Idle Air Control (IAC) Valve
- Check idle speed following procedures in ADJUSTMENTS
article. If idle speed is as specified, go to next step. If idle speed is not as specified, follow procedures in DTC P0505 in appropriate BASIC TESTING
article. Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in appropriate TESTS W/CODES
article.
- With engine running, turn headlights on. If idle remains at specified idle speed, system is okay. If idle speed is not within specification, go to next step.
- Turn ignition off. Disconnect IAC valve harness connector. Using an ohmmeter, measure resistance of opening coil and closing coil of IAC valve. See Fig 1
. If resistance is 18.8-22.8 ohms at 68°F (20°C), go to next step. If resistance is not as specified, replace IAC valve. Retest system.
- Using fused jumper wires, connect battery voltage to terminal No. 2 of IAC valve. Connect terminal No. 1 to ground. Open throttle valve and blow air into IAC valve hose. Air should flow through valve. Switch ground lead to terminal No. 3. Air should not flow through IAC valve. Replace IAC valve if it does not operate as specified. If IAC valve does operate as specified, check Red/White wire, Red/Yellow wire, or Red/Black wire between IAC valve and PCM for an open or short. Repair as necessary. If wires are okay, replace PCM. Retest system.
Courtesy of SUZUKI OF AMERICA CORP.