SFI SYSTEM CONTROL ENGINE CONTROL

  1. FUNCTION OF MAIN COMPONENTS

    1. The main components of the 1KR-FE engine control system are as follows.

      Component

      Outline

      Quantity

      Function

      ECM

      32-bit CPU

      1

      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.

      Crank Position Sensor (Rotor Teeth)

      Pick-up Coil Type (36-2)*1

      1

      Detects the engine speed and performs cylinder identification.

      MRE (Magnetic Resistance Element) Type (36 - 2)*2

      Camshaft Position Sensor (Rotor Teeth)

      Hall Type (3)

      2

      Performs cylinder identification.

      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.

      Vacuum Sensor Assembly

      Semiconductor Silicon Chip Type

      1

      Uses built-in semiconductors to detect the intake manifold pressure.

      Intake Air Temperature Sensor

      Thermistor Type

      1

      • Is built into the vacuum sensor assembly.

      • Detects the intake air temperature by means of an internal thermistor.

      Throttle Position Sensor

      Non-contact Type

      1

      Detects the throttle valve opening angle.

      Heated Oxygen Sensor

      Heated Type (Planar Type)

      2

      Detects the oxygen concentration in the exhaust gas by measuring the electromotive force which is generated in the sensor itself.

      Accelerator Pedal Sensor Assembly

      Non-contact Type

      1

      Detects the amount of pedal effort applied to the accelerator pedal.

      Engine Coolant Temperature Sensor

      Thermistor Type

      1

      Detects the water temperature by means of an internal thermistor.

      Fuel Injector Assembly

      8-hole Type

      6

      Is an electromagnetically-operated solenoid with a nozzle which injects fuel in accordance with signals from the ECM.

      *1: Models without stop and start system

      *2: Models with stop and start system

  2. SYSTEM CONTROL

    1. The engine control system of the 1KR-FE engine has the following systems.

      Components

      Function

      Sequential Multiport Fuel Injection (SFI)

      • The D-type SFI system calculates the intake air volume based on the intake manifold pressure signal received from the vacuum sensor assembly and the engine speed.

      • An independent injection system in which fuel is injected once into each cylinder for each two revolution of the crankshaft is used.

      • Fuel injection takes 2 forms: - Synchronous injection: 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: takes place at the time an injection request based on the signals provided by the sensors is detected, regardless of the crankshaft position.

      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 the ignition (IGT) signal to the igniter.

      Electronic Throttle Control System-intelligent (ETCS-i)

      Optimally controls the throttle valve opening in accordance with the accelerator pedal opening angle, the throttle valve opening control request from the ECM and the engine and vehicle operating conditions.

      Dual Variable Valve Timing-intelligent (Dual VVT-i)

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

      Fuel Pump Control

      Fuel pump operation is controlled by signals from the ECM. The fuel pump is stopped when any of the airbags is deployed in a collision.

      Cooling Fan Control

      Radiator cooling fan operation is controlled by signals from the ECM based on the engine coolant temperature sensor signal and the operating condition of the air conditioning*1.

      Early Stage Injection Control*2

      The ECM calculates appropriate injection and ignition at an early stage. The ECM uses these calculated values when the engine is stopped due to stop and start system control.

      Stopping Position Control*2

      While the engine stopping operation is performed, the ECM uses ignition timing and generator load torque to control the crankshaft position at the time when the engine is stopped. The ECM always positions the crankshaft at the optimal position. This shortens the time necessary to start the engine.

      Starter Control (Cranking Hold Function)*3

      After the engine switch is pushed, continuously operates the starter until the engine starts.

      Heated Oxygen Sensor Heater Control

      Maintains the temperature of the heated 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.

      Air Conditioning Cut-off Control*1

      By turning the compressor with pulley assembly on or off in accordance with the engine operating conditions, drivability is maintained.

      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)

      *1: Models with air conditioning system

      *2: Models with stop and start system

      *3: Models with entry and start system

  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 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.