Idle Speed: Testing and Inspection

Before idle speed/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.





- Connect SUZUKI scan tool to DLC with ignition switch OFF, if it is available.
- Warm up engine to normal operating temperature.
- Check engine idle speed and "IAC duty" as follows:
When using SUZUKI scan tool:
1. Select "Data List" mode on scan tool to check "IAC duty".
When using duty meter:
1. Disconnect scan tool from DLC if connected.
2. Using service wire, ground "Diag switch terminal" in Diag.-1 connector and connect duty meter between "Duty output terminal" and "Ground terminal" of Diag.-1 connector.





If duty and/or idle speed is out of specifications, inspect idle air control system referring to Non Trouble Code Charts - B-4 Idle Air Control System Check.

NOTE:
- Above duty values are ON duty meter indications.
- Duty values with (*) are applicable to vehicle used at high altitude (higher than 2,000 m or 6,560 ft).
- Remove service wire from Diag.-1 connector.
- Install cover to relay box.
- Check that specified engine idle speed is obtained with A/C ON if vehicle is equipped with A/C. If not, check A/C ON signal circuit and idle air control system.