Idle Speed Control Solenoid & Wiring Circuit
- With ignition off, disconnect electrical connector from Idle Speed Control (ISC) solenoid. ISC solenoid is located on right side of throttle body and contains a Blue/Black and Light Green/Black wire connector.
- Turn ignition on. Using voltmeter, check for battery voltage at Blue/Black wire of electrical connector. Battery voltage should exist.
- If battery voltage exists, go to next step. If battery voltage does not exist, check for open circuit in Blue/Black wire between ISC solenoid and EFI main relay. EFI main relay is mounted on ECM, located under left side of instrument panel, near kick panel. See Figure .
- Turn ignition off. Connect test light to battery voltage, and probe Light Green/Black wire. Turn ignition on. Test light should come on momentarily.
- If test light comes on momentarily, go to next step. If test light stays on, check for short to ground in Light Green/Black wire between ISC solenoid and ECM. If test light does not come on momentarily, check for open circuit in Light Green/Black wire between ISC solenoid and ECM. ECM is located under left side of instrument panel, near kick panel. If no open circuit exists, replace ECM.
- Turn ignition off. Using ohmmeter, measure resistance between ISC solenoid terminals. Resistance should be 11-14 ohms at 68°F (20°C).
- If resistance is not within specification, replace ISC solenoid. If resistance is within specification, connect battery voltage to Blue/Black wire terminal and ground Light Green/Black wire terminals momentarily. A "click" sound should be heard to indicate solenoid operation. Replace ISC solenoid if a click is not heard. Reinstall electrical connector.
CAUTION:
DO NOT
apply battery voltage to ISC solenoid for more than one second, and allow 10 seconds between voltage applications to prevent solenoid damage.
NOTE:
Idle-up vacuum switching valve also may be referred to as the Idle Speed Control (ISC) solenoid.