P0506
P0506-IDLE CONTROL SYSTEM RPM - LOWER THAN EXPECTED
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The engine control system uses many methods to achieve stable idle speed (RPM), and is capable of compensating for unexpected changes in load (accessory devices switching on, etc.). In the event that the engine is incapable of steadily maintaining the desired idle speed, either due to overshooting this target, undershooting, or "hunting", this DTC may be set.
- When Monitored:
With the engine running at idle.
- Set Condition:
Engine speed is consistently at least 50 RPM below the target idle speed.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. CHECK THE ENGINE ACCESSORIES
NOTE: If there are any Transmission DTCs present involving the Torque Converter or lock up operation, perform those diagnostic procedures before continuing.
1. Visually inspect the engine accessories for damage, binding or dragging.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.
No
- Go To 2
2. CHECK THE INTAKE SYSTEM
1. Visually inspect the entire Intake System for a restriction.
Were any restrictions found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.
No
- Go To 3
3. CHECK THE EXHAUST SYSTEM
1. Visually inspect the entire Exhaust System for a restriction.
Were any restrictions found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.
No
- Go To 4
4. CHECK THE FUEL DELIVERY SYSTEM
1. Checking The Fuel Delivery System Perform the CHECKING THE FUEL DELIVERY SYSTEM diagnostic procedure.
Were any problems found?
Yes
- Perform the appropriate repair.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test