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P0054 – What Does It Mean and How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


P0054 is an OBD-II Code that refers to HO2S Heater Resistance (Bank 1, Sensor 2)


A P0054 code is a generic diagnostic trouble code that occurs when the PCM/ECM detects a signal voltage input from the Heated Oxygen Sensor (HO2S) that the resistance is out of range with engine bank 1 (side of engine with cylinder #1) on the sensor downstream or behind the catalytic converter

When this happens a P0054code will be stored and the indicator lamp for this fault may be illuminated.


Common causes for this code include:

  • The MAF sensor might be malfunctioning
  • The Oxygen Sensor cables or connectors are in poor condition
  • The O2 Sensor may be faulty
  • The connection of the fuse or the fuse itself has been damaged.
  • Broken throttle control switch.


The symptoms of a P0054 code are:

  • The Check Engine Light will come on
  • Due to a lean cold start condition, the engine does not start up on time
  • Fuel efficiency is diminished
  • The smoke from the exhaust is black, due to a rich cold start situation
  • Other associated diagnostic trouble codes may also be stored


To diagnose a P0054 DTC code, a technician would:

  1. Scan for codes in the ECM and look at the freeze frame data for failure.
  2. Start by checking the resistance across the wires of the HO2S, which should be about 8 ohms with a range of 7-9 ohms. 
  3. If the resistance is outside of the acceptable range, it’s likely that the sensor has failed and must be replaced.
  4. If the resistance is acceptable, the problem may be in the wiring, which must be meticulously examined for a disconnected sensor, an incorrect connection, or faulty wiring caused by the exhaust system’s proximity.

Common mistakes

The following are some of the most common mistakes that a technician may make when diagnosing a P0054 code:

  • Not thoroughly inspecting the air intake system for leaks.
  • Not properly checking the mass air flow sensor.
  • Not cleaning the MAF sensor.
  • Not checking the fuel pressure regulator.
  • Not properly testing the oxygen sensors.
  • Failing to properly diagnose the PCM.

How serious is this?

A P0054 code is considered to be a serious code. If the code is not properly diagnosed and fixed, it can result in drivability problems and even engine damage.

What repairs can fix the code?

repair manualsrepair manuals

The following are solutions that may fix this problem:

  • Repair or replace any faulty parts such as the oxygen sensor, wiring, connectors, fuse, and the throttle control switch.
  • Check for leaks in the vacuum system.
  • Inspect and clean the MAF sensor.
  • Check and adjust the fuel pressure if necessary.
  • Replace the catalytic converter if it is damaged or clogged.
  • Reprogram or replace the PCM/ECM (Rare)

Related codes

A P0054 is related to and may be accompanied by the following codes:

P0050 – HO2S Heater Resistance (Bank 1, Sensor 1)

P0051 – HO2S Heater Resistance (Bank 2, Sensor 1)

P0052 – HO2S Heater Resistance (Bank 1, Sensor 2)

P0053 – HO2S Heater Resistance ( Bank 2, Sensor)


In conclusion, the P0054 code is a diagnostic trouble code that refers to a problem with the HO2S Heater Resistance (Bank 1, Sensor 2) on the engine. The code is usually caused by a faulty oxygen sensor, wiring, connector, fuse, or the throttle control switch. The code is considered to be a serious one and if not properly fixed, can lead to drivability problems and even engine damage. There are several possible repairs that can be made to fix the code, but the most common one is to replace the faulty oxygen sensor.