HomeTrouble CodesP2593

P2593 — Turbocharger Speed Sensor B Circuit

Manufacturer-specificPowertrain (engine & transmission)

The P2593 code indicates that the Engine Control Module (ECM) has detected a malfunction in the electrical circuit of the turbocharger speed sensor 'B'. This sensor measures the rotational speed of the turbocharger's turbine shaft, and a circuit fault can disrupt boost pressure control, leading to reduced engine performance and potential turbocharger damage.

Symptoms

What causes it — most likely first

1. Faulty turbocharger speed sensor B

The sensor itself may have failed internally due to heat, vibration, or age, causing an incorrect or absent signal to the ECM.

2. Damaged wiring or poor electrical connection at the sensor

Corrosion, loose terminals, or broken wires in the sensor connector or harness can interrupt the circuit, leading to intermittent or permanent signal loss.

3. Short to ground or open in the sensor circuit

Wiring insulation damage or a break in the circuit can cause a short to ground or an open circuit, preventing the sensor signal from reaching the ECM.

4. Turbocharger mechanical fault affecting sensor reading

Excessive shaft play, bearing failure, or foreign object damage can alter the sensor's target wheel or gap, producing erratic or out-of-range signals.

5. Engine Control Module (ECM) malfunction

A rare internal fault in the ECM can cause it to misinterpret or fail to process the sensor signal, but this should only be considered after all other causes are ruled out.

How it's diagnosed

  1. Scan for all diagnostic trouble codes and record freeze frame data to identify the conditions when the code set.
  2. Visually inspect the turbocharger speed sensor, its wiring, and connector for damage, corrosion, or loose connections.
  3. Test the sensor's resistance or output voltage according to manufacturer specifications using a digital multimeter or oscilloscope.
  4. Check the sensor circuit for continuity, shorts to ground, or shorts to voltage between the sensor and the ECM.
  5. Inspect the turbocharger for mechanical issues such as excessive shaft play, oil contamination, or damaged turbine blades that could affect sensor readings.
  6. If no other faults are found, verify ECM power, ground, and signal processing using a scan tool to monitor live data and perform a wiggle test on the harness.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

What does the P2593 code mean?

It means the engine computer has detected an electrical circuit problem with the turbocharger speed sensor 'B', which monitors how fast the turbo spins. This can affect boost control and engine performance.

Can I drive with a P2593 code?

You can drive short distances, but it's not recommended. The engine may enter a reduced power mode, and continued driving could lead to poor fuel economy, increased emissions, or turbocharger damage.

Does this code mean my turbocharger is bad?

Not necessarily. The code points to a circuit issue, so the sensor, wiring, or connector is often at fault. However, a mechanical turbo problem can sometimes trigger the code, so a thorough diagnosis is needed.

Is the PCM likely to be the cause of P2593?

No, PCM failure is very rare for this code. Many drivers are mistakenly told to replace the PCM, but the problem is almost always the sensor, wiring, or connector. The PCM should only be suspected after all other possibilities are ruled out.