P0143

P0143 HO2S3

Description




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

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

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

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

Step 1-2:

Step 2 (Continued):

Diagnostic Procedure

Step 1-5:

Step 5 (Continued)-8: