Idle Speed Control (ISC) System

SYSTEM OPERATION
1. Start the engine and run it at idle.





2. Disconnect the idle air control valve connector.
3. Verify that the engine speed decreases.





4. Check air valve operation.
Pinch the air hose to the BAC valve as shown and verify that the engine speed decreases.
5. Connect the idle air control valve connector.


BYPASS AIR CONTROL (BAC) VALVE

Air Valve Inspection




1. Disconnect the air hose.
2. Blow through the BAC valve from port A and check the air flow.

Cold engine: Air flows
Warm engine: Air does not flow


Idle Air Control Valve Inspection
1. Disconnect the idle air control valve connector.





2. Connect an ohmmeter to the idle air control valve terminals.
3. Check the resistance.

Resistance: 10.7 - 12.3 Ohms (at 20°C {68°F})