Idle Speed Control (ISC): DOHC
- Before idle speed/ISC duty is checked or adjusted, ensure all wires and vacuum hoses are connected securely, accelerator cable has some play, valve clearance and timing are set to specification, and all accessories are turned off.
- Warm engine to normal operating temperature. Connect tachometer. Using a service wire, connect terminal "D" (ground) and terminal "B" (diagnostic switch). Ensure CHECK ENGINE light indicates a Code 12. Connect duty meter between terminal "D" (ground) and terminal "F" (duty output). If idle speed and ISC duty are not within specification, remove adjusting screw protective cap and adjust idle speed by turning adjusting screw. See ADJUSTMENTS article in the ENGINE PERFORMANCE Section. Replace ISC solenoid if defective. If ISC solenoid is okay, go to next step.
- If vehicle is equipped with A/C, go to step 4). If vehicle is not equipped with A/C, replace adjusting screw protective cap and remove service wire.
- Turn A/C on, and set heater blower switch to high (maximum) speed. With A/C working properly, ensure idle speed and ISC duty are within specification. If idle speed and/or ISC duty are not within specification, adjust at A/C Vacuum Switching Valve (VSV). See ADJUSTMENTS article in the ENGINE PERFORMANCE Section. Replace ISC solenoid and/or A/C VSV if defective. Remove service wire. Replace adjusting screw protective cap if removed.