Operation CHARM: Car repair manuals for everyone.

Idle Speed/Throttle Actuator - Electronic: Testing and Inspection




IDLE SPEED CONTROL (ISC) ACTUATOR
The idle speed control actuator is the double coils type and has two coils. 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 used where the idle speed actuator is installed.




CIRCUIT DIAGRAM







HARNESS INSPECTION PROCEDURE




ACTUATOR INSPECTION
1. Disconnect the connector at the Idle Speed Control actuator.
2. Measure the resistance between terminals.

Standard value
Terminal 1 and 2 10.5-14 ohm
Terminal 2 and 3 10-12.5 ohm @ 20°C (68°F)

3. Connect the connector at the Idle Speed Control actuator.







TROUBLESHOOTING PROCEDURES

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