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P0235Turbocharger/Supercharger Boost Sensor "A" Circuit

What it means

The ECU has detected an electrical fault in the boost pressure sensor circuit: the signal is missing, stuck or outside the range the sensor can produce. The boost pressure sensor measures the pressure after the turbo or supercharger.

Symptoms

  • Limp mode with low power
  • Black smoke or poor acceleration
  • Check engine light

Common causes

  • Open or shorted signal, 5 V reference or ground wire
  • Corroded, loose or water-filled connector
  • Failed boost pressure sensor
  • Fault on the shared 5 V reference (another sensor pulling it down)

What to check first

  1. With the key on, measure the 5 V reference and the ground at the sensor connector
  2. Back-probe the signal and compare it with live data while wiggling the harness
  3. Check for other codes on the same 5 V reference (e.g. P0641, P0651)
Can I drive with P0235? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0235: questions and answers

What does P0235 mean?

P0235: Turbocharger/Supercharger Boost Sensor "A" Circuit. The ECU has detected an electrical fault in the boost pressure sensor circuit: the signal is missing, stuck or outside the range the sensor can produce. The boost pressure sensor measures the pressure after the turbo or supercharger.

What are the symptoms of P0235?

Limp mode with low power. Black smoke or poor acceleration. Check engine light.

What causes P0235?

Open or shorted signal, 5 V reference or ground wire. Corroded, loose or water-filled connector. Failed boost pressure sensor. Fault on the shared 5 V reference (another sensor pulling it down).

How do you diagnose P0235?

1. With the key on, measure the 5 V reference and the ground at the sensor connector 2. Back-probe the signal and compare it with live data while wiggling the harness 3. Check for other codes on the same 5 V reference (e.g. P0641, P0651)

Can I drive with P0235?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.