Air Switching, Coast Air & Decel Spark Advance Systems Testing

ASV & CAV TEST

1. Start and operate engine at idle.
2. Disconnect solenoid valve connector. If the idle speed falls excessively or the engine stalls, the ASV, CAV and solenoid valve are operating properly.
3. If idle speed does not change, check condition of the vacuum passage for clogging and condition of ASV, CAV and solenoid valve.
4. With engine idling, use a voltmeter and check for battery voltage at the solenoid connector. If voltage is present, electrical wiring or engine speed sensor is defective. Replace wiring or engine speed sensor.
5. Increase engine speed to 2500 RPM. Check to ensure voltage is present at solenoid connector. If no voltage, engine speed sensor is defective. Replace engine speed sensor.

DSAS TEST

1. Connect a timing light to the vehicle.
2. Start and operate engine at idle.
3. Disconnect solenoid valve connector while watching the timing marks.
4. If ignition timing advances, the solenoid valve and advance mechanism are operating properly. If not, replace solenoid valve.