Boost Pressure Sensor

What Is a Boost Pressure Sensor & P0236?

In Engine by 6 Comments

If you have ever driven or owned a car with a turbocharged engine, then you probably know what the “Boost Pressure Sensor” is.

It is the sensor that measures the boost pressure and sends the information to the engine control unit.

However, for those who don’t have much of an idea, we will discuss the boost pressure sensor, it’s functions and how to prevent it from getting damaged in detail.

What Is a Boost Pressure Sensor?

Boost Pressure Sensor

A boost pressure sensor is a part of a turbocharged engine which measures and regulates the air pressure in the intake manifold and controls the boost level of the supercharged engine. A BPS monitors the speed and airflow pressure in the intake manifold and ensures that the engine remains at its optimum level and is receiving the ideal air and fuel supply.

A turbocharged engine without a boost pressure sensor will generate enough power that it will get damaged due to a high temperature.

The boost pressure sensor can be found inside the intake pipe near the throttle valve.

How Is a Turbocharged Engine Different from a Naturally Aspirated Engine?

Before diving into detail about the boost pressure sensor, let’s look at the difference between a regular engine and a turbocharged engine.

Every internal combustion engine uses two key ingredients: air (oxygen) and fuel. As the gas is burned by the engine, energy is generated which in turn powers the engine. The fuel relies on air supply for efficient combustion and in a regular engine, the air supply is limited. Generally, 15 times more air than fuel is required for the process.

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A turbocharged engine consists of two main components: a turbine and a compressor. Both of these components spin at a ridiculously high speed and in turn allow the engine to suck in more air and generate higher power.

What Is the P0236 Code?

The OBD codes do not point out the direct component which may be facing an issue, but rather they point out to an area where the technician should look for the problem. A vehicle which generates the P0236 code indicates that there is a problem with the turbocharger boost sensor. This code is triggered when the Engine Control Module (ECM) detects that the boost pressure sensor does not match the specification as the manifold pressure sensor (MAP) or the barometric pressure sensor (BARO) when the engine is idle.

Why Does the P0236 Code Appear?

There are several reasons why the P0236 code is triggered. The most common causes are:

  • The turbo boost pressure reading does not match the MAP or BARO when the engine is switched off.
  • The boost pressure sensor is clogged or contaminated with dirt and debris.
  • The turbo boost pressure sensor is damaged and responding relatively slower to changing pressure.

Possible Symptoms

When the P0236 code is triggered, the PCM reacts by entering into an engine management failure mode, as it ignores the real manifold pressure reading and assumes another reading, limiting the engine capability. Here are some of the symptoms you might face:

  • Check engine light activates
  • The turbo boost will be turned off and the engine will not generate enough power
  • Due to failing pressure, there would be a loss in acceleration. Check boost leak symptoms.
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Fixing the P0236 Code

There are several ways to fix the P0236 code and the best way is to take the car for an inspection to an authorized dealer. The auto-specialist will use an advanced scanner to identify the problem and it will be easier to fix it. Besides that, here are the two common troubleshooting techniques you can try.

Remove and replace the boost sensor if it is providing the ECM with an incorrect pressure reading.

Check the hoses and connections to the turbo boost sensor and see if they are clogged or have any blockages. In that case, cleaning these connections will solve the problem.

If you want to do it yourself at home, you can read the values with an OBD2 code scanner and get a wiring diagram to measure the sensor. The sensor normally has three wires; one 5-12 volt power, one ground and one signal. You can check that you have all these before replacing the sensor. You can also measure the sensor itself by checking if you have any ohms or an open circuit between the pins. For exact ohm measurement, get a wiring diagram with the part number on the sensor.

Guide to Purchasing a Boost Pressure Sensor

Depending on your car make and model, you can get the OEM replacement part from the authorized dealership. You can also check auto-shops online or search eBay for car components. Here are some of the key things to keep in mind before buying a boost pressure sensor.

Highly Sensitive Boost Pressure Sensor Which Ideally Adjusts Fuel Injection:

A faulty boost pressure is unable to sync with the ECU which is responsible for releasing the right amount of fuel to the engine’s combustion chamber. Thus, it is recommended to search for a high-quality boost pressure sensor which has high sensitivity and also uses vacuum pressure as its reference point if the engine control unit is equipped with it.

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Select the Exact Same Boost Pressure Sensors as the Ones Fitted in Your Car Currently:

The boost pressure sensors differ in every car make and model and you should only choose the specific component which is advised in your car’s owner manual. Choosing a universal component is not recommended. You can often find the part number on the sensor itself. Just google the part number and see what results you get.

Advanced Sensor With Extras

Some high-tech sensors offer some extras such as a three-way joint, turbo sensor extension and more.

Turbo Sensor Extension:

If your car makes use of additional gauges, you’ll need a turbo sensor extension wire to connect to these gauges. This extension is sold separately and is not required if you drive with just the regular company-fitted gauges.

Warranty and Money-Back Guarantee:

Make sure the dealer from who you are buying the component offers an after-sales service, warranty and a money-back guarantee in case the sensor turns out to be faulty.

Always remember to fix any engine related issues as soon as possible as prolonging certain problems can cost you hundreds of dollars and even put your life at risk.

If you want to find a list of all your cars sensor. Check out this article: Car Sensors

6 thoughts on “ What Is a Boost Pressure Sensor & P0236? ”

  1. My boost pressure sensor is on the hot side of the intercooler? Not on the cool side,why.Ford s max 2.0t ecoboost. 2011.

  2. Is the boost pressure sensor the same with air intake temperature sensor. They look the same.

  3. Hi Magnus,
    I have an Opel Insignia (2.0 CDTI engine).
    Lately , an intermitent fault presents once per every 300 km roughly during high speed on the highway only , stating turbo boost overpressure.
    The turbo compressor operation checked and stated OK. The turbo control valve has been replaced as a precaution , but issue remained. Do you think that the boost sensor might be a reason for the issue? Thanks

  4. Hello. MB c 220 cdi 2007 150hp t model
    Abs, esp. comes on then disappears for a while.
    Engine management light on,
    Lack of power. Intermittent fault, transmission and engine power fine then lack of power on hills.
    Historic abs sensors codes
    Abs Sensors and rings checked/replaced
    Conductor plate replaced, transmission serviced. Transmission control module tested for voltages, solenoids resistance checked.
    Has a battery change prior to faults appearing, Ecu was disconnected. Historic low power codes.
    Drives good now with good power until intermittent lack of power fault. Lack of power uphill, shifts tooo quick at low revs. On level or downhill power returns. Intermittent no power to overtake,
    Engine serviced,

    Tried to replace brake light switch but there isn’t one even though autodoc search found several for the vehicle. Looking at the sensor at the brake booster but clutching at straws again.

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