Inspection Procedures

1. Check HO2S and ECM 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. Remove HO2S.
2. Thoroughly check HO2S for contamination, deterioration or damage.

Is HO2S contaminated, deteriorated or damaged? 

Yes: Proceed with ECM PROBLEM PROCEDURE .

Yes: Clean or replace HO2S.