Air Flow Sensor HH-MAF1717
HEHUA NO.: HH-MAF1717
HYUNDAISONATA V (NF) (2005/01 – 2010/12)
SONATA V (NF) 3.3 G6DB 3342 171 233 Saloon 05/01 – /
SONATA V (NF) 3.3 G6DB 3342 184 250 Saloon 08/01 – /
SONATA V (NF) 3.3 G6DB 3342 173 235 Saloon 05/06 – /
HYUNDAIGRANDEUR (TG) (2005/04 – /)
GRANDEUR (TG) 3.3 G6DB 3342 173 235 Saloon 05/04 – /
HYUNDAISANTA Fé II (CM) (2005/10 – /)
SANTA Fé II (CM) 2.7 V6 GLS G6EA 2656 139 189 Closed Off-Road Vehicle 06/03 – /
SANTA Fé II (CM) 2.7 V6 GLS 4×4 G6EA 2656 139 189 Closed Off-Road Vehicle 06/03 – /
KIASORENTO I (JC) (2002/08 – /)
SORENTO I (JC) 3.3 V6 3297 177 241 Closed Off-Road Vehicle 06/12 – /
SORENTO I (JC) 3.3 V6 4WD G6DB 3342 182 248 Closed Off-Road Vehicle 07/11 – /
KIAOPIRUS (GH) (2003/09 – /)
OPIRUS (GH) 3.8 V6 G6DA 3778 196 267 Saloon 06/10 – /
KIAMAGENTIS (MG) (2005/10 – /)
MAGENTIS (MG) 2.7 V6 G6EA 2656 142 193 Saloon 09/07 – /
MAGENTIS (MG) 2.7 G6EA 2656 138 188 Saloon 05/11 – /
KIACARNIVAL / GRAND CARNIVAL III (VQ) (2005/09 – /)
CARNIVAL / GRAND CARNIVAL III (VQ) 2.7 V6 G6EA 2656 139 189 MPV 06/06 – /
Working principle of the MAF sensor
MAF sensor which measures the mass of air flow – Hot Wire sensor
Sensor of this type is shown in fig. 3. Hot wire (2) with diameter of 70μm is mounted in a measuring tube located before the throttle valve.
Operation of MAF is based on the principle of constant temperature. Heated platinum wire, suspended in the engine’s air stream (3), is one of the legs of a Wheatstone bridge. Constant temperature of approximately 100 ºС is maintained by increasing or decreasing the electrical current flowing through the circuit while the incoming airflow cools the wire.
By increasing the airflow, platinum wire gets cool and its resistance decreases. The Wheatstone resistor bridge is asymmetrical and a voltage appears which is submitted to an amplifier and directed to raise the wire temperature. This process continues until the temperature and resistance of the conductor does not lead to system balance. The current range is 0.5A – 1.2А.
This current also flows through a calibration resistor and forms a voltage drop which enters the onboard controller for calculation of the quantity of the injected fuel. Changes of temperature are compensated by the resistor (4), which is a platinum ring, suspended into the air stream. The temperature changes simultaneously influence both the heated resistance conductor (2) and the temperature compensation resistor (4), and thus the Wheatstone resistor bridge remains balanced.
During operation the platinum wire inevitably pollutes. To prevent the pollution after turning off the engine, the wire is heated to a temperature of 1000 º C for 1 sec. Thus all the dirt stick to the wire is burned. This process is controlled by the onboard controller.
MAF sensor which measures the mass of air flow – Hot Film sensor (HFM)
Hot-film MAF sensors function much like a hot wire sensor, and used a centrally-heated film or metallic grid-type element. One side of the film encounters cooling airflow, while the shielded backside maintains a consistent temperature, and the current differential between the two is measured and relayed as a square-wave digital frequency output, between around 30Hz at idle and 150Hz at wide-open throttle. Hot film sensors tend to be more robust and less susceptible to contamination than hot-wire types.
MAF sensor for volume consumption of air – VAF sensor
Sensors for volume consumption of air (fig.5) have an air barrier (4) equipped with a return spring. This barrier is placed into the airflow consumed by the engine and is moved proportionately with increasing or decreasing the airflow.
The sensor is also equipped with an additional barrier (2), which serves not only for balance but as damper against fluctuations.
The barrier is mechanically connected to the potentiometer wiper (3). Supply voltage is fed to the potentiometer. Its output voltage depends on the position of the barrier position and the barrier position itself depends on the volume of the airflow.
Sensor’s measuring potentiometer is made on a ceramic substrate. The voltage divisor resistor’s terminals are made on the substrate and are arranged in a row and covered with a resistive layer.
Potentiometer wiper is pressed to the contact resistive layer and due to the electrical contact betw