HomeTrouble CodesP2579

P2579 — Turbochargersupercharger Speed Sensor Circuit Rangeperformance

Manufacturer-specificPowertrain (engine & transmission)

The P2579 code indicates that the Powertrain Control Module (PCM) has detected a range or performance problem with the turbocharger or supercharger speed sensor circuit. This sensor monitors the rotational speed of the forced induction device, and the code sets when the signal is not within the expected parameters for current operating conditions.

Symptoms

What causes it — most likely first

1. Faulty turbocharger/supercharger speed sensor

The sensor itself may have failed internally, producing an erratic or out-of-range signal that the PCM cannot interpret correctly.

2. Damaged or corroded wiring/connectors

Shorts, opens, or high resistance in the sensor circuit can distort the signal, leading to a range/performance fault.

3. Poor electrical connection at the sensor

Loose, corroded, or pushed-out terminals at the sensor connector can cause intermittent or incorrect signals.

4. Mechanical fault in the turbocharger/supercharger

Binding, excessive shaft play, or damage to the forced induction device can cause the actual speed to deviate from expected values, triggering the code.

5. PCM software or internal fault (rare)

In very rare cases, a software glitch or internal PCM failure may misinterpret a valid sensor signal. This should only be considered after all other causes are ruled out.

How it's diagnosed

  1. Visually inspect the turbocharger/supercharger speed sensor, wiring harness, and connectors for obvious damage, corrosion, or loose connections.
  2. Check the sensor's resistance or output voltage (depending on sensor type) with a multimeter and compare to manufacturer specifications.
  3. Use a scan tool to monitor the speed sensor signal while the engine is running; look for erratic, missing, or out-of-range readings.
  4. Inspect the turbocharger/supercharger for mechanical binding, excessive shaft play, or damage that could affect rotational speed.
  5. Verify the PCM is receiving proper power and ground, and check for any related technical service bulletins (TSBs) or software updates.
  6. If all other tests pass, suspect a PCM fault, but this is extremely rare; perform a thorough wiring check before condemning the PCM.

Code facts & related codes

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

Frequently asked

What does the P2579 code mean?

It means the engine computer has detected a signal from the turbocharger or supercharger speed sensor that is out of the expected range or performance, indicating a potential sensor, circuit, or mechanical issue.

Can I drive with a P2579 code?

You may be able to drive, but performance will likely be reduced and the forced induction system may not work correctly. Continued driving could lead to further damage, so prompt diagnosis is recommended.

Is the PCM likely to be the cause of P2579?

No, the PCM is rarely the cause. The problem is almost always the speed sensor, wiring, or a mechanical issue with the turbocharger/supercharger. Replacing the PCM should only be considered after all other possibilities are exhausted.

What are common repairs for this code?

Common repairs include replacing the turbocharger/supercharger speed sensor, repairing damaged wiring or connectors, or addressing mechanical faults in the forced induction system.