P1094

P1094

Diagnosis information - DME V8 DFI

Implausible mass air flow ahead of throttle valve

NOTE: For this fault code, the intake system between the hot-film mass air flow sensors (MAF 1 + 2) and the throttle is monitored.

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 MAF sensors.
- Any deviation may be due to both the calculated mass air flow and the measured mass air flow.

Diagnostic conditions
- Vehicle voltage > 9 V
- Engine running
- No electrical MAF sensor fault
- 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 switch-over fault

Possible fault causes
- Hot-film mass air flow sensor soiled/faulty (displaced characteristic)
(setpoint voltage with stopped engine and ignition on = 0.9 ... 1.1 V
- see Actual values, Filter [MAF], [Mass air flow 1 (sensor)] + [Mass air flow 2 (sensor)])
- Fault in the area of valve lift, camshaft adjustment, intake manifold, intake manifold switch-over, throttle valve, ambient pressure sensor, intake air temperature sensor, speed sensor
- Changed air flow to hot-film mass air flow sensor due to:
- Foreign matter ahead of hot-film mass air flow sensor
- Hot-film mass air flow sensor twisted
- Leak just ahead of hot-film mass air flow sensor
- Clogged air cleaners
- Exhaust system faulty - flow severely restricted
- Leakage between MAF sensor and throttle valve adjusting unit
- Plug connection on the hot-film mass air flow sensor oxidized / faulty.