Circuit Description
WARNING: This page is about a different car, the 2000 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
Air/Fuel (A/F) sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. ECM uses input signal to control air/fuel ratio. A/F sensor includes a heater. DTC is set when A/F sensor output does not change with engine speed at 1500 RPM or more, vehicle speed at 25-62 MPH and throttle valve not fully closed for at least 2 minutes. Possible causes are:
- A/F sensor circuit is open or shorted.
- Defective A/F sensor (bank No. 1 or 2, sensor No. 1).
- Air induction system malfunction.
- Improper fuel pressure.
- Defective injector.
- Exhaust system leak.
- Running vehicle out of fuel.
- Defective ECM.