HomeTrouble CodesP2590

P2590 — Turbocharger Boost Control Position Sensor B Circuit Intermittenterratic

Manufacturer-specificPowertrain (engine & transmission)

Code P2590 indicates that the engine control module is detecting an intermittent or erratic electrical signal within the turbocharger boost control position sensor 'B' circuit. This means the sensor responsible for tracking the turbo actuator's position is providing inconsistent or dropping out readings, which disrupts the computer's ability to regulate boost pressure accurately.

Symptoms

What causes it — most likely first

1. Faulty boost control position sensor

The sensor itself may be failing internally, causing its signal to drop out or become erratic when it heats up or vibrates.

2. Wiring or connector issues

Frayed, corroded, or loose wiring and connectors can cause intermittent contact, leading to an erratic signal to the control module.

3. Mechanical turbocharger actuator fault

If the wastegate or actuator mechanism is sticking or binding, the sensor will report erratic position changes as it struggles to move.

4. Fluid contamination in connector

Oil or coolant intrusion into the sensor connector can cause short circuits or corrupt the electrical signal.

5. Faulty PCM/ECM

In rare cases, an internal failure within the powertrain control module can cause it to misinterpret the sensor signal, though this is highly uncommon.

How it's diagnosed

  1. Visually inspect the sensor 'B' connector and wiring harness for fraying, corrosion, or loose pins, particularly near the turbocharger where heat and vibration are highest.
  2. Using a diagnostic scan tool, monitor the live data for sensor 'B' while wiggling the wiring harness to see if the signal drops out, indicating an intermittent connection.
  3. Test the sensor's resistance and voltage outputs at various positions to verify they match the manufacturer's specifications.
  4. Check the turbocharger wastegate or actuator for physical binding, sticking, or vacuum leaks that could cause erratic mechanical movement.
  5. If the sensor, wiring, and mechanical components all test fine, verify the PCM's power and ground circuits before considering a control module failure.

Code facts & related codes

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

Frequently asked

Can I drive my car with a P2590 code?

While the vehicle may still be drivable, it is not recommended. Erratic boost control can cause unpredictable acceleration, reduced power, or potential engine damage if the turbo overboosts or underboosts under load.

Does this code mean my turbocharger is broken?

Not necessarily. The code specifically points to an electrical circuit issue with the position sensor. While a mechanically failing wastegate actuator can cause this, the most likely culprit is a failing sensor or damaged wiring, not the entire turbocharger.

Will replacing the PCM fix code P2590?

Almost never. Mechanics commonly warn against replacing the PCM for this code because an intermittent circuit code is usually caused by a bad sensor, corroded connector, or chafed wire. The PCM is very rarely the cause and should only be replaced after all wiring and sensor issues are absolutely ruled out.