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Home >> Chevrolet >> 1999 >> Forward Control P12 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes - DTC P0135-P0204 >> DTC P0141 >> DTC P0141: Ho2S Heater Circuit-Sensor 2 (1.9L SATURN) >> Circuit Description

Circuit Description

HO2S 2 is mounted behind the catalytic converter. This sensor is used to determine the oxygen storage capability of the catalytic converter. Oxygen storage capability is used as a measurement of converter condition and its ability to perform its function. Sensor heater is controlled by PCM.

PCM diagnoses the heater and its related circuit by monitoring the electrical current. DTC P0141 will set if the current range does not fall within the calibrated limits. DTC will also set if current feedback is less than 0.5 amp or greater than 2.4 amps for longer than 50 seconds when catalyst temperature is less than 1427°F (775°C).

NOTE: If DTC P0405 (EGR) and P0443 (EVAP CCP) are present, replace faulty EGR fuse located in underhood fuse block.