Idle Speed and IAC Throttle Valve Opening Inspection

Before idle speed check, make sure of the following.

Lead wires and hoses of electronic fuel injection and engine and emission control systems are connected securely.
Valve lash is checked 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.
There are no abnormal air drawn in from air intake system.
There are no obstruction in PCV valve or its hoses.

After all items are confirmed, check idle speed and IAC throttle opening 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 (1) with ignition switch turned OFF.
Special Tool

(A): SUZUKI scan tool (SUZUKI-SDT)

Fig 1: Identifying Data Link Connector And Scan Tool
Courtesy of SUZUKI OF AMERICA CORP.
Warm up engine to normal operating temperature.
Check engine idle speed and "IAC throttle opening" by using "Data List" mode on scan tool to check "IAC throttle opening".
If check result is out of specification, inspect the followings.
- EVAP canister purge control system referring to EVAP CANISTER PURGE INSPECTION .
- Electric load signal circuit referring to ELECTRIC LOAD SIGNAL CIRCUIT CHECK .
- PCV system referring to PCV HOSE INSPECTION .
- Electric throttle body assembly referring to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Engine idle speed and IAC throttle opening

A/C OFF: 680 - 780 rpm, 10 - 20%

A/C ON: 750 - 850 rpm, 15 - 25%
Check that specified engine idle speed is obtained with A/C turned ON if vehicle is equipped with A/C. If not, check A/C system referring to A/C SYSTEM CIRCUITS CHECK .