SFI SYSTEM

FUNCTION OF MAIN COMPONENTS

The main components of the 1ZR-FAE 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.
Crank Position Sensor [Rotor Teeth]		Pick-up Coil Type [36 - 2]	1	Detects the engine speed and the crank angle.
Cam Position Sensor (No. 1 Crank Position Sensor) [Rotor Teeth]		Magnetic Resistance Element (MRE) Type [3]	2	Performs cylinder identification and detects the VVT angle.
Knock Control Sensor		Built-in Piezoelectric Element Type (Flat Type)	1	Detects an occurrence of engine knocking indirectly from the vibration of the cylinder block caused by the occurrence of engine knocking.
Intake Mass Air Flow Meter Sub-assembly		Hot-wire Type	1	Uses a built-in hot-wire to directly detect the intake air mass.
E. F. I. Vacuum Sensor Assembly		Semiconductor Silicon Chip Type	1	Detects the intake manifold pressure. Corrects the fuel injection in accordance with variations in air pressure. Detects the presence of deposits in the intake valve by determining the intake manifold pressure.
Throttle Body Assembly	Throttle Position Sensor	Non-contact Type	1	Detects the throttle valve opening angle.
Oxygen Sensor		Type with Heater (Cup Type)	1	Detects the oxygen concentration in the exhaust emissions by measuring the electromotive force generated in the sensor itself.
Air Fuel Ratio Sensor		Type with Heater (Planar Type)	1
Accelerator Pedal Sensor Assembly		Non-contact Type	1	Detects the amount of pedal effort applied to the accelerator pedal.
Continuously Variable Valve Lift Controller Assembly		Built-in EDU	1	Includes the EDU and controls the motor in response to signals from the ECM in order to regulate the amount of intake valve lift and the intake valve action angle. The built-in motor position sensor detects the motor position. The built-in action angle sensor detects the position of the actuator in order to confirm the action angle.
Fuel Injector Assembly		12-hole Type	4	Is an electromagnetically-operated nozzle which injects fuel in accordance with the signals from the ECM.
E. F. I. Engine Coolant Temperature Sensor		Thermistor Type	1	Detects the water temperature by means of an internal thermistor.
Duty Vacuum Switching Valve		Solenoid Type	1	Controls the actuator for ACIS in accordance with ECM signals.

SYSTEM CONTROL

The engine control system of the 1ZR-FAE engine has the following systems.

System	Outline
Sequential Multiport Fuel Injection (SFI)	An L-type SFI system 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.
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 the amount of accelerator pedal effort, the throttle valve opening control request from the ECM, and the condition of the engine and the vehicle.
VALVEMATIC	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 Valve Timing-intelligent (Dual VVT-i)	Regulates operation of the intake and exhaust camshafts to ensure an optimal valve timing in accordance with the engine operating conditions.
Acoustic Control Induction System (ACIS)	The intake air passages are switched according to the engine speed and throttle valve opening angle to provide high performance in all speed ranges.
Fuel Pump Control	Fuel pump operation is controlled by signals from the fuel pump control ECU assembly1 or ECM2. The fuel pump is stopped when the SRS airbags deploy.
Cooling Fan Control	The ECM steplessly controls the speed of the fan via the cooling fan ECU in accordance with the engine coolant temperature, vehicle speed, engine speed, and air conditioning conditions*3. As a result, good cooling performance has been achieved.
Starter Control (Cranking Hold Function)*4	Once the engine switch is pushed, this control continues to operate the starter until the engine has started.
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 accuracy of detection of 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*3	By turning the compressor with pulley assembly on or off in accordance with the engine operating conditions, driveability is maintained.
Brake Override System	Restricts the driving torque when the brake pedal is depressed while the accelerator pedal is depressed. (For the Activation Conditions and Inspection Method, refer to the repair manual)

*1: EURO V Models
*2: EURO IV Models
*3: Models with air conditioning system
*4: Models with entry and start system

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.
DIAGNOSIS
1. When the ECM detects a malfunction, the ECM records information related to the fault. 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.