Idle Air Control Valve

Idle Air Control (IAC) Valve Connector:

1. Start the engine and run it at idle.
2. Disconnect the IAC valve connector and verify that the engine speed changes.
3. If the engine condition does not change, do as follows.

NGS Connected To DLC-1 And Battery:

Using the SSTs (NGS)
1. Connect the Idle Air Control (IAC) valve connector.
2. Connect the Special Service Tools (SST)s New Generation Star (NGS) tester to the data link connector and battery.
3. Verify that diagnostic trouble code No. P0505 is not displayed. If code No. P0505 is shown, carry out troubleshooting of the code No. P0505.
4. Warm up the engine to normal operating temperature and run it at idle.
5. Select the "SIMULATION TEST" function on the NGS display. Change the duty value of the IAC valve to 100% by using the "IACV" and verify that the idle speed increases.
(1) If the idle speed increases, replace the PCM.
(2) If the idle speed does not change, replace the BAC valve.

6. (California 2WD)
Select the "SIMULATION TEST" function on the NGS display. Change the duty valve of the Bypass air solenoid valve from OFF to ON by using the "AWS" and verify that the idle speed increases.
(1) If the idle speed increases, replace the PCM.
(2) If the idle speed does not change, replace the Bypass air solenoid valve.

Idle RPM Load Chart:

7. Turn the electrical loads ON and verify that the engine speed is within the specification by using "PID/DATA MONITOR AND RECORD" function.

NOTE: Excludes temporary idle speed drop just after the electrical loads are turned on.

8. If not as specified, check the related switches and wiring harnesses.




1. Verify that the ignition switch is OFF.
2. Disconnect the idle air control valve connector.
3. Measure the resistance of the idle air control valve by using an ohmmeter.

Specification: 10.7 - 12.3 Ohms @ 2O°C (68°F)

4. If not within the specification, replace the BAC valve.