P0056low severityPowertrain
HO2S Heater Control Circuit Bank 2 Sensor 2
on 2010 Mazda MX-5 Miata 2.0L I4 · RWD
What this code means
Malfunction in the heater circuit for the downstream O2 sensor on Bank 2.
Symptoms
- Check Engine Light
- Failed emissions
- Poor catalyst monitoring
Common causes
- Faulty sensor heater
- Blown fuse
- Wiring issue
Diagnostic steps
- Check fuse
- Test heater resistance
- Inspect wiring
Repair notes
Replace O2 sensor or repair wiring.
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