Signal Waveform And Data

Fig 1: Signal Waveforms Of Front HO2S And Heater At Idle

Courtesy of KIA MOTORS AMERICA, INC.

Fig 2: Signal Waveforms Of Rear HO2S And Heater At Idle

Courtesy of KIA MOTORS AMERICA, INC.

The HO2S requires a minimum temperature to provide a closed loop fuel control system. So the HO2S contains a heater element to reduce its warm-up time and ensure its performance during all driving conditions. The ECM controls this heater element by duty cycle. The main relay supplies voltage to the heater and the ECM provides a ground circuit for activating the heater.