P0101
Read the instructions below then
start the fault diagnostic procedure.
Symptom: CHECK ENGINE.
Mass Air Flow Circuit. Performance Problems.
Fault symptoms
On-Board Diagnostics
Type of diagnosis:
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Continuous. Terminated when fault criteria fulfilled. Restarts next driving cycle.
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Enable criteria:
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General conditions for this trouble code: Atmospheric pressure must exceed 72 kPa and the engine coolant and intake air temperature must be above -70°C.
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Main relay voltage exceeds 10V. Vehicle speed over 45 km/h for longer than 60s accumulated time. Coolant temperature between 78 and 115 °C. Engine speed between 700 and 4000 rpm. Purging active. No fuel shut-off. No change in bypass valve status. Pressure ratio before and after throttle between 0.2 and 0.7. Throttle opening between 50 and 500 mm
2
. Even engine load.
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Mass air flow is calculated using the throttle opening and pressure difference before and after the throttle.
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Fault criteria:
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Conditions for test 1, 2, 3 or 4 fulfilled.
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Test 1:
Mass air flow sensor indicates value more than 12% lower than the calculated while the multiplicative adaptation is higher than 17%.
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Test 2:
Mass air flow sensor indicates value more than 12% higher than the calculated while the multiplicative adaptation is lower than -17%.
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Test 3:
Mass air flow sensor indicates value more than 30% lower than the calculated.
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Test 4:
Mass air flow sensor indicates value more than 30% higher than the calculated.
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Dependents:
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P0112, P0113, P0106, P0107, P0108, P1105, P1106, P1107, P1108, P1230, P0501, P0502, P1625, P0444, P0445.
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System reaction to a fault:
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Fuel adaptation reset. Intake pressure and intake air temperature used as substitute values.
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OK report:
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Enable criteria fulfilled without any faults being reported.
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Fault handling:
(For more information, see
Fault handling III, other emission-related components and functions
.)
Diagnostic help
The diagnostic trouble code indicates a leak between the mass air flow sensor and throttle body or a fault in the mass air flow sensor.
Functions in the diagnostic tool related to the fault:
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Diagnostic status for the diagnosis.
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Air mass deviation from calculated, unit %.
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