P0043
HO2S Heater Control Circuit Low Bank 1 Sensor 3
P0043 is an OBD-II diagnostic trouble code meaning: HO2S Heater Control Circuit Low Bank 1 Sensor 3. Common causes: broken wire in the sensor heater circuit, short circuit to ground. Estimated repair cost: $11–89.
Symptoms
- Check Engine Light Illuminates
- Increased fuel consumption
- Unstable engine idling
- Reduced engine power
- Black smoke from the exhaust pipe
- Smell of unburned fuel
Causes
- Broken wire in the sensor heater circuit
- Short circuit to ground
- Faulty oxygen sensor heater relay
- Failure of the sensor heating element
- Poor contact in the sensor connector
- PCM malfunction (rare)
How to Fix
- Check fuses and relays for the sensor heating system
- Inspect wiring for damage and corrosion
- Measure the resistance of the sensor heating element
- Check the supply voltage at the sensor connector
- Test the circuit for short circuit and open circuit
- If necessary, replace the oxygen sensor
- Clear error memory and test drive
Related codes
Error P0043 by Vehicle Brand
FAQ
What does the P0043 code mean?
P0043 is an OBD-II diagnostic trouble code that indicates: HO2S Heater Control Circuit Low Bank 1 Sensor 3
What causes a P0043 error code?
The most common causes of P0043 include: Broken wire in the sensor heater circuit; Short circuit to ground; Faulty oxygen sensor heater relay; Failure of the sensor heating element.
How do I fix a P0043 diagnostic trouble code?
To fix P0043: Check fuses and relays for the sensor heating system. Inspect wiring for damage and corrosion. Measure the resistance of the sensor heating element. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0043?
Yes, but get it checked soon
How much does it cost to fix P0043?
The estimated repair cost for P0043 is $11–89. Actual cost depends on your vehicle, location, and labor rates.
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