Idle Speed/Idle Air Control (IAC) Duty 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.
- 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. Connect SUZUKI scan tool to DLC with ignition switch OFF, if it is available.

Special Tools
(A): SUZUKI scan tool
(B): Mass storage cartridge
(C): 14116 pin DLC cable

2. Warm up engine to normal operating temperature.
3. 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 monitor (Diag.-1) connector and connect duty meter between "Duty output terminal" and "Ground terminal" of monitor (Diag.-1) connector.

NOTE: Above duty values are ON duty (high voltage rate of duty cycle) meter indications.




If duty and/or idle speed is out of specifications, inspect idle air control system referring to Diagnostic Flow Table B-4 IDLE AIR CONTROL SYSTEM CHECK.

4. Remove service wire from monitor (Diag.-1) connector.
5. Install cover to relay box.
6. Check that specified engine idle speed is obtained with A/C ON if vehicle is equipped with A/C.
If not, check A/C signal circuits and idle air control system.