Atmospheric sensor is installed in ECM and senses atmospheric pressure where the vehicle is. Based on signal of atmospheric sensor, air density is calculated. And atmospheric sensor is used to detect mass air flow with MAFS, IATS. This sensor is required to perform 1) fuel injection quantity correction in high altitude and 2) EGR control. Atmospheric pressure is fixed at 1000hpa when atmospheric sensor fails.

P0108 is set when the voltage above 4.85V - maximum output voltage of Barometric pressure sensor - is detected for more than 0.8 sec. This code is due to fee failure of the sensor inside of ECM.