What are the Symptoms of a bad Boost Pressure Sensor? | How to replace a bad Turbo Boost Sensor?

Your vehicle contains multiple sensors to ensure the efficient working of the engine. These sensors monitor the performance of different parts and send information to the powertrain control module (PCM). The PCM utilizes the information of these sensors to maintain the air-fuel ratio and many other functionalities. Your vehicle also contains a turbo boost pressure sensor. It detects the boost pressure within the intake manifold. This article mainly explains the bad turbo boost pressure sensor symptoms, causes, and its replacement cost.

What is a Boost Pressure Sensor?

A boost pressure sensor (BPS) uses to monitor the boost pressure within the intake manifold. The powertrain control module (PCM) utilizes the information of the BPS sensor to determine the correct amount of fuel, measure the ideal ignition timing, and actuate the turbocharger wastegate.

Boost Pressure Sensor

The boost pressure sensors are most commonly used on turbocharged engines to deliver barometric pressure data to improve engine efficiency.

The boost pressure sensor of your vehicle works very similarly to the MAP sensor. Like the MAP sensor, the BPS sensor determines absolute pressure and measures the airflow pressure and speed in the intake manifold.

Working of Boost Pressure Sensor

A turbo boost pressure sensor uses to measure the absolute pressure in front of the throttle valve. The powertrain control module (PCM) of your car utilizes the information of this sensor to determine the boost pressure correction value and air density in the intake manifold.

By utilizing the information of the turbo boost sensor, the PCM determines the amount of fuel that the engine cylinder needs to maintain an optimal air-fuel mixture.

Your vehicle requires a sufficient amount of air-fuel mixture to ensure the efficient working of the engine. An efficient working boost pressure sensor not only makes the engine more powerful but also runs efficiently and gets the most out of every drop of fuel. When this sensor goes bad, you may face drivability such as poor acceleration, rough idling, poor fuel economy, or engine stalling.

Boost Pressure Sensor Location

The boost pressure sensor is most commonly located in the boost pipes between the turbocharger and the intake manifold.

turbo Boost Pressure Sensor Location

This sensor may also be placed in the intake manifold of some vehicles. In this area, the sensor may also record the boost pressure of your vehicle’s turbocharger or supercharger without anything interfering.  

It’s a fairly easy spot near the top of the engine, but you may have to remove a few other parts to access it. But in some vehicle models, the boost pressure sensor is the easiest component to find and access.

Symptoms Of a Bad Boost Pressure Sensor

When the turbo boost pressure sensor goes bad, it produces one or more of the below-given symptoms:

  • Check engine light illumination
  • Increased or decreased engine performance
  • Decrease or increase in boost pressure
  • Failed emission test
  • Idling
  • Hard starting condition

1) Check Engine Light Illumination

The check engine light illumination is one of the most common symptoms of a bad turbo boost pressure sensor. In particular, your PCM may trigger the P0236 code as it detects a faulty boost pressure sensor. If you have this engine code, you should immediately inspect your vehicle’s pressure sensor. However, the P0236 code may trigger due to some other causes.

check engine light

A possible electrical problem must be ruled out, and you need to ensure the supercharger or turbocharger is working efficiently. If there is a potential problem, the boost pressure sensor will do exactly what it is supposed to and alert you about a potential problem.

2) Increased or Decreased Engine Performance

The main function of the turbo boost pressure sensor is to tell the PCM the actual performance of the supercharger or turbocharger. If this sensor doesn’t report the correct performance of the supercharger or turbo, the PCM will adjust to an incorrect reading due to that it will reduce or improve the overall performance of your engine.

poor engine performance due to bad boost pressure sensor

However, a bad boost pressure sensor may lead to a big reduction in the turbocharged engine’s performance than the performance of the supercharged engine, but engine degradation may occur in both engines. This is because, in the case of a supercharged engine, the PCM does not know the performance of the supercharger; due to that it cannot improve the engine’s performance.

But in the case of turbocharged engines, the PCM may fully cut the turbo pressure, which causes significantly reducing the engine performance.

On rare occasions, your PCM may also increase the turbo pressure, which causes to improve the performance of your turbo engine. This may badly damage the internal parts of your engine. Therefore, you should address a faulty boost pressure sensor as soon as possible.

3) Decrease or Increase in Boost Pressure

As mentioned in the above symptoms, a bad boost pressure sensor may decrease or increase the engine performance. This is caused due to an increase or decrease in the turbo pressure.

