P1646moderate severityPowertrain
Front Heated O2 Sensor Bank 1 Fault
on 2010 Volvo XC70 3.2L I6 · FWD
What this code means
The ECM detected a fault in the front (upstream) heated oxygen sensor on Bank 1. The sensor signal or heater circuit is not operating within specification.
Symptoms
- Check Engine Light
- Poor fuel economy
- Rough idle
- Failed emissions test
Common causes
- Faulty O2 sensor Bank 1
- O2 sensor heater failure
- Exhaust leak near sensor
- Wiring damage to sensor
- Connector corrosion
Diagnostic steps
- Test O2 sensor signal voltage and switching rate
- Test heater circuit resistance
- Check for exhaust leaks near sensor
- Inspect wiring and connector
- Compare Bank 1 vs Bank 2 sensor performance
Repair notes
Replace the front heated O2 sensor on Bank 1.
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