Component Inspection

Check the signal waveform of HO2S
1. Ignition "OFF" and connect HO2S connector.
2. Start engine.
3. After warming-up, monitor signal waveform of HO2S with GDS.
  
  Fig 1: Checking HO2S Signal Waveform
  Courtesy of HYUNDAI MOTOR CO.
  
  Fig 2: Display - Normal Waveforms Of Upstream HO2S (Upper) And Downstream HO2S (Lower) - Chassis Ground Used
  Courtesy of HYUNDAI MOTOR AMERICA
  
  Fig 3: Display - Normal Waveforms Of Upstream HO2S (Upper) And Downstream HO2S (Lower) - Sensor Ground Used
  Courtesy of HYUNDAI MOTOR AMERICA
4. Is the sensor switching properly?
  YES
  - Go to "Check HO2S " 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.
Check HO2S
1. Ignition "OFF" and disconnect HO2S connector.
2. Check that the HO2S is securely installed.
3. Check the HO2S for contamination or damage
4. Is the sensor normal?
  YES
  - Substitute with a known-good ECM and check for proper operation. If the problem is corrected, replace ECM 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.