P2566 OBD-II Trouble Code: Turbocharger Boost Control Position Sensor Circuit Intermittent

P2566 code definition

A P2566 trouble code indicates the detection by the Powertrain Control Module (PCM) of an abnormal reading from the turbocharger boost control position sensor circuit. This trouble code is most commonly associated with a P2562, P2563, P2564, and P2565 code.

What the P2566 code means

The storage of a P2566 trouble code is triggered when the PCM receives a sensor input voltage signal from the turbocharger boost control position sensor circuit that is less or greater than that specified by the manufacturer.

What causes the P2566 code?

A P2566 trouble code is caused by a variety of problems in the air intake system of a vehicle, including a vacuum leak, dirty air cleaner, or a stuck wastegate. Other common causes of a P2566 code are loose bolts between the turbocharger and the exhaust manifold, a faulty intercooler, faulty boost sensor, defective intercooler, faulty wiring in the boost sensor circuit, a loose or damaged connector in the boost sensor, and a failure on the part of the turbo. Failure of the turbo is often associated with an insufficient oil supply to the turbocharger mainshaft, resulting in a problem with the turbo bearing, including a failure, in addition to a cracked turbo housing, and damaged impeller blades.

What are the symptoms of the P2566 code?

The symptoms of a P2566 trouble code include reduced acceleration, smoke from the exhaust, fouled spark plugs, excessive noise from the turbocharger, and higher-than-normal engine and transmission temperatures. Other common symptoms include a hissing sound issuing from the turbocharger wastegate and surrounding hoses and lowered engine performance. Some other indicators of this code are abnormal boost pressure levels, the storage of engine misfire, and knock sensor codes. The mechanic can also look for cylinder detonation caused by high engine temperatures.

How does a mechanic diagnose the P2566 code?

In addition to an advanced scanner, to properly diagnose a P2566 trouble code, a mechanic needs a boost pressure gauge, vacuum gauge, dial indicator set, and a handheld vacuum pump. When the mechanic has gathered the tools needed, they should proceed with the diagnosis as follows:

• Clear up any codes associated with engine knocking and misfires.
• Inspect all turbo intake and intercooler hoses for leaks, cracks, and general tightness.
• Inspect the turbo for stability, looking for any loose bolts.
• Use a booster gauge to actuate the throttle while inspecting the turbo. Observe the boost gauge while elevating the pressure above 19 pounds.
• Inspect all wiring and connectors for damage.
• Use a vacuum pump to engage the actuator valve by hand to see if the wastegate opens and closes as it should.
• Allow the engine to cool down and visually inspect the inside of the turbo for any standing oil. Also make sure the impeller, which drives the air flow through the turbo, is in good shape and operational.
• Inspect the vacuum levels of the turbocharger with a vacuum gauge attached.
• Test the electrical circuitry and connectors of the turbo for proper voltage and grounding using a digital volt/ohmmeter.
• Clear the code and test drive the vehicle to see if the code returns.

Common mistakes when diagnosing the P2566 code

Mechanics often make the mistake when clearing a P2566 trouble code of not clearing any debris or obstructions from the turbocharger oiling system. This, in turn, leads to an additional failure of the turbo upon clearing the code. The mechanic should also test the functioning of the turbocharger wastegate and electrical circuit to prevent further problems and turbo failure.

How serious is the P2566 code?

In addition to indicating a failure of the turbocharger, a P2566 trouble code can also show signs of increased engine temperature, lowered vehicle performance, and knocking and misfires within the engine as symptoms, affecting acceleration and overall engine horsepower. In addition, cylinder detonations associated with this trouble code can also cause engine damage.

What repairs can fix the P2566 code?

After making a diagnosis, the mechanic should make the following repairs:

• Replace or tighten any loose intake and intercooler hoses and clamps attached to the turbo.
• Tighten any loose bolts attaching the turbo to the engine.
• Repair the wastegate if faulty.
• Replace or repair the turbo and any components, such as a broken impeller.
• Repair or replace any damaged or faulty wiring and connectors. Also, make sure all connectors are firmly attached.

Need help with a P2566 code?

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