Computers and Control Systems: Adjustments

Idle Speed / Idle Air Control (IAC) Duty Inspection and Adjustment

Inspection

Before idle speed / IAC duty check and adjustment, make sure of the following.

- Lead wires and hoses of engine and emission control systems are connected securely.
- Accelerator cable has some play, that is, it is not tight.
- All accessories (wipers, heater, lights, A/C, etc.) are out of service.
- Air cleaner has been properly installed and is in good condition.
- Ignition timing is within specification.
- No abnormal air inhaling from air intake system.

After the 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) Connect SUZUKI scan tool to DLC with ignition switch OFF, if it is available.
Special Tool

(A): SUZUKI scan tool (Tech 2 kit)





2) Warm up engine to normal operating temperature.
3) Check engine idle speed and IAC duty as follows:
a) Select "Data List" mode on scan tool to check IAC duty.

Engine idle speed and IAC duty






If duty and/or idle speed is out of specifications, inspect idle air control system referring to Idle Air Control (IAC) System Check Idle Air Control (IAC) System Check.
4) Check that specified engine idle speed is obtained with A/C ON if vehicle is equipped with A/C.

If not, check A/C control circuits and idle air control system.

Adjustment

1) Check idle speed / idle air control (IAC) duty.
2) Adjust duty and/or idle speed to specified value by turning idle air adjusting screw (1).