P0101

P0101

Mass Air Flow Circuit. Performance Problems.







Fault symptoms
- CHECK ENGINE

On-Board Diagnostics

Type of diagnosis:
- Continuous. Ceases when fault criteria fulfilled. Restarts next driving cycle.

Enable criteria:
- General condition for this diagnostic trouble code: Atmospheric pressure must exceed 72 kPa as well as coolant and intake air temperature must exceed -7 degree C.
- Main relay voltage exceeds 10V. Speed above 45 km/h for longer than 60 s accumulated time. Coolant temperature between 78 and 115 degree C. Engine speed between 700 and 4000 rpm. Purge active. No fuel shut-off. No change in bypass valve status. Pressure ratio for pressure after and before the throttle between 0.2 and 0.7. Throttle opening between 50 and 500 sq. mm. Even engine load.
- Mass air flow is calculated using the throttle valve angle and pressure difference before and after the throttle.

Fault criteria:
- Conditions for test 1, 2, 3 or 4 fulfilled.
- Test 1: Mass air flow sensor indicates more than 12% lower value than that calculated while the multiplicative adaptation is greater than 17%.
- Test 2: Mass air flow sensor indicates more than 12% higher value than that calculated while the multiplicative adaptation is lower than -17%.
- Test 3: Mass air flow sensor indicates more than 30% lower value than that calculated.
- Test 4: Mass air flow sensor indicates more than 30% higher value than that calculated.

Dependents:
- P0112, P0113, P0106, P0107, P0108, P1105, P1106, P1107, P1108, P1230, P0501, P0502, P1625, P0444, P0445.

System reaction to a fault:
- Fuel adaptation reset. Intake pressure and intake air temperature used as substitute values.

OK report:
- Enable criteria fulfilled without fault reports

Fault handling: (For more information, Fault Handling III, Other Emission-Related Components and Function)

- Type III.

Diagnostic help
DTC indicates leak between mass air flow sensor and throttle body or fault in mass air flow sensor.

Functions in the diagnostic tool related to the fault:
- Diagnostic status for the diagnosis.
- Air mass deviation from calculated, unit %.