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 ● Yes ● No ● Yes | |
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 |
