DTC Troubleshooting

DTC Troubleshooting: P0506

DTC P0506:

Idle Control System RPM Lower Than Expected

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.

1. Turn the ignition switch to ON (II).

2. Clear the DTC with the HDS.

3. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

4. Check for these conditions in the DATA LIST with the HDS:

- ECT SENSOR 1 above 156 °F (70 °C)
- IAT SENSOR above 32 °F (0 °C)
- VEHICLE SPEED is 0 mph (0 km/h)
- ST FUEL TRIM between 0.69 and 1.47
- FSS is CLOSED

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

Does the HDS indicate FAILED?

YES -

Go to step 6.

NO -

If the HDS indicates PASSED, go to step 15. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 4 and recheck.

6. Remove the intake air duct from the throttle body Removal and Replacement.

7. Check for dirt, carbon, or damage in the throttle bore.

Is there dirt, carbon, or damage in the throttle bore?

YES -

If there is dirt or carbon, clean the throttle body Procedures. Also check for damage to the air cleaner element Testing and Inspection, then go to step 9. If there is damage in the throttle bore, go to step 8.

NO -

Check the A/C system, then go to step 9.

8. Replace the throttle body Removal and Replacement.

9. Reset the PCM with the HDS.

10. Do the PCM idle learn procedure PCM Idle Learn Procedure.

11. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

12. Check for these conditions in the DATA LIST with the HDS:

- ECT SENSOR 1 above 156 °F (70 °C)
- IAT SENSOR above 32 °F (0 °C)
- VEHICLE SPEED is 0 mph (0 km/h)
- ST FUEL TRIM between 0.69 and 1.47
- FSS is CLOSED

13. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0506 indicated?

YES -

Go to step 19.

NO -

Go to step 14.

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

Does the HDS indicate PASSED?

YES -

Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 13, go to the indicated DTC's troubleshooting.

NO -

If the HDS indicates FAILED, go to step 19. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 11 and recheck.

15. Remove the intake air duct from the throttle body Removal and Replacement.

16. Check for dirt, carbon, or damage in the throttle bore.

Is there dirt, carbon, or damage in the throttle bore?

YES -

If there is dirt or carbon, clean the throttle body Procedures. Also check for damage to the air cleaner element Testing and Inspection, then go to step 9. If there is damage in the throttle bore, go to step 8.

NO -

Go to step 17.

17. Recheck with different load conditions (turn on the headlights, the blower motor, the rear window defogger, and/or the A/C, change the gear position, etc.).

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

Does the HDS indicate PASSED?

YES -

Intermittent failure, the system is OK at this time.

NO -

If the HDS indicates FAILED, check the A/C system, then go to step 1 and recheck. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 17.

19. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.

20. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

21. Check for these conditions in the DATA LIST with the HDS:

- ECT SENSOR 1 above 156 °F (70 °C)
- IAT SENSOR above 32 °F (0 °C)
- VEHICLE SPEED is 0 mph (0 km/h)
- ST FUEL TRIM between 0.69 and 1.47
- FSS is CLOSED

22. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0506 indicated?

YES -

Check for poor connections or loose terminals at the throttle body and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 20. If the PCM was substituted, go to step 1.

NO -

Go to step 23.

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

Does the HDS indicate PASSED?

YES -

If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 22, go to the indicated DTC's troubleshooting.

NO -

If the HDS indicates FAILED, check for poor connections or loose terminals at the throttle body and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 20. If the PCM was substituted, go to step 1. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 20.