Idle Air Control Operation Inspection

Engine coolant temperature compensation Inspection




1. Connect the SSTs (NGS tester) to DLC-2.
2. Select the PID/DATA MONITOR AND RECORD function on the NGS display.
3. Select the following PIDs.
- ECT
- IACV
- RPM

4. Verify that the engine is in cold condition, then start the engine.
5. Verify that the engine speed decreases as the engine warms up.
- If the engine speed does not decrease or decreases slowly, carry out the following:
- ECT sensor inspection
- IAC valve inspection

Load compensation inspection
1. Start the engine and run at idle.




2. Disconnect the IAC valve connector and verify that the engine rotation changes.
3. If the engine condition does not change, inspect as follows.
1. Connect the IAC valve connector.




2. Connect the SSTs (NGS tester) to DLC-2.
3. Verify that DTC P0506, P0507 or P1504 is not displayed.
- If DTC P0506, P0507 or P1504 is shown, carry out DTC inspection.

4. Select the SIMULATION TEST function on the NGS display.
5. Change the duty value of the IAC valve to 100% using the IACV PID.
6. Verify that the idle speed increases.
- If the idle speed increases, replace the PCM.
- If the idle speed does not change, inspect the following:
- IAC valve air passage
- Open or short circuit between IAC valve connector terminals and PCM connector terminals 54 and 83

4. Warm up the engine to normal operating temperature and run it at idle.
5. Select the PID/DATA MONITOR AND RECORD function on the NGS display.
6. Select the following PIDs.
- A/C SW
- IACV
- PSP SW
- RPM

Engine Speed:

7. Turn the electrical loads on and verify that the engine speed is within the specification.
- If not as specified, carry out the following:
- A/C switch inspection
- P/S pressure switch inspection
- IAC valve inspection

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