4BC0

4BC0 - P0103

Information saved in
DDE

Fault code
4BC0 - P0103

Fault text
DDE: Air-mass flow sensor: Air mass too low (signal
frequency too low)

Fault description
Mass airflow sensor sensor-monitoring function. The
diagnostic trouble code is logged in the ECU when the
period duration of the raw sensor signal exceeds 833 us.

Condition for fault identification
Test condition:
The test is conducted under the following conditions:
- Engine rpm exceeds 590 1/min.
- No electrical faults stored for the HFM.
- Power is being supplied to the mass-airflow sensor
(Terminal 15 = On).
Voltage condition:
The test is conducted under the following conditions:
- Engine rpm exceeds 590 1/min.
- No electrical faults stored for the HFM.
- Power is being supplied to the mass-airflow sensor
(Terminal 15 = On).

Condition for fault memory entry
Debounce (150 ms)

Action in service
1. Check wires, plug connections and electrical power
supply.
2. If the wires, plugs and voltage supply are all ok:
Replace mass-airflow sensor.

Fault effect and breakdown warning
Proceed to the nearest BMW Service facility.

Driver information
Warning light:
MIL

Service instruction
none