P0506

DTC P0506: Idle Control System RPM Lower Than Expected

NOTE: If DTC P0511 is stored at the same time as DTC P0506, troubleshoot DTC P0511 first, then recheck for DTC P0508.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle for 20 seconds.
4. Check this data in the DATA LIST with the HDS:
- Engine coolant temperature more than 158 °F (70 °C)
- Intake air temperature more than 18 °F (-7.6 °C)
- Vehicle speed is 0 mph (0 km/h)
- FSS is CLOSED
- ST FUEL TRIM between 0.65 and 1.47

5. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES - Go to step 6.

NO - If the screen indicates PASSED, intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IAC valve and the ECM/PCM. If it is EXECUTING, keep the engine idling until a result comes on. If the screen indicates OUT OF CONDITION, recheck with a different load condition (electrical, A/C, gear position, etc.), then go to step 3.

6. Clear the DTC with the HDS.
7. Do the IAC TEST in the INSPECTION MENU with the HDS.

Is the result OK?

YES - Check the A/C system and the power steering system, then go to step 10.

NO - Go to step 8.

8. Turn the ignition switch OFF.
9. Replace the IAC valve.
10. Turn the ignition switch ON (II).
11. Reset the ECM/PCM with the HDS.
12. Do the ECM/PCM idle learn procedure. Programming and Relearning
13. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle for 20 seconds.
14. Check this data in the DATA LIST with the HDS:
- Engine coolant temperature more than 158 °F (70 °C)
- Intake air temperature more than 18 °F (-7.6 °C)
- Vehicle speed is 0 mph (0 km/h)
- FSS is CLOSED
- ST FUEL TRIM between 0.65 and 1.47

15. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0506 is indicated, check for poor connections or loose terminals at the IAC valve and the ECM/PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Go to step 16.

16. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the IAC valve and the ECM/PCM, then go to step 1. If the screen indicates EXECUTING, keep the engine idling until a result comes on. If the screen indicates OUT OF CONDITION, recheck with a different load condition (electrical, A/C, gear position, etc.), then go to step 13.