What is the P0055 fault number? What is the failure description of the HO2S Heating Resistor (Bank 1 Sensor 3)? How do I fix the P0055 fault code What are the causes and symptoms of the P0055 error code?

What is the P0055 fault code? What does it stand for?

When the powertrain control module, PCM detects an issue with resistance in the third oxygen sensor heater circuit of the engine’s first row, a code P0055 will be triggered. Bank 1 refers to the engine’s side that contains the 1st-cylinder. “Sensor 3,” refers to downstream oxygen sensor which comes after the catalytic conversion.

An oxygen sensor has a zirconium dioxide sensing element that is enclosed in a steel case. This element can sense oxygen and generate small amounts of electrical voltage.

The PCM uses data from oxygen sensors for measuring the oxygen content of the exhaust. These data allow the PCM to fine-tune the air fuel mixture, adjust fuel delivery, and set ignition timing.

In order to give accurate and sensitive information to a PCM, oxygen sensors need to reach a certain temperature. Many oxygen sensors come with a heating component. A heater circuit is usually composed of a battery voltage wire (minimum 22.6 volts) as well as a system ground. Based on information received from the engine coolant temperatures, the PCM superheats O2 sensor heaters with the help of relays and/orfuses. The current to the O2 sensors heater circuit is cut off when the engine reaches normal operating temperatures.

When it detects resistance in the oxygen sensor heater circuit, the PCM assigns fault code P0055.

 

What causes the P0055 Fault code?

This code can be caused by the most common cause, the destruction of an oxygen sensor heater.

  • – Connectors and cables that have been damaged, melted or are no longer in use
  • – Defective oxygen sensor (Bank 1 Sensor 3)
  • – The heating component is blown to a fuse
  • – Defective engine control relay
  • – Defective PCM (rarely)

 

What are the symptoms for P0055 fault code?

  • – Illumination for check engine light
  • – Engine that runs cold and hard.
  • – Increased fuel consumption
  • Due to the rich mixture, black smoke is produced from exhaust.
  • – Low engine performance
  • – Other fault codes can be set

 

How to Fix the P0055 Fault Code

  • – Replacing a defective oxygen sensor (Bank 1 Sense 3)
  • Repairing a broken or melted wire in the heater circuit
  • – Connector replacement and check
  • – Replacing engine control module/fuse

 

How Serious Is the P0055 Fault Coding?

This code should not cause any driving problems. However, a fault in a heater circuit could cause an engine control module connection to be burned and cause a short-circuit. It is important to fix the problem as soon as possible as it will cost more to replace the engine control module.