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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 (see GENERAL TROUBLESHOOTING INFORMATION )
  1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
  2. Clear the DTC with the HDS
  3. Start the engine Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle for 20 seconds or more
  4. Check for these conditions in the DATA LIST with the HDS
    • ECT SENSOR 1 above 158°F (70°C)
    • IAT SENSOR above 32°F (0°C)
    • VSS is 0 mph (0 km/h)
    • ST FUEL TRIM between 0 73 and 1 47
    • FSS is CLOSED
  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, go to step  15 If the screen indicates EXECUTING, keep idling until a result comes on If the screen indicates OUT OF CONDITION, go to step  4 and recheck

  6. Remove the intake air duct from the throttle body
  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 (see THROTTLE BODY CLEANING ) Also check for damage to the air cleaner element (see AIR CLEANER ELEMENT INSPECTION/REPLACEMENT ), then go to step  9 If there is damage in the throttle bore, go to step 8

    NO  -Check the A/C system or the power steering system, then go to step  17

  8. Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION )
  9. Reset the PCM with the HDS
  10. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE )
  11. Start the engine Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle for 20 seconds or more
  12. Check for these conditions in the DATA LIST with the HDS
    • ECT SENSOR 1 above 158°F (70°C)
    • IAT SENSOR above 32°F (0°C)
    • VSS is 0 mph (0 km/h)
    • ST FUEL TRIM between 0 73 and 1 47
    • FSS is CLOSED
  13. Check for Pending or Confirmed DTCs with the HDS

    Is DTC P0506 indicated? 

    YES  -Go to step  1 and recheck

    NO  -Go to step 14

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

    Does the screen 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 screen indicates FAILED, check the A/C system and/or the power steering system, then go to step  1 If the screen indicates EXECUTING, keep idling until a result comes on If the screen indicates OUT OF CONDITION, go to step  12

  15. Remove the intake air duct from the throttle body
  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 (see THROTTLE BODY CLEANING ) Also check for damage to the air cleaner element (see AIR CLEANER ELEMENT INSPECTION/REPLACEMENT ), 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, 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 screen indicate PASSED? 

    YES  -Intermittent failure, the system is OK at this time

    NO  -If the screen indicates FAILED, check the A/C system and/or the power steering system, then go to step  1 If the screen indicates EXECUTING, keep idling until a result comes on If the screen indicates OUT OF CONDITION, go to step  12