Heated Oxygen Sensor: Spectra
- Disconnect front or rear HO2S 4-pin harness connector. At front or rear HO2S side connector measure resistance between terminals No. 1 and 3. See Fig 1. HO2S heater resistance should be between 2-4 ohms at 68°F (20°C). If HO2S is not as specified, replace HO2S.
- Connect HO2S connector. Start and run engine at normal operating temperature for at least 10 minutes. Using scan tool, lab scope or voltmeter, monitor appropriate HO2S signal. If using voltmeter or lab scope, connect positive lead to front HO2S harness connector terminal No. 4 (Green/Brown wire) or to rear HO2S harness connector terminal No. 4 (Green/White wire). Connect negative lead to ground. HO2S signal should switch from lean to rich, or rich to lean, at least 3 times every 10 seconds. Front HO2S signal should switch between 0-1 volt. Rear HO2S signal should switch between .6-.8 volt. If HO2S is not as specified, replace HO2S.
Courtesy of KIA MOTORS AMERICA, INC.