Idle Air Control (IAC) Valve Check

1. Disconnect connector from IAC valve.
2. Check for proper connection to IAC valve at each terminal.
3. Check IAC valve for resistance.

Resistance between two terminals: 8.6 - 10.6 ohms at 20 °C, 68 °F

Resistance between terminal and valve body: Infinity

If check results are as specified in steps 2) and 3), proceed next step. If not, replace.




4. Connect connector to IAC valve.
5. Warm up engine to normal operating temperature.
6. Disconnect connector from IAC valve and check engine idle speed.




7. Connect 12 V-battery to IAC valve as shown in figure with engine running and check engine idle speed.

CAUTION: Wrong connection cause IAC valve to burn, connect each wire to correct terminal.

Engine idle speed observed in step 7) should be higher than engine idle speed observed in step 6).

If check result is not specified, replace IAC valve.