Component Inspection

Check the condition of HO2S
1. Check HO2S for poor connection or loose terminal.
2. Check if HO2S is securely installed.
3. Is the conditions of HO2S normal?
  YES
  - Go to "Check the signal waveform of HO2S " Check the fuel filter of fuel pump
  NO
  - Repair it and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
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 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
4. Is the sensor switching properly?
  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.