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. Disconnect ECM connector.
2. Measure resistance between the terminal 4 of HO2S harness connector and chassis ground.

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

Courtesy of HYUNDAI MOTOR CO.

• Specification: infinite 

Does resistance indicate open? 

Yes: Proceed with ECM PROBLEM PROCEDURE .

No: Repair short to chassis ground in harness.