P0155low severityPowertrain
O2 Sensor Heater Circuit Bank 2 Sensor 1
on 2004 Subaru Legacy 3.0L H6 · AWD
What this code means
Malfunction in the upstream O2 sensor heater on Bank 2.
Symptoms
- Check Engine Light
- Extended warmup emissions
Common causes
- Faulty heater
- Blown fuse
- Wiring issue
Diagnostic steps
- Check fuse
- Test heater resistance
- Inspect wiring
Repair notes
Replace O2 sensor.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1