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 " procedure.
  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 scantool.
  
  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
  - Go to "Check the fuel filter of fuel pump " 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 the fuel filter of fuel pump
1. Ignition "OFF" and disconnect the fuel pump connector.
2. Start the engine and wait until fuel in fuel line is exhausted. After the engine stalls, Ignition "OFF"
3. Remove the fuel pump assembly.
4. Check the fuel filter for clogging by dust, a foreign substance.
5. Is the fuel filter OK?
  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 fuel filter and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.