E39 / P0506 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Malfunction Indicator Lamp
Idle Speed Control. Idling Speed too Low.

Fault symptom
Malfunction Indicator Lamp
On-board diagnosis
Type of diagnosis:
Enable criteria:
| General conditions for this DTC |
| Coolant temperature above 60°C. |
| Intake air temperature above -10.5°C. |
| Secondary air pump must not be active. |
| Idling at least 5 seconds. |
| The idle speed is stable within +/-25 rpm. |
Fault criteria:
| Engine speed below requested idling speed by more than 91 rpm for more than 10 s. |
Diagnostic help
Diagnosis regards:
| Blocked throttle, blocked air supply, short engine mechanical fault. |
| Misfiring when idling will also generate this diagnostic trouble code. |
Functions in the diagnostic tool related to the fault:
| (See also description of readings/activations in diagnostic tool) |