P1098

P1098

Diagnosis information - DME (DFI)

Implausible mass air flow ahead of throttle valve

NOTE: This fault code is used for monitoring the intake system between the hot-film mass air flow (MAF) sensor and the throttle valve.

NOTE:
- A mass air flow is calculated from the signals from the throttle potentiometer, engine speed sensor, intake air temperature sensor and ambient pressure sensor as well as other engine operating values.
- The calculated mass air flow is compared with that measured by the mass air flow (MAF) sensor.

Diagnostic conditions
- Throttle valve was adapted under the right conditions
(including: intake air temperature less than 40 °C (104 °F))
- Engine running
- No electrical fault for hot-film mass air flow sensor (MAF)
- No throttle valve adjusting unit fault
- No ambient pressure sensor fault
- No intake air temperature sensor fault
- No speed sensor fault
- No valve lift fault
- No camshaft adjustment fault
- No intake manifold switchover fault

Possible fault causes
- Hot-film mass air flow (MAF) sensor soiled/faulty (displaced characteristic) (setpoint voltage with stopped engine and ignition on = 0.9 ... 1.1 V
--> see Actual values, Filter [H_Mass air flow flow], [H030_Mass air flow sensor 1 (sensor)])
- Air flow onto hot-film mass air flow (MAF) sensor deflected