Circuit Description
WARNING: This page is about a different car, the 2002 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
Heated Air/Fuel (A/F) sensor monitors exhaust gas oxygen content and delivers input signals to ECM. Heated A/F sensor is located on exhaust pipe in front of catalytic converter. A/F sensor may also be referred to as A/F sensor (bank No. 1 sensor No. 1) or A/F ratio sensor. ECM uses input signals to determine fuel injection system operation. DTC is set when A/F sensor heater current draw exceeds 8 amps or is .25 amp or less when heater operates. Possible causes are:
- A/F sensor circuit is open or shorted.
- Defective A/F sensor.
- Defective ECM.