The Multipoint Fuel Injection System consists of sensors which detect the engine conditions, the engine-ECU which controls the system based on signals from these sensors, and actuators which operate under the control of the engine-ECU. The engine-ECU carries out activities such as fuel injection control and ignition timing control. In addition, the engine-ECU is equipped with several diagnosis modes which simplify troubleshooting when a problem develops.


The injector drive times and injection timing are controlled so that the optimum air/fuel mixture is supplied to the engine to correspond to the continually-changing engine operation conditions.
A single injector is mounted at the intake port of each cylinder. Fuel is sent under pressure from the fuel tank by the fuel pump, with the pressure being regulated by the fuel pressure regulator. The fuel thus regulated is distributed to each of the injectors.
Fuel injection is normally carried out once for each cylinder for every two rotations of the crankshaft. The firing order is 1-3-4-2. This is called sequential fuel injection. The engine-ECU provides a richer air/fuel mixture by carrying out "open-loop" control when the engine is cold or operating under high load conditions in order to maintain engine performance. In addition, when the engine is warm or operating under normal conditions, the engine-ECU controls the air/fuel mixture by using the oxygen sensor signal to carry out "closed-loop" control in order to obtain the theoretical air/fuel mixture ratio that provides the maximum cleaning performance from the three way catalyst.


The power transistor located in the ignition primary circuit turns ON and OFF to control the primary current flow to the ignition coil. This controls the ignition timing in order to provide the optimum ignition timing with respect to the engine operating conditions. The ignition timing is determined by the engine-ECU from the engine speed, intake air volume, engine coolant temperature and atmospheric pressure.



  1. Fuel Pump Control
    Turns the fuel pump relay ON so that current is supplied to the fuel pump while the engine is cranking or running.
  2. Oil Feeder Control Valve Control
    The engine-ECU carries out the duty control of the oil feeder control valve according to the operation condition. This varies the phase angle of the camshaft to optimize the valve timing.
  3. Purge Control Solenoid Valve Control
    [Refer to , GROUP 17 - Emission Control <PHEV> - Evaporative Emission Control System - General Information (Evaporative Emission Control System)].
  4. Exhaust Gas Recirculation Valve Control
    [Refer to , GROUP 17 - Emission Control <PHEV> - Exhaust Gas Recirculation (EGR) Valve - General Information (Exhaust Gas Recirculation System)].


Throttle body
Throttle bore mm
Throttle position sensor
Hall element type
Throttle valve control servo
DC motor type, having brushes
Identification No.
Air flow sensor
Heat sensitizing type
Barometric pressure sensor
Semiconductor type
Intake air temperature sensor
Thermistor type
Engine coolant temperature sensor
Thermistor type
Oxygen sensor
Zirconia type
Camshaft position sensor
Magneto resistance element type
Crank angle sensor
Magneto resistance element type
Detonation sensor
Piezoelectric type
Manifold absolute pressure sensor
Semiconductor type
Engine control relay
Contact switch type
Fuel pump relay
Contact switch type
Injector type and number
Electromagnetic type, 4
Injector identification mark
Throttle valve control servo relay
Contact switch type
Oil feeder control valve
Duty cycle type solenoid valve
Exhaust gas recirculation valve
Stepper motor
Purge control solenoid valve
Duty cycle type solenoid valve
Fuel pressure regulator
Regulator pressure kPa