Possible Causes
WARNING: This page is about a different car, the 2003 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when AF+ is 0.5 volt or less or 4.5 volts or more for 5 seconds or more and/or when output voltage remains fixed at 0.1 volt or less or 0.8 volt or more for 5 seconds or more. Possible causes are:
- A/F sensor circuit is open or shorted.
- Defective A/F sensor.
- Defective A/F sensor heater.
- Defective EFI main relay.