P1553

IDLE SPEED CONTROL (ISC) ACTUATOR




The idle speed control actuator is of the double coils type and has two coil, the two coils are driven by separate driver stages in the ECM. Depending on the pulse duty factor the equilibrium of the magnetic forces of the two coils will result in different angles of the motor In parallel to the throttle valve a bypass hose line is arrange, where the idle speed. actuator is inserted in.

CIRCUIT DIAGRAM





HARNESS INSPECTION PROCEDURE





RESISTANCE MEASUREMENT BETWEEN TERMINALS.
1. Disconnect the connector at the idle speed control actuator.




2. Measure the resistance between terminals.

Standard value [at 20°C (68°F)]
Terminal 1 and 2: 10.5 - 14 Ohms
Terminal 2 and 3: 10 - 12.5 Ohms

3. Connect the connector to the idle speed control actuator.


TROUBLESHOOTING PROCEDURES




MALFUNCTION SYMPTOM
Open or short circuit is observed in idle air control system when ignition switch is turned on.






MALFUNCTION SYMPTOM
Mechanical trouble is observed in idle air control system