Kia Carnival (2009+). Instruction — part 251

2009 > G 2.7 DOHC >

INSPECTION

FUNCTION AND OPERATION PRICIPLE

Heated Oxygen Sensor (HO2S) consists of zirconium and alumina and is installed on upstream and downstream of the
Manifold Catalyst Converter (MCC). After it compares oxygen consistency of the atmosphere with the exhaust gas, it
transfers the oxygen consistency of the exhaust gas to the PCM. When A/F ratio is rich or lean, it generates
approximately 1V or 0V respectively. In order that this sensor normally operates, the temperature of the sensor tip is
higher than 370°C (698°F). So it has a heater which is controlled by the PCM duty signal. When the exhaust gas
temperature is lower than the specified value, the heater warms the sensor tip.

SPECIFICATION

A/F Ratio

Output Voltage (V)

RICH

0.80 ~ 0.92

LEAN

0.1

Item

Specification

Heater Resistance (!)

3.0 ~ 4.0! at 21°C (69.8°F)

WAVEFORM

CIRCUIT DIAGRAM

COMPONENT INSPECTION

1. Check signal waveform of HO2S using a scantool.

Specification: Refer to "waveform".

2. Disconnet the HO2S connector.

3. Measure resistance between HO2S heater terminals 3 and 4.

4. Check that the resistance is within the specification.

Specification: Refer to SPECIFICATION.