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.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0506 Idle Control System RPM Lower Than Expected
      

1.
Problem verification:

Problem verification
?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 at least 20 seconds.

?4.
Check for these conditions in the DATA LIST with the HDS.
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
IAT SENSOR above 32 °F (0 °C)
VEHICLE SPEED is 0 mph (0 km/h)
AF FB (ST FUEL TRIM) between 0.79 and 1.33
FSS is CLOSED

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
IAT SENSOR (2)
    
VEHICLE SPEED
    
AF FB (ST FUEL TRIM)
    
FSS
    

?5.
Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P0506 Idle Control System RPM Lower Than Expected
  

Does the HDS indicate FAILED?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
If the HDS indicates PASSED, go to step 3. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-4 and recheck.
2.
Throttle body visual check:

Throttle body visual check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Remove the intake air duct from the throttle body.

?3.
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. Also check for damage to the air cleaner element, then do the repair verification. If there is damage in the throttle bore, replace the throttle body, then do the repair verification.
     
NO
     
     
     
The throttle body is OK. Check the A/C system, then go to step 4.
3.
Throttle body visual check:

Throttle body visual check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Remove the intake air duct from the throttle body.

?3.
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. Also check for damage to the air cleaner element, then do the repair verification. If there is damage in the throttle bore, replace the throttle body, then do the repair verification.
     
NO
     
     
     
The throttle body is OK. Go to step 4.
4.
Idle control system check:

Idle control system check
?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 at least 20 seconds.

?4.
Check for these conditions in the DATA LIST with the HDS.
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
IAT SENSOR above 32 °F (0 °C)
VEHICLE SPEED is 0 mph (0 km/h)
AF FB (ST FUEL TRIM) between 0.69 and 1.47
FSS is CLOSED

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
IAT SENSOR (2)
    
VEHICLE SPEED
    
AF FB (ST FUEL TRIM)
    
FSS
    

?5.
Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P0506 Idle Control System RPM Lower Than Expected
  

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 4-4.
Repair verification (OBD STATUS check):

?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.
Reset the PCM with the HDS.


?5.
Do the PCM idle learn procedure.

?6.
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 at least 20 seconds.

?7.
Check for these conditions in the DATA LIST with the HDS.
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
IAT SENSOR above 32 °F (0 °C)
VEHICLE SPEED is 0 mph (0 km/h)
AF FB (ST FUEL TRIM) between 0.79 and 1.33
FSS is CLOSED

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
IAT SENSOR (2)
    
VEHICLE SPEED
    
AF FB (ST FUEL TRIM)
    
FSS
    

?8.
Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P0506 Idle Control System RPM Lower Than Expected
  


Does the HDS indicate PASSED, FAILED, EXECUTING, or OUT OF CONDITION?

     
PASSED
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Go to step 1 and recheck.
     
EXECUTING
     
     
     
Keep idling until a result comes on
     
OUT OF CONDITION
     
     
     
Meet the test condition, and check the OBD STATUS again.