HO2S Heater Control Circuit Low Bank 1 Sensor 1
2007-2007 Mitsubishi Eclipse 2.4L I4
The 2007 Mitsubishi Eclipse is equipped with a 2.4L inline-4 engine. Below you'll find detailed p0031 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
The voltage in the Bank 1 Sensor 1 O2 heater circuit is lower than expected.
Symptoms
- Check Engine Light
- Extended warmup time
- Poor cold-start emissions
Common Causes
- Short to ground in heater circuit
- Faulty O2 sensor
- Corroded connector
Diagnostic Steps
- Test heater circuit voltage
- Check for shorts to ground
- Test sensor heater resistance
- Inspect connector
Repair Notes
Repair short or replace O2 sensor.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0031 on Other Vehicles
Mitsubishi 3000GT
1996-1996 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1997-1997 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1998-1998 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1999-1999 3.0L V6 Twin Turbo
Mitsubishi Colt JP
2002-2002 1.3L I4 4A90
Mitsubishi Colt JP
2002-2002 1.5L I4 4A91
Mitsubishi Colt JP
2003-2003 1.3L I4 4A90
Mitsubishi Colt JP
2003-2003 1.5L I4 4A91
Common Questions
What does code P0031 mean on a 2007-2007 Mitsubishi Eclipse?
P0031 stands for "HO2S Heater Control Circuit Low Bank 1 Sensor 1". The voltage in the Bank 1 Sensor 1 O2 heater circuit is lower than expected.
What are the symptoms of P0031 on a Mitsubishi Eclipse?
Common symptoms of P0031 include: Check Engine Light, Extended warmup time, Poor cold-start emissions.
What causes P0031 on a 2007-2007 Mitsubishi Eclipse?
Common causes of P0031 include: Short to ground in heater circuit, Faulty O2 sensor, Corroded connector.
Last updated: March 2026