P0043 Code - HO2S Heater Control Circuit Low Bank 1 Sensor 3
Quick Answer
Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 harness is open shorted, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0043 indicates HO2S Heater Control Circuit Low Bank 1 Sensor 3.
- Common causes
- Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 harness is open shorted, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit poor electrical connection.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Code P0043 Description
In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The ECM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The ECM controls the heater element circuit by allowing current flow to ground.
The ECM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.
What are the Possible Causes of the DTC P0043?
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 harness is open shorted
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 circuit poor electrical connection
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 3 fuse
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0043?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0043 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P0043 Audi — HO2S Heater Control Circuit Low Bank 1 Sensor 3
- P0043 Infiniti — Heated Oxygen Sensor 3 Heater Control Circuit Low
- P0043 Lexus — HO2S Heater Control Circuit Low Bank 1 Sensor 3
- P0043 Mazda — HO2S Heater Control Circuit Low 12
- P0043 Mitsubishi — HO2S Heater Control Circuit Low Bank 1 Sensor 3
- P0043 Nissan — Heated Oxygen Sensor 3 Heater Control Circuit Low
- P0043 Subaru — HO2S13 Heater Control Circuit Low
- P0043 Toyota — HO2S Heater Control Circuit Low Bank 1 Sensor 3
- P0043 Volkswagen — HO2S Heater Control Circuit Low Bank 1 Sensor 3
Frequently Asked Questions about P0043 Code
No Frequently Asked Questions about P0043 Code found.
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