Inspection Procedures

WARNING: This page is about a different car, the 2004 Hyundai Tiburon. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HO2S AND ECM CONNECTORS
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 HO2S
CHECK HO2S HEATER RESISTANCE
1. 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.
CHECK POWER TO HO2S HEATER
1. Turn ignition switch to ON.
2. 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 ground in harness.
CHECK THE SIGNAL WAVEFORM OF HO2S
1. Warm up engine to normal operating temperature.
2. Using Hi-Scan (Pro), monitor the signal.
Does the HO2S signal switch from lean to rich or from rich to lean?

Yes: Proceed with ECM PROBLEM PROCEDURE .

No: Replace HO2S