4. Check Power To HO2S Heater

1. Turn ignition switch to OFF position and disconnect HO2S connector.
2. Turn ignition switch to ON position.
3. Measure voltage between terminal 5 of the HO2S harness connector and chassis ground.
   Fig 1: Measuring HO2S Heater Supply Voltage

   Courtesy of HYUNDAI MOTOR CO.
   • Specification : approximately B+ 

Is voltage within specification? 

Yes: Go to next step.

No: Repair open or short to ground in harness.