P0043
HO2S Heater Control Circuit Low Bank 1 Sensor 3
Generic code
Fuel and Air Metering
Medium severity
Moderate repair
Free on OBD DashX
Want real-world data on P0043?
See which problems come with P0043, how often it shows up in other vehicles, and how to fix it — step by step.
- Real-world fix data
- How often it happens
- Step-by-step repairs
What P0043 means
- The fault code P0043 indicates a low voltage condition in the heated oxygen sensor (HO2S) heater control circuit for bank 1, sensor 3. This can result in improper heating of the oxygen sensor and affect its ability to accurately measure the oxygen content in the exhaust gases.
Possible symptoms
- Check Engine Light illuminated
- Poor engine performance
- Decreased fuel efficiency
- Failed emission test
- Possible rough idling or stalling
Possible causes
- Faulty heated oxygen sensor (HO2S)
- Open or short circuit in the HO2S heater control circuit
- Faulty engine control module (ECM)
Related parts
- Heated Oxygen Sensor: This is one of the parts that fails very commonly. It measures the amount of oxygen to ensure proper combustion. Problems in the Oxygen Sensor lead to poor fuel economy
Possible solutions
- Test and replace the faulty heated oxygen sensor (HO2S), if necessary
- Inspect and repair any open or short circuits in the HO2S heater control circuit
- Test and replace the engine control module (ECM) if it is determined to be faulty
Free on OBD DashX
P0043 on OBD DashX
Real-world causes, how often this code shows up, and the fix — step by step.
Open P0043 No sign-up needed · available in 10 languagesScan your own car
Read and clear fault codes, live data and service resets with the CaRPM app.