Nissan Altima 2007-2012 Service Manual: P0143 HO2S3

Description

The heated oxygen sensor 3, after HC adsorption catalyst (Under floor), monitors the oxygen level in the exhaust gas on each bank.

This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions.

Under normal conditions the heated oxygen sensor 3 is not used for engine control operation.

DTC Logic


DTC Logic

DTC DETECTION LOGIC

The heated oxygen sensor 3 has a much longer switching time between rich and lean than the air fuel ratio (A/F) sensor 1. The oxygen storage capacity of the three way catalyst (manifold) causes the longer switching time. To judge the malfunctions of heated oxygen sensor 3, ECM monitors whether the minimum voltage of sensor is sufficiently low during the various driving condition such as fuel-cut.


DTC CONFIRMATION PROCEDURE


DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and warm it up to the normal operating temperature.

2. Repeat the following procedure 3 times.

- Drive vehicle at a speed of 80 km/h (50 MPH) or more for at least 3 consecutive minutes.

CAUTION: Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.

NOTE:

    P0139 HO2S2
    Description The heated oxygen sensor 2, after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Even if switching characteristics of the air fuel ratio (A/ ...

    P0144 HO2S3
    Description The heated oxygen sensor 3, after HC adsorption catalyst (Under floor), monitors the oxygen level in the exhaust gas on each bank. This sensor is made of ceramic zirconia. The zircon ...

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