Idle Speed/Throttle Actuator - Electronic: Testing and Inspection

SYSTEM INSPECTION

ISC Valve Connector:

1. Disconnect the ISC valve connector when the engine is cold and idling.
2. Note the engine speed and reconnect the connector.
3. Warm up the engine to the normal operating temperature and disconnect the connector again.
4. Check that the engine speed is lower when the connector is disconnected with a warm engine than when disconnected when the engine is cold.
5. Connect the ISC valve connector.

Test Connector Disconnected:

NOTE: Make sure that the test connector is not grounded and that the idle speed is set to specification.

6. Again disconnect the ISC valve connector with the engine at normal operating temperature.
7. Check that the engine speed decreases.
8. Reconnect the ISC valve connector.

BAC VALVE

Bypass Air Control Valve Removal:

1. Remove the BAC valve from the throttle body.

Bypass Air Control Valve:

2. Blow air through the valve from port "A" and check that air comes out of port "B" when the BAC valve is cold.
3. If not correct replace the BAC valve.

Bypass Air Control Valve Installation:

4. To install the BAC valve, thoroughly clean the mating surfaces of the valve and throttle body. Apply sealant to both sides of the gasket and tighten the screws.

ISC VALVE

1. Disconnect the ISC valve connector.

ISC Valve Resistance Test:

2. Connect an ohmmeter to the terminals of the ISC valve.
3. Check the resistance. The resistance at normal operating temperature should be 6.3-9.9 Ohms.
4. If not correct, replace the BAC valve.

IDLE SWITCH

1. Disconnect the idle switch connector.

Testing Idle Switch:

2. Check continuity between the switch and ground. With the throttle valve fully closed there should be continuity (less than 30 Ohms). With the throttle valve opened there should be no continuity.
3. If not as specified, check the condition of the wiring harness of the idle switch. Replace the idle switch and the throttle body as an assembly, if necessary.