E39 / P0101 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Performance loss.
Mass Air Flowsensor, Performace Problem (Deviation from Calculated Mass Air)
Fault symptom
Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Performance loss.
On-board diagnosis
Type of diagnosis:
Enable criteria:
| Battery voltage must be between 10 - 18 V. |
| Intake air temperature between -20°C and 125°C. |
| Coolant temperature between -7°C and 125°C. |
| Engine speed between 400 and 6000 rpm. |
| • | NONE of the following DTCs must be detected: |
| P0116, P0117, P0118, P0119 |
| P2227, P2228, P2229, P2230 |
Fault criteria:
| The air mass deviates from the calculated air mass, based on the throttle valve angle and engine speed. |
| Fault in the multiplicative adaptation. |
| The air mass deviates from the calculated air mass, based on values from the inlet pressure sensor. |
System reaction to a fault:
| Limp home - Only basic charge pressure |
OK report:
| Fault criteria NOT fulfilled. |
Fault handling:
| (See section Fault handling III, "Other emission-related components and functions" for more information.) |
Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.
Diagnostic help
Diagnosis regards:
| The DTC indicates that the value from the mass air flow sensor has been deemed unreliable after comparison with a calculated value. This could be due to an air leak or a faulty mass air flow sensor. |
| A crankcase ventilation leak may be one reason as to why a DTC is set. Check crankcase ventilation function before starting regular troubleshooting. |
Functions in the diagnostic tool related to the fault:
| • | Requested Throttle Position |
| (See section Fault handling III, "Other emission-related components and functions" for more information.) |
