MAFS (Mass Air Flow Sensor) has a built-in intake air temperature sensor and is located between the air cleaner assembly and the throttle device. The MAFS uses a hot film type sensing-element to measure the mass of intake air entering the engine. And send the signal to ECM.
A large amount of intake air represents acceleration or high load conditions while a small amount of intake air represents deceleration or idle.
The ECM uses this information to control the EGR solenoid valve and correct the fuel amount.
If the signal exceeds threshold value, the ECM judges this as a fault and DTC is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Voltage range check
? Short to battery in signal circuit
? Short to battery in power circuit
? Faulty MAFS
? Faulty ECM
Enable Conditions
? Engine run
Threshold Value
? 4.7 V < Sensor supply voltage < 5.1 V
Diagnostic Time
? 0.1 sec.
MIL
Fuel Limit
Fuel Cut
EGR Off
? Yes
? No
Fail safe
? EGR valve deactivited
? Fuel quantity limitation
MAFS
Idle Position (without EGR)
Idle Position (with EGR)
Mass air flow
450~550 mg/stroke
280~360 mg/stroke