Signal Waveform & Data
Fig 1: Display - Signal Waveforms Of Front HO2S (Upper) And Heater (Lower) At Idle - Chassis Ground Used
Fig 2: Display - Signal Waveforms Of Front HO2S (Upper) And Heater (Lower) At Idle - Sensor Ground Used
Fig 3: Display - Signal Waveforms Of Rear HO2S (Upper) And Heater (Lower) At Idle - Chassis Ground Used
Fig 4: Display - Signal Waveforms Of Rear HO2S (Upper) And Heater (Lower) At Idle - Sensor Ground Used
The output voltage of front HO2S changes continuously according to air/fuel ratio. The PCM controls fuel amount based on this value. Preheating is necessary for HO2S normal operation. A heater unit is installed in each HO2S. The PCM can control air/fuel ratio with the output signal of HO2S simultaneous with engine run by reducing preheating time. The HO2S power source is the engine control relay. PCM operates heater by ground control.