Circuit Description

Heated oxygen sensor monitors exhaust gas oxygen content and delivers input signals to ECM. Heated oxygen sensor is located on exhaust pipe, behind catalytic converter. Heated oxygen sensor may also be referred to as oxygen sensor (bank No. 1 sensor No. 2). ECM uses input signals to determine fuel injection system operation. DTC is set when heated oxygen sensor heater current draw exceeds 2.35 amps or is .2 amp or less when heater operates. If DTC P0141 exists, ECM will operate in fail-safe mode and turn off heater for heated oxygen sensor. Possible causes are:

• Heated oxygen sensor circuit is open or shorted.
• Defective heated oxygen sensor.
• Defective ECM.