Inspection Procedures

1. Check connectors for poor connection, misplaced, bent, loose or corroded terminals.

Are both connectors good? 

Yes: Go to next step.

No: Repair or replace it.

1. Turn ignition switch to OFF and disconnect HO2S connector.
2. Measure resistance between the terminals 3 and 4 of HO2S connector.

Fig 1: Measuring Resistance Between Terminals 3 & 4 Of HO2S Connector

Courtesy of HYUNDAI MOTOR CO.

• 3 ~ 4 Ω at between 18°C and 28°C (64°F ~ 82°F) 

Is resistance within specification? 

Yes: Go to next step.

No: Replace HO2S.

1. Turn ignition switch to OFF and disconnect HO2S connector.
2. Turn ignition switch to ON.
3. Measure voltage between the terminal 3 of HO2S harness connector and chassis ground.

Fig 2: Measuring Voltage Between Terminal 3 Of HO2S Harness Connector & Chassis Ground

Courtesy of HYUNDAI MOTOR CO.

• Specification: approximately B+ 

Is voltage within specification? 

Yes: Go to next step.

No: Repair open or short to chassis ground in harness.

1. Turn ignition switch to OFF.
2. Disconnect ECM and HO2S connectors.
3. Turn ignition switch to ON.
4. Measure voltage between the terminal 4 of HO2S harness connector and chassis ground.

Fig 3: Measuring Voltage Between Terminal 4 Of HO2S Harness Connector & Chassis Ground

Courtesy of HYUNDAI MOTOR CO.

• Specification: below 0.5V 

Is voltage within specification? 

Yes: Go to next step.

No: Repair short to power in harness.

1. Turn ignition switch to OFF.
2. Measure resistance between the terminal 4 of HO2S harness connector and 13 of ECM harness connector C133-2.

Fig 4: Checking HO2S Harness

Courtesy of HYUNDAI MOTOR CO.

• Specification: below 1Ω 

Does resistance indicate continuity? 

Yes: Proceed with ECM PROBLEM PROCEDURE .

No: Repair open in harness.