Diesel Data: Automotive Repair

Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection

INTAKE AIR TEMPERATURE (EAT) SENSOR

The intake air temperature sensor (IAT Sensor), located in the intake air hose, is a thermistor sensor for detecting the intake air temperature. According to the intake air temperature information from the sensor, the ECM provides necessary fuel injection amount control.

Circuit Diagram:






Troubleshooting Procedures:






TROUBLESHOOTING HINTS
The MIL is ON or the DTC is displayed on the HI-SCAN under the following condition;
1. When the intake air temperature is detected as below -40 °C or higher than 120 °C
2. Input from intake air temperature sensor is below 0.1 V or above 4.8 V when engine is in a full warm-up condition.

Using Hi-scan:






Harness Inspection Procedure:






SENSOR INSPECTION
1. Use the multimeter, measure the sensor resistance.




2. Measure the resistance between the IAT sensor terminal 1 and 2.
3. If the resistance deviates from the standard value, replace the intake air temperature sensor assembly.