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 clearance has been is checked according to maintenance schedule.
Ignition timing is within specification.
All electrical systems (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.
There are no DTC in ECM.
Check following item turn OFF by using "Data List" mode on scan tool.
- A/C Comp Relay
- A/C Switch
- Brake Switch
- PSP Switch (P/S signal)
- Electric Load
- Blower Fan

After confirming all items, check idle speed and IAC throttle opening as follows.

NOTE: Before starting engine, place gear shift lever in "Neutral" (M/T model) or selector lever in "P" range (A/T model), and set parking brake and block drive wheels.

Turn OFF ignition switch and connect SUZUKI scan tool to DLC (1).
Special Tool

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

Fig 1: Connecting SUZUKI Scan Tool To DLC
Courtesy of SUZUKI OF AMERICA CORP.
Warm up engine to normal operating temperature.
Check engine idle speed and "IAC throttle opening" using "Data List" mode on scan tool.
If check result is out of specification, inspect the following.
- Ignition timing: IGNITION TIMING INSPECTION
- Improper engine idle speed referring to "Improper engine idling or engine fails to idle" in
- EVAP canister purge control system: EVAP CANISTER PURGE SYSTEM INSPECTION
- PCV system: PCV HOSE INSPECTION
- Throttle body assembly: THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION
  Engine idle speed
  
  A/C OFF: 630 - 730 RPM (IAC throttle opening: 10 - 20%)
  
  A/C ON: 800 - 900 RPM (IAC throttle opening: 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.