Ignition "OFF"
Remove ISC Valve from Throttle body
Ignition "ON" & Engine "OFF".
Install scan tool and select "ISC Valve" parameter on the "Actuation Test" mode.
Activates ISC valve by pressing "STAT" key
Check the ISC valve for clicking sound and visually verifying valve closes and opens
Repeat numerous times to ensure valve reliability
Is ISC Valve OK?
YES
Thoroughly check connectors for loose or poor connections, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure
NO
Check for open or short circuit in harness and repair as necessary. If OK, test with a new ISC valve and check for proper operation. If problem is corrected, replace ISC valve. Go to "Verification of Vehicle Repair" procedure