SFI SYSTEM

FUNCTION OF MAIN COMPONENTS

System Control Table

The main components of the 2ZR-FXE engine control system are as follows.

Components	Outline	Quantity	Function
ECM	32-bit CPU	1	The ECM optimally controls the SFI, ESA, EGR and ETCS-i to suit the operating conditions of the engine in accordance with the signals provided by the sensors.
Intake Mass Air Flow Meter Sub-assembly	Hot-wire Type	1	This sensor has a built-in hot-wire 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.
Crank Position Sensor (Rotor Teeth)	Pick-up Coil Type (36 - 2)	1	This sensor detects the engine speed and the crank angle.
Cam Position Sensor (No. 1 Crank Position Sensor) (Rotor Teeth)	Magneto-Resistance Element (MRE) Type (3)	1	This sensor performs cylinder identification and detects the VVT angle.
Throttle Body Assembly - Throttle Position Sensor	Linear (Non-contact) Type	1	This sensor detects the throttle valve opening angle.
Knock Control Sensor	Built-in Piezoelectric Element Type (Flat Type)	1	This sensor detects engine knocking indirectly through the vibration of the cylinder block caused by the occurrence of engine knocking.
E. F. I. Engine Coolant Temperature Sensor	Thermistor Type	1	This sensor detects the engine coolant temperature by means of an internal thermistor.
Air Fuel Ratio Sensor (Bank 1, Sensor 1)	Planar Type with Heater	1	As with the oxygen sensor, this sensor detects the oxygen concentration in the exhaust emission. However, it detects the oxygen concentration in the exhaust emission linearly.
Oxygen Sensor (Bank 1, Sensor 2)	Cup Type with Heater	1	This sensor detects the oxygen concentration in the exhaust emission by measuring the electromotive force which is generated in the sensor itself.
Fuel Injector Assembly	12-hole Type	4	The fuel injector assembly is an electromagnetically-operated solenoid with a nozzle which injects fuel in accordance with signals from the ECM.

SYSTEM CONTROL

System Control Table

The engine control system of the 2ZR-FXE engine has the following systems. The ECM that controls this system is made by DENSO.

Components	Function
Sequential Multiport Fuel Injection (SFI)	An L-type SFI system is used and the intake air mass is detected with a hot-wire type air flow meter. The fuel injection system is a sequential multiport fuel injection system. 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. Synchronous injection is further divided into grouped injection during a cold start, and independent injection after the engine is started.
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 conditions.
Variable Valve Timing-intelligent (VVT-i)	Controls the camshaft (intake) to an optimal valve timing in accordance with the engine operating conditions.
Cooling Fan Control	Cooling fan operation is controlled by signals from the ECM based on the engine coolant temperature, air conditioning operation conditions, and hybrid system coolant temperature.
Water Pump Control	Engine water pump assembly operation is controlled by signals from the ECM.
Fuel Pump Control	Fuel pump operation is controlled by signals from the ECM. The fuel pump is stopped when any of the SRS airbags deploy.
Air Fuel Ratio Sensor and Oxygen Sensor Heater Control	Maintains the temperature of the air fuel ratio sensor or oxygen sensor at an appropriate level to increase the ability of the sensors to accurately detect the oxygen concentration.
Exhaust Gas Recirculation (EGR) Control (For details, Click here	Based on the signals received from the sensors, the ECM determines the EGR volume in accordance with the engine operating conditions.
Evaporative Emission Control	The ECM controls the purge flow of evaporative emissions (HC) from the canister in accordance with the engine operating conditions. Approximately 5 hours after the power 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.
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 records the malfunction and information that relates to the fault.

FAIL-SAFE

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

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 or blinks to inform the driver.
The ECM will also store the Diagnostic Trouble Codes (DTCs) of the malfunctions. The DTCs can be accessed by using the Global TechStream (GTS).
For details, refer to the Repair Manual.