The hot-film mass air flow sensor(MAFS) assembly detects the mass air flow quantity for the engine. Mass air flow sensor uses the sensor heater to calculate the intake air quantity, then sends the signal to ECM. ECM then determines the fuel quantity and injection timing, and reconizes uphills and helps fuel quantity and overrun air conditioner compensation, idle speed actuator In addition, Mass air flow sensor is used in feed back control for the EGR system and for the boost pressure control of smoke limit. Mass air flow sensor might be combined to measure the intake air temperature.
If an unusually low or high airflow rate is being read by the MAFS, or there are airflow readings that do not correspond to the expected engine load (too high or too low) during two driving cycles, these codes will be set and the Malfunction Indicator Light (MIL) will be turned on.
DTC NO.
Detecting Condition
Possible Cause
P 0101
P 0102
P 0103
P 0104
? P 0101
Error is recognized if the calculated air quantity is above 1010 mg/st from the MAFS and IAT (intake air temp. sensor) under the condition of engine 2040 < 2690 rpm and injection quantity < 0 mg/st and barometric pressure > 750 hpa and -7?(19.4?) < WTS 120?(248?) only
? P 0102
Output signal < - 25 kg/h air
? P 0103
Output signal > 700 kg/h air
? P 0104
Error is recognized unless the sensor supply voltage is from 4.7 to 5.1V
? Engine Condition : RUN
? Fuel Limit : YES
? Fuel Cut : NO
? EGR OFF : YES
? MIL : YES
? LIMP HOME MODE
? EGR valve deactivition
? Fuel quantity limitation.
? Open or short in circuit
? Fuse
? MAFS
? EGR
? ECM
MAFS
Idle Position (without EGR)
Idle Position (with EGR)
Mass air flow
450 ~ 510 mg/stroke
280 ~ 360 mg/stroke