Engine Electrical System

Structure and working principle: The step motor is a
micro-motor, which is comprised of steel stators
installed in a circle and a rotor. Each steel stator has a
coil. The rotor is permanent magnet and the center of
the magnet is a nut. All the coils of stators are always
on. If the current direction of any coil is changed, the
rotor will turn by an angle. If all coils of stators change
their currents directions in a proper order, a rotating
magnetic field will be generated and result in the
permanent magnet rotor rotating in designed direction.
Fault diagnosis: The ECU can detect the circuit short
and circuit open in the two coils of the idle step motor.
Upon the occurrence of such malfunction the engine
malfunction alarm light will be lit and the engine will
enter the malfunction operation mode.
Pins:
Pin A is connected to the 29# pin of ECU;
Pin B is connected to the 4# pin of ECU;
Pin C is connected to the 26# pin of ECU;
Pin D is connected to the 21# pin of ECU.
Troubleshooting: Verify that the four circuits between
the step motor and the ECU are short or open. Verify
that the step motor is jammed. Verify that there is
circuit short or circuit open inside the step motor.
※ Ignition coil ZSK-ROV
Function: The ignition coil transforms the low voltage
of the primary winding into the high voltage of the
secondary winding. The spark plug generates the spark
through discharging and ignites the combustion gas
mixed with air and fuel.
Structure and working principle: The ignition coil is
comprised of the primary winding, the secondary
winding, the iron core, the shell and so on. If the
battery voltage applies on the primary winding, the
primary winding is charged. After the ECU cut off the
circuit of the primary winding the charging will be
stopped and the high voltage will be inducted in the
secondary winding.
Fault diagnosis: Because the ECU is not able to
conduct diagnosing for the ignition coil, there is no
diagnostic trouble code for the malfunction of the
ignition coil. Whether the ignition coil functions
properly can be judged only by inspecting the ignition
coil resistance. The igniti
on coil produces quite a lot
External appearance of
The step
motor
of the idle actuator
Circuit of the stepper of the idle
actuator
E-18
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