P0043

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

1. Check fuses and relays for the sensor heating system
2. Inspect wiring for damage and corrosion
3. Measure the resistance of the sensor heating element
4. Check the supply voltage at the sensor connector
5. Test the circuit for short circuit and open circuit
6. If necessary, replace the oxygen sensor
7. Clear error memory and test drive

Related codes

Error P0043 by Vehicle Brand