Control Circuit Inspection

■ Check voltage 

1. IG "OFF" & Disconnect HO2S (B1/S1) connector.
2. IG "ON".
3. Measure voltage between control terminal of HO2S(B1/S1) heater harness connector and chassis ground.

   Specification:  Approx. 3.5V

   Fig 1: Measuring Voltage Between Control Terminal Of HO2S (B1/S1) Heater Harness Connector And Chassis Ground

   Courtesy of HYUNDAI MOTOR AMERICA
4. Is the measured voltage within specification?

   YES 

   • Go to "Component Inspection " procedure below.

   NO 

   • Repair short to battery in HO2S (B1/S1) Heater control circuit and go to "Verification of Vehicle Repair " procedure.