P1092

P1092

Hot-film mass air flow meter - above/below limit value

Diagnostic conditions
- Supply voltage 10 V ... 16 V
- Engine start

Possible fault causes
- Open circuit, short circuit to B+ or short circuit to ground in sensor line to hot-film mass air flow meter
- Open circuit in power supply line (12V), ground supply line or sensor power supply line (5V) to the hot-film mass air flow meter
- Hot-film mass air flow meter faulty
- DME control module faulty

Function description

Diagnosis of plausibility of MAF sensor signal
- The measured value supplied by the MAF sensor is compared to a value from a map. This map is determined by engine speed, throttle valve position, ambient pressure and intake air temperature.
- The mass air flow upstream of the throttle valve is identified as implausible if the measured value deviates too greatly from the map.
- If the switching cups stick on a small stroke on one or both banks (e.g., oil duct blocked), the MAF sensor can also be detected as faulty. This is because the expected increase in the air-flow rate does not occur.
- The monitoring of electrical faults (open circuit, short circuit) takes place in a separate diagnosis.