P0103
P0103Main filling signal (MAF) - above limit value
Diagnostic conditions
- Battery voltage > 8 V
- Engine running
- Engine temperature higher than 60 °C
- Test drive of approx. 20 minutes with changing load conditions
Possible fault cause
- Hot-film mass air flow sensor 1 and / or 2 faulty (setpoint voltage with stopped engine and ignition on = 0.9 to 1.1 V) --> see Actual values, Filter [[DME mass air flow]], [[Mass air flow 1 (sensor)]] + [[Mass air flow 2 (sensor)]]
- Short circuit to B+ in signal line
- Short circuit to B+ in sensor voltage
- DME control unit faulty
Affected pins
DME control unit plug A, pin 27, and pin 3 of hot-film mass air flow sensor plug
DME control unit plug A, pin 53, and pin 4 of hot-film mass air flow sensor plug
DME control unit plug A, pin 29, and pin 5 of plug for hot-film mass air flow sensor 1
DME control unit plug B, pin 109, and pin 5 of plug for hot-film mass air flow sensor 2
Diagnosis/fault finding
Hint:
If the connector A is disconnected from the DME control unit and the ignition is switched on or was switched on, the fault >>DME control unit Timeout<< is entered in many control units
Hint:
If the control unit connector A was disconnected from the BME during fault finding or if the power supply was interrupted elsewhere (battery, fuse), adaptation of the throttle valve adjusting unit must be performed.
Hint:
If this fault is set, both hot-film mass air flow sensors must always be tested because the main filling signal is calculated from both signals.
