Possible Causes
WARNING: This page is about a different car, the 2003 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
These DTCs uses two-trip detection logic. DTC is set when A/F sensor (Bank 1 & 2 Sensor 1) heater current draw exceeds 8 amps or is 0.25 amp or less when heater operates. Possible causes are:
- A/F sensor (Bank 1 & 2 Sensor 1) circuit is open or shorted.
- Defective A/F sensor (Bank 1 & 2 Sensor 1).
- Defective A/F heater relay.
- Defective ECM.