Contents: Checking the MAFS signal shape ⇓ MAFS Characteristics ⇓ Checking the air temperature sensor ⇓ IATS Characteristics ⇓ Checking the wiring ⇓
Checking the MAFS signal shape
The ECM constantly compares the signals from the air flow sensor and the throttle position sensor. During acceleration, the sensor output voltage increases, and during braking, it decreases
MAFS Characteristics
Air flow sensor
| Air consumption, kg/h (at 20°C) | Voltage, V |
| 4,9 | 0,7 |
| 7,3 | 0,9 |
| 12,2 | 1,18 |
| 20,8 | 1,51 |
| 28,3 | 1,73 |
| 38,9 | 1,97 |
| 64,7 | 2,4 |
| 113,3 | 2,9 |
| 185,3 | 3,35 |
| 256,0 | 3,64 |
| 494,0 | 4,07 |
| 476,7 | 4,25 |
| 603,3 | 4,65 |
Note: If the output voltage is 0.0V or 5.0V, it means the sensor is damaged and needs to be replaced.
Checking the air temperature sensor
Measure the resistance of the sensor circuit between pins 1 and 5 and compare the result with the table below.
IATS Characteristics
| Temperatures | Resistance |
| -40°C | 41.26-47.49 kOhm |
| -20°C | 14.26-16.02 kOhm |
| 0°C | 5500-8050 Ohm |
| 20°C | 2350-2540 Ohm |
| 40°C | 1110-1190 Ohm |
| 80°C | 310-320 Ohm |
Checking the wiring
With the ignition on, measure the voltage between the specified contacts of the wire portion of the connector.
| Circuit under test | Nominal voltage |
| Contact 2 - "ground" | B+ |
| Contact 5 - "ground" | 5 V |
| Contact 2 - Contact 4 | Below B+ by about 200 mV |
| Contact 1 - Contact 2 | |
| Contact 1 - Contact 5 |
1. Sensor "mass"
2. Nutrition (B+)
3. Air flow signal
4. "Mass"
5. Air temperature signal
Using an ohmmeter, measure the resistance between contacts 3 and 4. Nominal value: ∞ Ohm.
The original can be read on the resource HYUNDAIBOOK.ru