Signal Waveform & Data

Fig 1: Normal Data Of HO2S Heaters At Idle

Courtesy of HYUNDAI MOTOR AMERICA

Fig 2: Normal Data Of HO2S Heaters At Open Condition In HO2S (B2/S1) Circuit

Courtesy of HYUNDAI MOTOR AMERICA

Fig 3: Signal Waveforms Of Front Upper HO2S And Lower Heater At Idle (Chassis Ground Used)

Courtesy of HYUNDAI MOTOR AMERICA

Fig 4: Signal Waveforms Of Front Upper HO2S And Lower Heater At Idle (Sensor Ground Used)

Courtesy of HYUNDAI MOTOR AMERICA

Fig 5: Signal Waveforms Of Rear Upper HO2S And Lower Heater At Idle (Chassis Ground Used)

Courtesy of HYUNDAI MOTOR AMERICA

Fig 6: Signal Waveforms Of Rear Upper HO2S And Lower Heater At Idle (Sensor Ground Used)

Courtesy of HYUNDAI MOTOR AMERICA

The output voltage of front HO2S is changed continuously according to air/fuel ratio, PCM controls fuel amount based on this value. Preheating is necessary for HO2S normal operation. Therefore heater unit is installed in HO2S, PCM can control air/fuel ratio with the output signal of HO2S simultaneous with engine run by reducing preheating time. PCM controls heater with duty cycle. HO2S' power source is main relay and PCM operates heater by ground control.