P0155 O2 Sensor Heater Circuit (Bank 2, Sensor 1)
What does P0155 mean?
P0155 — O2 Sensor Heater Circuit (Bank 2, Sensor 1) (bank 2). This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects o2 sensor heater circuit (bank 2, sensor 1) on bank 2. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0155
- Blown O2 sensor heater fuse
- Open or shorted bank 2 heater wiring
- Failed upstream sensor heater
- Corroded connector
- Faulty PCM heater driver
How to fix P0155
- Check the bank 2 sensor heater fuse
- Measure the heater circuit resistance at the sensor
- Verify power and ground at the connector
- Replace the sensor if its heater is damaged
- Repair wiring and confirm the heater duty cycle returns