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P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance

Check Engine Light

P0240 code definition

Turbocharger Boost Sensor B Circuit Range/Performance

What the P0240 code means

P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost pressure sensor B input circuit range or performance to be out of specifications when compared to the manifold pressure sensor (MAP) or the barometric pressure sensor (BARO) at idle and with the key on, engine off, before the engine is started.

What causes the P0240 code?

  • The turbo boost pressure sensor B does not correlate the same voltage input to the ECM with the MAP or BARO sensors at engine idle or when the key is on and the engine is off.

  • The turbo boost pressure sensor B is contaminated or clogged with debris or carbon deposits.

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

What are the symptoms of the P0240 code?

  • The Check Engine Light will be illuminated and code P0240 is set in ECM memory.

  • The engine turbo boost may be turned off by the ECM and the engine will lack power.

  • The engine may lack some power during acceleration if the boost sensor is failing to register the correct amount of boost pressure.

How does a mechanic diagnose the P0240 code?

  • Scans codes and document 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 for blockage of the sensor port, or boost sensor hose or line.

  • Checks the turbo boost sensor connector for loose or corroded pins in the connector.

  • Checks the sensor pressure lines for kinks or damaged lines.

Common mistakes when diagnosing the P0240 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 clean and secure, and the pressure hose is not leaking, kinked or cracked.

How serious is the P0240 code?

  • If the turbo boost pressure sensor is out of range or having performance problems, then the ECM will disable the turbo boost on some vehicles. This could cause the vehicle to have a lack of power on acceleration, and engine performance problems.

What repairs can fix the P0240 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 due to kinks or blockage of the lines

Additional comments for consideration regarding the P0240 code

Code P0240 is triggered by the intake boost sensor indicating a range or performance problem that the ECM determines is out of known specifications. The most common failure is the boost sensors slow response due to lower performance issues with the sensor as it ages.

Need help with a P0240 code?

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