Skip the auto shop - Our mechanics make house calls

P0239 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Malfunction

Check Engine Light

P0239 code definition

Turbocharger Boost Sensor B Circuit Malfunction

What the P0239 code means

P0239 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects an intake boost pressure sensor B input malfunction when compared to the manifold pressure sensor (MAP) when the engine is at idle; turbocharger boost should be zero.

What causes the P0239 code?

  • The turbo boost sensor B and the MAP sensor voltage input do not correlate the same reading with the engine at idle or when the key is first turned on and the engine is off.

  • The turbo boost pressure sensor B is contaminated or clogged.

  • The turbo boost pressure sensor B is slow to respond to changing pressure, most likely from age deterioration.

What are the symptoms of the P0239 code?

  • The Check Engine Light will be illuminated and the code will be set in memory.

  • The engine turbocharger boost pressure may be turned off by the ECM causing the engine to lack power on acceleration.

How does a mechanic diagnose the P0239 code?

  • Scans codes and documents the freeze frame data in order to verify the problem
  • Clears the codes to verify whether the concern comes back
  • Checks the operation of the boost pressure sensor compared to the MAP sensor
  • Checks the turbo boost sensor B for blockage of the sensor port
  • Checks the turbo boost sensor B connector for loose or corroded pins

Common mistakes when diagnosing the P0239 code?

Follow these simple guidelines to prevent misdiagnosis:

  • Check the boost pressure sensor hose for obstructions or kinks.

  • Verify the electrical connections to the sensor are secure and pressure hoses are not leaking or kinked.

How serious is the P0239 code?

  • The boost pressure in the intake can give you a lot of power. If the turbo boost sensor B is malfunctioning, then the ECM may disable the turbo boost and you would have a lack of power.

What repairs can fix the P0239 code?

  • Replacing the boost sensor if it is not giving the correct input pressure reading to the ECM

  • Repairing or replacing the hoses and connections to the turbo boost sensor if kinks or blockage of the lines are present

  • Repairing the wiring to the sensor or replacing the connection

Additional comments for consideration regarding the P0239 code

Code P0239 is triggered by the intake boost sensor B indicating a malfunction condition that the ECM cannot determine the true cause. The most common failure is the boost sensor in most cases.

Need help with a P0239 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Post a question and get free advice from our certified mechanics.

ASK A QUESTION

More related articles

P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem What the P0121 code means P0121 is a generic OBD-II code which indicates that the Engine Control...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...


Related questions

Q: Engine stopped running while driving and will not start again.

Hey there. As you know, this P0340 code indicates the camshaft position sensor is either faulty or not connected properly. The camshaft position sensor monitors the speed of the camshaft providing the ECU with this information. The ECU uses this...

Q: My check engine light came on and the it was diagnosed as op128 so I got gas screwed on my cap and my light turned off how is this

First, a trouble code P0128 does have to do with coolant, but it is not the level. This code is set when the relationship between the coolant temperature sensor and the intake air temperature sensor don't increase at a predetermined...

Q: The service engine soon appeared

If I understand you correctly the engine starts, then immediately shuts off? This could be anything from the need for an oil and filter change service, overheating problem, or failure of engine management components. I would recommend a "Car Is...