Component Location
General Description

Mass Air Flow Sensor (MAFS) is digital sensor. Measuring mass of air flow, signal is outputted as frequency(Hz). ECM performs EGR system feed back control with the information of measured mass air flow. (The role of MAFS in diesel engine is different from gasoline engine. Fuel injection quantity is decided by MAFS signal in gasoline engine.) When the amount of EGR gas(contains no oxygen) flowing into combustion chamber increases, the air passing through MAFS(contains oxygen) decreases. Thus, with the output signal change of MAFS accompanied by EGR actuator actuation, ECM determines the amount of recirculated EGR gas quantity.

note

NOx is produced in the reaction of nitrogen and oxygen. If least intake air required for complete combustion flows into combustion chamber by controlling EGR gas(contains no oxygen) which is recirculated to combustion chamber, NOx decreases because there is no supplementary oxygen to react with nitrogen.

DTC Description

P0101 is set 1) when Air mass ratio(real/threshold) above 1.5 or below 0.85 is detected for more than 10 sec.. or 2) short to battery or ground in MAFS or IATS signal circuit is detected for more than 0.58 sec. or 3) short to low or high voltage line in IATS signal circuit is detected for more than 0.6 sec.

DTC Detecting Condition

Item

Detecting Condition

Possible Cause

DTC Strategy

● Voltage monitoring

● MAFS circuit

● MAFS component

Enable Conditions

● Engine running

Threshold Value

● Air mass ratio(real/threshold) above 1.5 or below 0.85 - 10 sec.

● Short to low or high voltage line in IATS signal circuit - 0.6 sec.

● Shrot to battery or ground in MAFS or IATS circuit - 0.58 sec.

Diagnostic Time

● Refer to threshold Value.

Fail Safe

Fuel Cut

NO

EGR Off

YES

Fuel Limit

YES

Check Lamp

OFF

Specification

Intake air quantity (Kg/h)

Output frequency ( KHz )

Deviation [ % ]

20℃

80℃

8

1.97

± 3

10

2.01

2.01

± 2

40

2.50

2.50

± 2

105

3.20

3.20

± 2

220

4.30

± 2

480

7.80

7.80

± 2

560

9.50

± 3

Schematic Diagram
note
To view Flash content, you need to install the appropriate browser extension
Signal Waveform
note

Signal frequency increases as RPM rises.

Яндекс.Метрика