Control Circuit Inspection

Check for open in control harness.
1. Ignition "OFF".
2. Disconnect ECM connectors.
3. Measure resistance between terminals 4 of the HO2S heater harness connector and 19 of the ECM harness connector.
  Specification: Approx. 0Ω
  
  Fig 1: Measuring Resistance Between HO2S Heater Harness Connector And ECM Harness Connector
  Courtesy of HYUNDAI MOTOR CO.
4. Is resistance within the specification?
  YES : --> Go to next step as below.
  
  NO : --> Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to ground in control circuit.
1. Measure resistance between terminal 4 of the HO2S heater harness connector and chassis ground.
  Specification: infinite
  
  Fig 2: Measuring Resistance Between HO2S Heater Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
2. Is resistance within the specification?
  YES : --> Go to "COMPONENT INSPECTION " procedure.
  
  NO : --> Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to power in control circuit.
1. Ignition "ON" & Engine "OFF"
2. Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground
  Specification: Approx. 0V
  
  Fig 3: Measuring Voltage Between HO2S Heater Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
3. Is voltage within the specification?
  YES : --> Go to "COMPONENT INSPECTION " procedure.
  
  NO : --> Repair open or short to ground in control circuit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.