Fault code P0250 – turbocharger wastegate solenoid “B” high

Fault code P0250 is called “Turbocharger Wastegate Solenoid “B” High” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P0250

OBD-II fault code P0250 is a general fault code, most often defined as a high signal level of the turbocharger bypass solenoid valve “B”. It is set when the Powertrain Control Module (PCM) detects a common fault in the circuit. This is used to regulate the operation of the turbocharger bypass valve.

Fault code P0250 – turbocharger wastegate solenoid

The turbocharger is designed to compress the intake air, which the engine uses to increase power and save fuel. It consists of two chambers, one chamber contains a turbine wheel and the other a compressor wheel.

Exhaust gases from the engine pass through the chamber containing the turbine wheel and rotate it. The compressor wheel, attached to the other end of the shaft, is then driven.

As the speed of the engine increases, the volume and velocity of the exhaust gas also increases. Thereby increasing the speed of the compressor impeller, where the intake air is strongly compressed by the compressor impeller before it enters the engine. This is the boost pressure that needs to be controlled. This is done to prevent engine damage caused by overcharging conditions.

In a fully functional supercharger control system, the PCM will activate the control valve at all times to keep the supercharger pressure at the optimum level. This is done using engine speed data, throttle position. Other values, such as intake air temperature and others, are also taken.

If the charge control system is fully functional, the PCM will use the combined input from all of the sensors involved. However, if the charge control circuitry fails, the PCM can no longer effectively control the boost pressure.

Thus, if the PCM detects a fault in the turbocharger bypass valve control circuits, it will set code P0250. This means that the PCM cannot effectively control the boost pressure. Additional codes may also be displayed. Some of which may cause it to go into fail-safe or emergency mode. This is done as a precaution and also to protect the engine.

Symptoms of vehicle malfunctions

The main signal that an error P0250 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. The “Check engine” control lamp on the control panel will light up (the code will be stored as a fault).
  2. Other related fault codes may also be present.
  3. Loss of power due to engine turbocharger shutdown may be observed.
  4. Increased noise, and there may also be ringing and rattling of the turbocharger or piping.
  5. Ignition jerking/missing.
  6. Contamination of the spark plugs.
  7. The engine may lack power during acceleration.
  8. Increased fuel consumption.

The severity of the P0250 problem is medium, but you should understand that when the turbocharger pressure increases, the engine power increases. If the turbocharger boost pressure sensor fails, the vehicle’s PCM may shut down the turbocharger. This will result in a drop in engine power.

Factors that can cause this error code

The error code P0250 can mean that one or more of the following problems have occurred:

  • Defective bypass valve.
  • Charge pressure regulator solenoid is defective.
  • Faulty turbocharger boost pressure sensor.
  • Damaged, burned, shorted, disconnected, corroded charge pressure sensor wires or connectors.
  • Short circuit or break in wiring harness between sensor and PCM.
  • Relief valve actuator is jammed.
  • Sometimes faulty PCM is the cause.

How to fix or reset OBD-2 code P0250

Some suggested steps for troubleshooting and fix the error code P0250:

  1. Read all stored data and error codes with an OBD-II scan tool.
  2. Clear the error codes from the computer memory and test-drive the vehicle to find out if error P0250 appears again.
  3. Check the operation of the turbocharger boost pressure relief valve.
  4. Inspect the turbocharger boost pressure sensor for blockage.
  5. Test the connector and wiring for damage, looseness, and corrosion.

Diagnose and repair of problems

Turbines typically spin at incredible speeds of 100,000 to 150,000 rpm. They are intolerant to imbalance or a lack of clean oil in the bearing.

The diagnostic process for the P0250 error is best started with the most common turbo problems. These will require tools such as a vacuum gauge and a dial gauge.

Checking the vacuum

Make sure the engine is running properly, with no ignition skips or codes related to a faulty detonation sensor. Then, check for leaks at the turbocharger outlet, intercooler, and throttle body.

Inspect the intake manifold for leaks of any kind, including vacuum hoses. Remove the lever from the throttle valve. Manually operate the valve, looking for a jammed valve causing a drop in boost.

Measuring boost pressure, turbocharger inspection

Locate the vacuum with no holes in the intake manifold and install a vacuum gauge. Start the engine. At idle the engine should have a vacuum of 1-1.5 atmospheres. If less than 1 atmosphere then the catalytic converter is defective and will not allow boost.

Quickly accelerate the engine to 5000 rpm and release the throttle, observing the vacuum gauge indicating the boost pressure. If the boost pressure rises above 1.3 atmospheres, then the bypass valve is bad.

Stop the engine and let it cool down. Remove the turbine exhaust hose and look inside to make sure the blades are not rubbing the housing. Look for bent or missing blades or oil in the turbocharger. Rotate the blades by hand, looking for resistance indicating turbocharger malfunction.

Inspect the oil lines from the cylinder block to the center bearing and the return line from the bearing to the oil pan for leaks. Place a dial gauge on the turbine outlet and rotate the turbine shaft. If the axial play exceeds 0.003, the center bearing is defective.

Solenoid and wiring

If after all the checks there is no problem, but code P0250 is still present, check the electrical components. The solenoid and associated circuits should be tested.

Disconnect the wiring harness from the bypass damper pressure regulator solenoid and test the control circuit. If the solenoid is open or shorted, there will be no or no resistance. If this is the case, it must be replaced because it has failed.

Verify that 12 volts are present in the solenoid supply circuit. They should be showing when the ignition is on. If they are not present, or if they are present when the ignition is off, repair the wiring from the PCM to the solenoid.

Check that the pressure control solenoid pressure control valve supercharger is securely grounded. Connect a test lamp to the plus end of the battery, and touch the other end to the solenoid valve ground circuit. Operate the control solenoid. If the control light does not come on, this indicates a faulty circuit.

On which vehicles does this problem occur most frequently

Fault code P0250 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Audi
  • Ford
  • Jeep (Wrangler)
  • Mercedes-Benz
  • Mitsubishi
  • Volkswagen
  • Volvo

Fault code P0250 can sometimes be found with other errors. The most common are the following: P0247, P0248, P0249.

Video

Rate article
Share to friends
AutoNevod | Technical description of OBD-2 car faults and their solution
Add a comment