Check The Signal Waveform Of HO2S

IG "OFF". Connect HO2S connector.
Connect probe to HO2S to measure signal waveform using oscilloscope function. Start engine.
After warming-up, monitor signal waveform of HO2S with GDS.

Fig 1: Screen Display - Normal Waveforms Of Front HO2S (Upper) And Rear HO2S (Lower) (Chassis Ground Used)
Courtesy of HYUNDAI MOTOR AMERICA

Fig 2: Screen Display - Normal Waveforms Of Front HO2S (Upper) And Rear HO2S (Lower) (Sensor Ground Used)
Courtesy of HYUNDAI MOTOR AMERICA
Is the sensor switching properly?
YES
- Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.