P2564 Code: Turbocharger Boost Control Position Sensor Circuit Low

What the P2564 code means

On variable geometry turbos and on turbos with an electronic wastegate, a sensor reports the position of the mechanism. The computer compares it with the command to control boost pressure.

The sensor gets a 5 V reference and a ground from the computer and returns a signal between roughly 0.5 and 4.5 V. A low signal, the kind the P2564 code reports, usually comes from a short to ground on the signal wire or from a missing reference voltage.

It is usually built into the turbo actuator, where it is exposed to high temperatures.

To confirm it, unplug the component with the key on and watch what happens to the reading or the code. If the value jumps to the opposite extreme, the wiring is fine and the component itself is the one pulling the signal to ground. If nothing changes, look for the short in the wire, starting where the harness rubs against the engine, the chassis or the exhaust.

P2564 code symptoms

• Check engine light on.
• The computer does not control turbo pressure well and may limit power.

Likely causes of the P2564 code

1. Signal wire shorted to ground because the harness rubs against the engine, the chassis or a bracket.
2. Shorted reference supply. If several sensors fail at once, suspect the shared reference voltage.
3. Damaged sensor with an internal short.
4. Connector with water or corrosion that creates a path to ground.

How to diagnose the P2564 code step by step

1. Read the sensor value on the scan tool and compare it with what you expect.
2. Inspect the connector for corrosion, water or loose pins.
3. Check supply and ground with the key on: the reference should be correct and the ground voltage drop should be under 0.1 V.
4. Measure the signal with the connector plugged in and see whether it changes with the operating condition.
5. Do a wiggle test on the harness with the scan tool in graph mode.
6. Check continuity of each wire to the computer, which should be under 1 ohm.

How to fix the P2564 code

• Repair the connector or the wiring.
• Replace the sensor if the tests confirm it is bad.
• Correct the real condition if there is one.
• Clear the codes and verify with a road test.

Technical reference data

• 5 V reference; signal between 0.5 and 4.5 V depending on position.
• Approximate values only: check the manufacturer data for your vehicle.

Brand-specific notes

The unplug test is the quickest way to split the sensor from the wiring on a low signal. Do it before you buy a part for the P2564 code.

P2564 on Variable Geometry Diesels and Electric Wastegate Gas Engines

Common on diesels with a variable geometry turbo (Volkswagen, Ford, Hyundai and Kia, Chevrolet Duramax) and on gasoline engines with an electric wastegate.

Frequently asked questions about P2564