Few vehicles contain a turbo gauge that allows you to see the current turbo pressure. If you find that the pressure is more or less than normal under high load, you could definitely have a faulty boost sensor.

4) Failed Emission Test

If you live in an area that requires you to pass an emissions test in order for you to register your vehicle, a bad boost pressure sensor may likely cause your vehicle to fail the emission test. A bad BPS sensor may increase the emission of exhaust gases or turn on the check engine light.

Emissions Test failure

5) Idling

Rough idling is one of the common symptoms of a bad turbo boost pressure sensor. This sensor helps to control the air and fuel entry in the combustion chamber. An improper air-fuel ratio may cause excessive engine vibrations when idling or random jumps at idle speed.

Rough Idling due to faulty turbo boost sensor

6) Hard Starting Condition

A faulty BPS sensor may also cause engine staring issues. The PCM of your vehicle uses the boost pressure sensor data to determine the air pressure before starting the engine.

The engine is very sensitive to the proper air-fuel mixture at the starting moment; therefore, the incorrect reading can cause a too small amount of fuel to be delivered to the engine, and as a result, the engine may not start at all.

How to clean the Boost Pressure Sensor?

  1. First of all, park your car on a level surface. Apply the parking brakes and lift the car’s hood.
  2. Now, find the boost pressure sensor. This sensor is most commonly installed in the intake manifold near the throttle body. Use the manufacturer’s manual to easily locate the sensor.
  3. Carefully pull the power plug out of the sensor body. Before removing the sockets, depress the lock pins by using a flat screwdriver.
  4. Use a simple socket set or wrench to loosen and remove the locking screw/belt.
  5. Gently eliminate the sensor from the intake pipe.
  6. Buy a sensor cleaner to eliminate the contamination from the sensor. You shouldn’t touch the sensor elements without wearing gloves. Properly spray on all elements of the sensor, wipe away excess with a microfiber cloth and dry them in the air for a minimum of 4 minutes.
  7. Install the sensor back in its original position. Fully tighten the bolts/screws. You shouldn’t overtighten the bolts/screws!
  8. Check the electrical connections and wires of the boost pressure sensor for damage or corrosion. Maximum issues linked with a bad turbo sensor are electrical in nature and are almost always caused by damaged or corroded wires.
  9. Attach the sockets to the sensor.
  10. After properly tightening all the parts, turn on your car engine and let it idle. Get in the car for a quick test drive and see if the Check Engine Light comes on again. If a clogged or dirty sensor is causing the problem, cleaning the sensor will quickly restore engine performance.

Boost Pressure Sensor Replacement Cost

The replacement cost of the turbo boost pressure sensor varies according to your living area, labor cost, and the type of part’s brand. The average replacement cost of the boost pressure sensor is from $170 to $220.

FAQ Section

What does a turbo boost sensor do?

A turbo boost sensor uses to monitor the boost pressure within the intake manifold. The powertrain control module (PCM) utilizes the information of this sensor to determine the correct amount of fuel, measure the ideal ignition timing, and actuate the turbocharger wastegate.

Can I drive with a Faulty Boost Pressure Sensor?

Yes, you can drive with a faulty boost pressure sensor. However, driving with a defective boost pressure sensor is not recommended. In case of a bad turbo boost sensor, your PCM may also often direct too much power to the turbo, which may be potentially dangerous for the engine.

A faulty sensor may produce different drivability issues, such as poor acceleration, rough idling or engine stalling.

A bad turbo boost sensor may also badly damage your engine. This is because extreme boost pressure will overheat your engine and damage various components of your engine. Therefore, as your sensor goes bad, you should immediately replace it.

What happens when a turbo actuator goes bad?

If the electronic actuator cannot open the nozzle ring assembly vanes during acceleration, the turbocharger will also not be able to work properly. If the vanes are placed in the closed position, the engine may stall, or the turbine may Overspeed.

What are the Boost Pressure Sensor fault codes?

When your boost pressure sensor goes bad, your PCM triggers one of the below-given codes:

  • P0235
  • P0236
  • P0237
  • P0238
  • P0239
  • P0240
  • P0241

What causes a Turbo Boost Sensor to fail?

The major causes are contamination and normal wear and tear. If your vehicle’s check engine light is illuminating, it may also mean the turbo boost sensor is slow to respond, and you need to replace it.

What are the symptoms of a bad Turbo Boost Sensor?

  • Check engine light illumination
  • Increased or decreased engine performance
  • Decrease or increase in boost pressure
  • Failed emission test
  • Idling
  • Hard starting condition

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