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P0053 Code – What Does It Mean & 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.


OBD II code P0053 stands for “Heated O2 Sensor (HO2S) heater resistance (Group 1, Sensor 1)”. It indicates that the powertrain control module (PCM) has detected a problem in the upstream or pre-catalyzed oxygen sensor heater circuit. 

Bank 1″ means that the problem affects the engine block containing cylinder number 1, and “Sensor 1″ means that the problem involves the upstream oxygen sensor.


OBD- II code P0053 is defined as HO2S heater resistance. The purpose of the oxygen sensor is to measure the oxygen content in the fumes released during the ignition cycle. The oxygen sensor should be at a specific temperature for this information to be accurate. There is a heating wire inside the oxygen sensor to help the sensor achieve that temperature faster. When the PCM detects that the heating wire is not working, it will set the P0053 code. The O2 sensor gives the PCM information on the level of oxygen particles in the engine exhaust compared to the oxygen content of the encompassing air.

In the heated O2 sensor, the battery voltage is utilized to preheat the sensor under cold start conditions. Additionally, there is also a circuit dedicated to heating the sensor other than the  O2 sensor signal circuit. It ordinarily has a battery voltage (12.6 volt least) and may have a built-in fuse. Once the engine reaches normal operating temperature, the PCM will be programmed to stop supplying battery voltage to the O2 heater circuit and take appropriate action.


There are various factors that may potentially contribute to affecting fuel delivery to the engine. Some of them are listed beneath:

  • Heater oxygen sensor problem 
  • Oxygen sensor connector failure 
  • Sensor circuit wiring and harness problem 
  • Blown HO2 sensor fuse 
  • Optimal fuel pressure change 
  • Excessive vacuum and fuel leak exhaust 
  • ECM sensor due to circuit failure OR wiring is damaged


Possible symptoms of O2 sensor heater failure include the O2 sensor not giving correct readings as soon as possible. In this case, the ECU will enter a fail-safe mode until the system is repaired. 

  • Check Engine Light ON
  • Significant increase in fuel consumption 
  • Engine stalling and unable to start, while losing power and response 
  • Visible white or black smoke in the exhaust pipe 
  • Oil dilution caused by prolonged overload 
  • Irregular idling
  • Difficulty in starting the engine 
  • Carbon deposits affect spark plugs


 Usually, the check engine light on the dashboard lights up to indicate a problem. The mechanic uses the OBDII scanner to diagnose the problem to determine the fault code. 

  • The mechanic can then start by checking the resistance at both ends of the HO2S lead.
  • The resistance should be about 8 ohms in the range of 79 ohms. If the resistance is over the set limit, then the sensor is defective and ought to be replaced. If the resistance is within the appropriate range, it will be a wiring problem.
  • You should check carefully to see if the sensor is disconnected, the connector is bad or the wiring is close to the exhaust system.

Common Mistakes

Don’t make the mistake of immediate assumption that the HO2S is damaged and replace it.  You should follow the test technique to ensure that the wiring and other components are in acceptable condition. Most of these problems are related to the wiring that contacts the exhaust system.

How Serious is This?

There are multiple reasons for this code. However the vehicle can  work  normally by default, but it will consume excessive gasoline and perform poorly. It is very important to correctly diagnose the vehicle at the first time. 

In many cases, if the check engine light turns on immediately when starting, the OBD II system can be reset and the vehicle will operate normally.

What Repairs Can Fix the Code

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  • Check all cables related to the sensor. If the cables are in poor condition, they must be replaced. In addition, please ensure that there is a considered distance between the cable and the exhaust system.
  • Perform continuity, voltage, ground, and resistance tests on all relevant cables. Compare the results with the manufacturer’s specifications. Pay particular attention to the resistance value. If the value obtained is not within these specifications, replace the cable and remove the code.
  • If the code returns after completing all wiring checks, please remove the oxygen sensor and check its resistance. The value you get should meet the manufacturer’s specifications. It must be a specific resistance to operate the sensor correctly. If this is not the case, please replace the O2 sensor.

Related Codes

  • P0053 – Heated oxygen sensor Heater Resistance (Bank 1 Sensor 1)
  • P0054 – Heated oxygen sensor Heater Resistance (Bank 1 Sensor 2)
  • P0055 – Heated Oxygen Sensor Heater Resistance (Bank 1 Sensor 3)
  • P0059 – Heated oxygen sensor Heater Resistance (Bank 2 Sensor 1)
  • P0060 – Heated oxygen sensor Heater Resistance (Bank 2 Sensor 2)
  • P0061 – Heated Oxygen Sensor Heater Resistance (Bank 2 Sensor 3)


The OBD-II scanner error code P0053 can cause a serious problem if unresolved for an extended period, could cause significant damage to your engine, oxygen sensors, PCM, or other components of your vehicle. In latter cases, you may also find that an unfixed P0053 code can lead to the expensive replacements of various engine components.

P0053 Code – What Does It Mean & How To Fix It