1. MAF
MAFS(Mass Air Flow Sensor) is a hot-film type, and is mounted between air-cleaner and throttle body, which measures the amount of air flow getting into the engine. It is composed of tube, sensor assembly, and honey cell. Once the laminar stream which was generated by honey cell flows around the hot-film, the convective heat transfer is generated from hot-film, and the energy loss of MAFS is generated by this heat transfer. ECU calculates the amount of intake air flow using measuring this energy loss.
ECU sets P0101 when the digital MAF sensor signal is abnormal or the error occurs during self-diagnosis, or when the cycle of the sensor signal is abnormal.
Item | Detecting Condition | Possible cause |
DTC Strategy |
•
Check the value of air flow is excessive or deficient.
•
The error occurs during self-diagnosis
•
Check the signal cycle is excessive or deficient. | 1. MAP Sensor 2. Poor connection 3. Open circuit of power line or short circuit to ground 4. Open circuit of signal line or short circuit to ground |
EnableConditions |
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Engine RPM is higher than 580 and lower than 6500.
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Battery voltage is higher than 10V and lower than 16V.
•
Relative quantity of flow of canister in cylinder is lower than 8%.
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Engine oil temperature is lower than 230℉.
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Not fuel cut
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Engine running time is longer than 10 sec.
•
No relative DTCs
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Increase of target value of relative amount of air flow is lower than 10~15%. | |
Threshold value |
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Correction value of intake area is lower than -90~-40% or higer than 40~90%. (dependant on the amount of air flow)
•
Correction value of barometric pressure is lower than -30 % or higher than 30%.
•
No repetition of sensor signal
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No repetition of reference sensor signal
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Voltage of sensor signal is low.
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Voltage of reference sensor signal is high.
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Cycle of sensor signal is shorter than 85 µs.
•
Cycle of sensor signal is longer than 555 µs | |
Diagnosis Time |
•
5 sec | |
MIL On Condition |
•
Second driving cycle (MIL On) |
MAFS(Kg/h) | MAFS signal(Hz) |
10 | 2012.7 |
12 | 2055 |
15 | 2116 |
20 | 2209.4 |
30 | 2370 |
40 | 2507.8 |
50 | 2631.3 |
60 | 2745.6 |
75 | 2906 |
90 | 3508 |
105 | 3204.7 |
120 | 3348.5 |
140 | 3537.9 |
160 | 3727 |
190 | 4013.9 |
Fig. 1) Normal waveform of MAFS at idle. (600rpm & 11kg/h)
Fig. 2) Normal waveform of MAFS at acceleration. (2080rpm & 34kg/h)
Fig. 3) Normal data of MAFS at idle.
Fig. 4) Normal data of MAFS at acceleration.
