor performs cylinder identification.

      • This sensor is used to detect the exhaust camshaft position.
      Fuel Pressure Sensor Piezoelectric Element Type 1 This sensor detects the fuel pressure.
      Accelerator Pedal Sensor Assembly (Accelerator Pedal Position Sensor) Linear (Non-contact) Type 1 This sensor detects the amount of pedal effort applied to the accelerator pedal.
      Throttle Body with Motor Assembly Throttle Position Sensor Linear (Non-contact) Type 1 This sensor detects the throttle valve opening angle.
      Knock Control Sensor (Bank 1 and Bank 2) Built-in Piezoelectric Type (Non-resonant Type/Flat Type) 4 (2 each bank) This sensor detects engine knocking indirectly through the vibration of the cylinder block caused by engine knocking.
      Air Fuel Ratio Sensor (Bank 1, Sensor 1) (Bank 2, Sensor 1) Heated Type (Planar Type) 2 (1 each bank) As with the heated oxygen sensor, this sensor detects the oxygen concentration in the exhaust gas. However, it detects the oxygen concentration in the exhaust gas linearly.
      Heated Oxygen Sensor (Bank 1, Sensor 2) (Bank 2, Sensor 2) Heated Type (Cup Type) 2 (1 each bank) 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 For Port injection 12-hole Type 8 This fuel injector assembly (for port injection) contains an electro-magnetically operated nozzle to inject fuel into the intake port.
      For Direct injection High Pressure Nozzle Type 8 This injector contains a high-pressure electromagnetically-operated nozzle to inject fuel directly into the cylinder.
      EDU (Injector Driver) Built-in DC/DC Converter 2 The EDU converts the signals from the ECM into high-voltage, high-amperage current in order to drive the direct injection injectors.
      Camshaft Timing Control Motor Assembly EDU-integrated (Brushless Type DC Motor) 2 (1 each bank) The rotational movement of the camshaft timing control motor assembly changes the intake valve timing by operating the camshaft timing gear assembly in accordance with the signals received from the ECM.
      Cam Timing Oil Control Valve Assembly Electro-magnetic Coil Type 2 (1 each bank) The cam timing oil control valve assembly changes the exhaust valve timing by switching the oil passage that acts on the camshaft timing exhaust gear in accordance with the signals received from the ECM.

  2. SYSTEM CONTROL


    1. The engine control system of the 2UR-GSE engine has the following features:

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

      • This is an L-type SFI system. It directly detects the intake air volume with a silicon chip type 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 determines 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.
      Variable Valve Timing-intelligent (Dual VVT-i)

      • Controls the intake and exhaust camshafts to the optimal valve timing in accordance with the engine operating conditions.

      • VVT-iE is used for the intake camshafts. VVT-iE uses electric motors to control the valve timing.

      • VVT-i is used for the exhaust camshafts and uses engine oil pressure to control the valve timing.
      Air Intake Control System The ECM selects between using one, or using both intake air ducts, in order to choose the option that provides the most appropriate balance of noise reduction and airflow for the engine operating conditions.
      Fuel Pump Control For High-pressure Pump Regulates the fuel pressure within a range of 2 to 18 MPa in accordance with driving conditions.
      For Low-pressure Pump

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

      • The fuel pump is stopped when an SRS airbag is deployed in a frontal, side, or rear side collision.
      Air Fuel Ratio Sensor and Heated Oxygen Sensor Heater Control Maintains the temperature of the air fuel ratio sensors or heated oxygen sensors at an appropriate level to increase the ability of each sensor to accurately detect the concentration of oxygen.
      Air Conditioning Cut-off Control By controlling the air compressor with pulley assembly in accordance with the engine operating conditions, drivability is maintained.
      Cooling Fan Control The cooling fan ECU steplessly controls the speed of the fans in accordance with the engine coolant temperature, vehicle speed, engine speed, and air conditioning operating conditions. As a result, cooling performance is improved.
      Cranking Hold Function (Starter Control) Once the engine switch is pushed, this control operates the starter until the engine starts.
      Evaporative Emission Control

      • The ECM controls the purge flow of evaporative emissions (HC) from the canister in accordance with the engine operating conditions.

      • Approximately five hours after the engine switch is turned off, the ECM operates the leak detection pump to detect any fuel vapor leaks between the fuel tank assembly and the canister through changes in the fuel tank pressure.
      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)
      Fail-safe When the ECM detects a malfunction, the ECM stops or controls the engine according to the data stored in memory.
      Diagnosis When the ECM detects a malfunction, the ECM records the malfunction and information that relates to the fault.

  3. FAIL-SAFE


    1. When a malfunction of any of the sensors is detected, there is a possibility of an engine or other malfunction occurring if the ECM were to continue normal control. To prevent such a problem, the fail-safe function of the ECM either relies on the data stored in memory to allow the engine control system to continue operating, or stops the engine if a hazard is anticipated. For details, refer to the Repair Manual.

  4. DIAGNOSIS


    1. When the ECM detects a malfunction, the ECM records information related to the malfunction. Furthermore, the Malfunction Indicator Lamp (MIL) in the combination meter assembly illuminates or blinks to inform the driver.

    2. The ECM also stores Diagnostic Trouble Codes (DTCs) for malfunctions it has detected. The DTCs can be accessed by using the Global TechStream (GTS).

    3. For details, refer to the Repair Manual.