Component Inspection

Check the Signal waveform of HO2S
1. IG "OFF" and connect HO2S connector.
2. Engine start.
3. After warming-up, monitor signal waveform of HO2S with GDS.
  
  Fig 1: Checking Oxygen Sensor Signal Waveform
  Courtesy of HYUNDAI MOTOR AMERICA
  
  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
  
  Normal waveforms of upstream HO2S(the upper) and downstream HO2S(the lower) (chassis ground used), refer to Fig 2.
  
  Normal waveforms of upstream HO2S(the upper) and downstream HO2S(the lower) (sensor ground used), refer to Fig 3.
4. Is the sensor switching properly?
  YES
  - Go to " Check HO2S" as below.
  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. IG "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.