Idle Speed/Throttle Actuator - Electronic: Adjustments

Before idle speed/Idle Air Control (IAC) duty check and adjustment, make sure of the following.
- Lead wires and hoses of Electronic Fuel Injection and engine emission control systems are connected securely.
- Accelerator cable has some play, that is, it is not tight.
- Valve lash is checked and adjusted according to maintenance schedule.
- Ignition timing is within specification.
- All accessories (wipers, heater, lights, A/C, etc.) are out of service.
- Air cleaner has been properly installed and is in good condition.
- No abnormal air inhaling from air intake system.
After above items are all confirmed, check idle speed and IAC duty as follows:

NOTE: Before starting engine, place transmission gear shift lever in "Neutral" (shift selector lever to "P" range for A/T vehicle), and set parking brake and block drive wheels.

1. Warm up engine to normal operating temperature.





2. Using service wire, ground diagnosis switch terminal in diagnosis connector 1 and make sure that malfunction indicator lamp ("CHECK ENGINE" light) indicate diagnostic trouble code No.12. The diagnosis connector 1 is located in the relay box.
3. Stop engine and connect duty meter between duty output terminal and ground terminal in diagnosis connector 1.
4. Set tachometer.
5. Start engine and warm it up completely.
6. Check IAC duty and idle speed. If duty and/or idle speed is out of specifications, inspect idle air control system.





NOTE:
- Above duty values are ON duty meter indications.
- Duty values with (*) are applicable to vehicle used at high place (higher than 2,000m or 6,560ft).
- IAC duty can be checked by using analog type voltmeter. IAC duty to voltage relation is as follows:





- "OFF DUTY METER" is such duty meter that indicates approx. 100% when terminal voltage is approx. "0V".
- "Vs" represents battery voltage while engine of vehicle being checked is running.

Adjustment





1. Adjust duty and/or idle speed to specified value by turning idle speed adjusting screw.
2. Upon completion of adjustment, install adjusting screw cap to throttle body.
3. Remove service wire from diagnosis connector 1 and install cover to relay box.
4. Check that specified engine idle speed is obtained with A/C if vehicle is equipped with A/C. If not, check A/C ON signal circuit and idle air control system.