P1091

P1091

Hot-film Mass Air Flow Sensor (MAF) - Above Limit Value

Diagnostic conditions
- Battery voltage greater than 8 V
- Engine running
- Engine temperature greater 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 hot-film mass air flow sensor plug

Diagnosis/fault finding







Hot-film mass air flow sensor