Component Inspection

1. Visually/physically inspect following items:
   • Inspect the front HO2S for Contaminated, deteriorated or aged Front HO2S
   • If contamination is evident on the HO2S, replace contaminated sensor
2. Is the HO2S visually / physically O.K ?

YES 

• Go to  2 "Check Performance of HO2S" as below

NO 

• Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and go to "VERIFICATION OF VEHICLE REPAIR "

1. Connect scantool & Engine "ON"
2. Warm-up the engine to normal engine temperature.
3. Monitor signal waveform of HO2S with scantool

   Specification : Voltage will vary from 0.1 to 0.9 V

   Fig 1: Identifying Signal Waveform

   Courtesy of HYUNDAI MOTOR CO.
4. Is the sensor signal 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, replace HO2S and go to "VERIFICATION OF VEHICLE REPAIR " procedure.