Idle Up Control Valve: Testing and Inspection

1. Connect ECU test harness.
2. Disconnect vacuum hose from idle-up VSV and connect a suitable vacuum pump.
3. If 4 inches of vacuum cannot be applied replace the idle-up VSV.
4. With all accessories off and ignition switch at ON position, ensure vacuum bleeds off and becomes zero.
5. If vacuum does not bleed off, ensure battery voltage is between ECU test harness terminals 37 and 39.
6. If no voltage is present, ensure resistance between the terminals on the idle-up VSV is 30-50 ohms.
7. If resistance is not as specified, replace idle-up VSV.
8. If resistance is as specified, check wiring between ECU and main relay. Repair as necessary.
9. Start engine.
10. After 60 seconds, apply 4 inches of vacuum. If vacuum can not be applied, check and repair wiring between the idle-up VSV and ECU.
11. When wiring is normal, ensure battery voltage exists between terminals 17 and 39 on ECU test harness.
12. If voltage exists, check wiring between the headlamp switch and/or the defogger switch and the ECU.
13. Turn on headlamps and/or defogger switch. Ensure vacuum applied in step 10 becomes zero.
14. If vacuum fails to become zero, proceed as follows:
a. Check for battery voltage between ECU test harness terminals 17 and 39.
b. If no voltage exists, check wiring between headlamp and/or defogger switch and ECU. Repair as necessary.
c. If voltage exists, perform ECU test as outlined under ``System Diagnostic Check.''
15. Turn headlamp and/or defogger switch off, apply 4 inches of vacuum to idle-up VSV.
16. Turn blower fan switch On. Ensure vacuum being applied returns to zero.
17. If vacuum fails to return to zero, check wiring between idle-up VSV and blower fan switch. Repair as necessary.