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P1153 – 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.


P1153 is an OBD-II Code that refers to HO2S Insufficient Switching Bank 2 Sensor 1


A P1153 code is a generic diagnostic trouble code that occurs when the PCM/ECM detects a signal voltage input indicating an issue with the HO2S sensor which is installed in the exhaust manifold. It controls the unburned oxygen in the exhaust once it comes out from the engine. It also monitors oxygen levels to measure the fuel mixture to make it as optimal as possible.

The PCM also monitors the voltage signals sent through the heater element circuit, which it interprets as the condition of the circuit by comparing its voltage to the car’s factory expectations. The Check Engine light on the dashboard is illuminated by the Error Code P1153 when there is a fault with the signal.


Common causes for this code include:

  • Bad HO2S Bank 2 Sensor 1
  • Bank 2 Sensor 1 is shorted or open Bank 2 Sensor 1 harness
  • HO2S Bank 2 Sensor 1 circuit has poor electrical connection
  • Faulty PCM (rare)


The symptoms of a P1153 code are:

  • Illuminated Check Engine Light 
  • Irregular motor operation


To diagnose a P1153 DTC code, a technician would:

  1. Scan for codes in the ECM and look at the freeze frame data for failure.
  2. Visually inspect the oxygen sensor’s wiring harness and connectors for any signs of corrosion or damage.
  3. Check the HO2S connector pins for any corrosion or damage.
  4. Test the HO2S connector pins with an ohm meter to check continuity between the ECM and the HO2S.
  5. Check the HO2S heater element circuit for any shorts or opens.
  6. Check the HO2S Bank 2 Sensor 1 for proper function.
  7. If all of these tests are passed, then the PCM might need to be replaced as the root cause of the code.

Common mistakes

The following are some of the most common mistakes that a technician may make when diagnosing a P1153 code:

  • Not thoroughly inspecting all the wiring and connectors.
  • Not checking the continuity between the PCM and the HO2S.
  • Not properly testing the HO2S Bank 2 Sensor 1 for proper function.
  • Faulty PCM.

How serious is this?

A P1153 code is considered a moderate to severe code and should be addressed as soon as possible. The code can cause the engine to run irregularly and the Check Engine light will be illuminated.

What repairs can fix the code?

The following are solutions that may fix this problem:

  • Repair or replace any faulty parts such as wiring, connectors, or hoses.
  • Clean or replace the oxygen sensor.
  • Replace the PCM (rare).

Related codes

A P1153 is related to and may be accompanied by the following codes:

P0130 – Bank 2 Sensor 1 Malfunction

P0150 – HO2S Heater Circuit Malfunction

P0420 – Catalyst System Efficiency Below Threshold (Bank 2)


In conclusion, the P1153 code is a diagnostic trouble code that refers to a problem with the HO2S Bank 2 Sensor 1. The code can cause the engine to run irregularly and the Check Engine light will be illuminated. There are many possible causes for this code, such as a bad oxygen sensor, a short or open in the wiring harness, or a faulty PCM. The code should be addressed as soon as possible to prevent further damage to the engine.