P0043 — HO2S Heater Control Circuit Low Bank 1 Sensor 3

What Does P0043 Mean?

P0043 is a diagnostic trouble code indicating: HO2S Heater Control Circuit Low Bank 1 Sensor 3. This code relates to the fuel and air metering system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P0043

⚠️ Check Engine Light (MIL) illuminated
⚠️ HO2S Heater reading at zero or minimum value
⚠️ Related system not functioning or in fail-safe mode
⚠️ Poor fuel economy

Common Causes

🔍 Open or broken wire in HO2S Heater circuit
🔍 Poor ground connection at HO2S Heater
🔍 Faulty HO2S Heater with no output signal
🔍 Disconnected or loose HO2S Heater connector
🔍 Blown fuse in related circuit

Frequently Asked Questions

What does P0043 mean?

P0043 indicates: HO2S Heater Control Circuit Low Bank 1 Sensor 3. The vehicle's computer has detected that the HO2S Heater is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P0043?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P0043 for extended periods may cause additional problems.

How much does it cost to fix P0043?

Repair costs for P0043 typically range from $20 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Repair broken wire or restore ground in HO2S Heater circuit
🔧 Clean and secure HO2S Heater connector and ground points
🔧 Replace failed HO2S Heater

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P0043: HO2S Heater Control Circuit Low Bank 1 Sensor 3