P1166low severityPowertrain
HO2S Bank 1 Sensor 1 Heater Circuit Fault
on 2007 Acura MDX 3.7L V6 · AWD
What this code means
The heater circuit in the upstream O2 sensor has a malfunction.
Symptoms
- CEL
- Poor cold-start economy
- Extended warm-up
- Increased emissions
Common causes
- Failed heater element
- Blown fuse
- Open/short wiring
- Corroded connector
Diagnostic steps
- Test heater resistance
- Check fuse
- Inspect wiring
- Test PCM relay
Repair notes
Replace O2 sensor or repair heater circuit.
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