Idle Speed / Idle Air Control (IAC) Duty Inspection
Before idle speed/IAC duty check, 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.
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.
2) Warm up engine to normal operating temperature.
3) Check engine idle speed and “IAC duty” as the follows:
a) When using SUZUKI scan tool:
i) Select “Data List” mode on scan tool to check “IAC duty”.
Special Tool
(A) : SUZUKI scan tool
b) When using duty meter (3):
IAC duty can be checked using monitor connector only for engine not equipped with VVT system.
i) Set tachometer.
ii) Using service wire (2), ground “Diag. switch terminal” in monitor connector (1) and connect duty meter between “Duty output terminal (4)” and “Ground terminal (5)” of monitor connector (1).
[A]: When using SUZUKI scan tool [B]: When using duty meter
4) If duty and/or idle speed is out of specifications, inspect idle air control system referring to Idle Air Control System Check:M13A without VVT .
Engine idle speed
M/T vehicle :
A/C OFF : 700 ± 50 r/min (rpm) (IAC duty: 5 – 25%)
A/C ON : 850 ± 50 r/min (rpm)
A/T vehicle at P/N range :
A/C OFF : 750 ± 50 r/min (rpm) (IAC duty: 5 – 25%)
A/C ON : 875 ± 50 r/min (rpm)
Above duty values are ON duty (low voltage rate) meter indications.
5) Remove service wire from monitor connector.
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 ON signal circuit and idle air control system.