Circuit Description
WARNING: This page is about a different car, the 2002 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
Heated oxygen sensors located on each exhaust pipe behind catalytic converter monitor exhaust gas oxygen content and deliver input signals to ECM. Heated oxygen sensor on driver's side exhaust pipe may be referred to as bank No. 1 sensor No. 2 and heated oxygen sensor on passenger's side exhaust pipe may be referred to as bank No. 2 sensor No. 2. ECM uses input signal to determine fuel injection system operation. DTC is set when heated oxygen sensor heater current draw exceeds 2 amps or heated oxygen sensor heater current draw is .2 amp or less when heater operates. If DTC P0141 or DTC P0161 exists, ECM will operate in fail-safe mode in which heater on oxygen sensor will be turned off. Possible causes are:
- Heated oxygen sensor circuit is open or shorted.
- Defective heated oxygen sensor.
- Defective ECM.