P1155 Air/Fuel Sensor Heater Circuit (Bank 2 Sensor 1)
What does P1155 mean on a Toyota?
P1155 — Air/Fuel Sensor Heater Circuit (Bank 2 Sensor 1). This Toyota-enhanced code applies to Camry V6, Highlander, Sienna, Tundra, Sequoia.
Common causes of P1155
- Open heater filament inside the sensor (dominant failure, worse in winter)
- Blown A/F heater fuse
- Oxidized sensor connector
- Open heater control circuit
- Failed heater relay
How to fix P1155
- Test heater element resistance — open means a new sensor
- Check the A/F heater fuse
- Inspect the connector for oxidation
- Verify heater command with a scanner on cold start
- Replace the sensor; heater faults rarely heal