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An injector is an injection nozzle with the electromagnetic valve that injects fuel based
on the injection signal sent by engine-ECU. 1 injector is installed in the cylinder head of
each cylinder and fixed to the delivery pipe. When electricity flows through the solenoid coil,
the needle gets sucked in. The needle gets pulled till the fully open position so that the injection
hole is fully open and the fuel gets injected. The injected fuel is measured using the small
hole of the orifice disc installed on the injector top.
Voltage from the battery gets applied from the injector relay to the injector and up to
the engine-ECU. Engine-ECU turns ON its power transistor and prepares the injector’s
ground circuit. Thus, current flows through the injector while power transistor is ON and the
injector injects fuel.
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A throttle valve control servo is installed in throttle body. The throttle valve control
servo performs the Open/Close of the throttle valve through the reduction gear. Engine-ECU changes current
direction according to the Open/Close direction and also changes current to the motor coil in
order to the control throttle valve control servo.
Throttle valve control servo is composed of a good response, low energy, and small DC
motor with brush and can generate rotation force corresponding to the current applied on the coil.When
there is no current passing through the throttle valve control servo, the throttle valve remains
at a prescribed opening angle. So, even if current stops because of a fault in the system a
minimum level of running remains possible.
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Refer to GROUP 16 - Ignition Coil  .
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Refer to GROUP 17 - Emission Control - Evaporative Emission Control
System .
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The oil feeder control valve is installed on the inlet side of the cylinder head. Receiving
the duty signal from the engine-ECU, the oil feeder control valve moves the spool valve position
and divides the oil pressure from the cylinder block into the advanced chamber and the retarded
chamber of the V.V.T. sprocket as well as continually changes the inlet camshaft phase. The
spring makes spool valve stop at the position where the inlet camshaft is at the most retarded
angle when the engine is stopped. The engine-ECU moves the spool valve position by increasing
and decreasing ON duty ratio of the oil feeder control valve and allows the inlet camshaft to
be at the target phase angle. When the duty ratio increases, the spool valve moves. The sprocket
rotates toward the advanced angle side. When the duty ratio decreases, the sprocket rotates toward
the retarded angle side. When the medium duty ratio, at which the spool valve is at the medium
position, is achieved, all the oil passages are closed. This allows the phase angle to be kept
constant. The engine-ECU changes and controls the duty ratio in accordance with the engine operation
to get the optimum phase angle.
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Engine-ECU uses ON/OFF of alternator G terminal to control alternator output voltage.
When the power transistor in the engine-ECU turns ON, output voltage gets adjusted to about 12.8
V. When alternator output voltage drops to 12.8 V it becomes lower than voltage of the charged
battery and almost no current is output from the alternator. When the power transistor in the
engine-ECU turns OFF, output voltage gets adjusted to about 14.4 V. When alternator output voltage
is about 14.4 V, alternator outputs voltage current to produce electricity. In case electric
load is generated suddenly, engine-ECU controls alternator G terminal’s On-duty to
limit the sudden increase in alternator load due to generation and thus prevents change in idle
speed.
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