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P0236 – Turbocharger Boost Sensor A Circuit Range/Performance (OBD2)

P0236 means "Turbocharger Boost Sensor A Circuit Range/Performance". The boost pressure sensor signal is electrically present but implausible: it does not match what the control unit expects for the current operating conditions or from other sensors. This is a performance fault, not a broken wire.

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P0236 quick summary

Fault codeP0236
MeaningTurbocharger Boost Sensor A Circuit Range/Performance
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityMedium
Can I drive?Usually yes, in limp mode. With an overboost code, avoid full throttle – excessive boost can damage the engine and turbo.
Repair cost€30 – €1,500

How the boost pressure sensor works

The boost pressure sensor measures the pressure the turbocharger produces so the engine control unit can regulate boost and protect the engine; P0234 means boost has exceeded the safe limit.

The boost pressure sensor sits in the charge air pipe or intake manifold after the intercooler, often combined with an air temperature sensor. It works like a MAP sensor with a wider range: a 5 V reference, ground and a signal that rises with pressure.

The control unit compares the measured boost with the target. If the signal is electrically out of range, implausible, or boost goes above the safe limit (overboost, P0234), it reduces power to protect the engine and turbo. Sensor B codes refer to a second sensor on engines with two turbochargers or two measuring points.

Oil mist from the crankcase ventilation and turbo seals often contaminates the sensor; boost leaks, sticking wastegates or vanes and faulty control solenoids cause range and overboost codes.

On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 16620 (P0236). Both numbers mean the same fault.

Symptoms of P0236

  • Limp mode, loss of power
  • Check Engine light on
  • Surging power or sudden power cut under acceleration (overboost)
  • Black smoke
  • Turbo or boost control codes alongside

Most common causes of P0236 (most likely first)

Mechanic's Pro Tip

If boost and barometric pressure differ by more than about 50 mbar with the engine off, the boost sensor is faulty. If they agree and the code persists, look at the turbo control instead.

  1. 1.Boost pressure sensor worn, contaminated or out of calibration

    Most likely

    The signal drifts slowly, so it is still within the electrical limits but wrong.

  2. 2.Mechanical problem in the system the boost pressure sensor measures or controls

    For example a leak, a sticking part or a restriction that really changes the measured value.

  3. 3.High resistance in a connector or ground

    Corrosion causes a voltage drop that shifts the reading.

  4. 4.Failed boost pressure sensor

  5. 5.Wiring fault or 5 V reference problem

  6. 6.Sticking turbo vanes or wastegate (overboost)

  7. 7.Faulty boost control solenoid or vacuum hose (overboost)

Step-by-step diagnostic guide

  1. 1

    Read codes and compare pressures

    Read all codes. With the engine off, the boost sensor should read the same as the barometric pressure.

  2. 2

    Compare live data with expected values

    Read the boost pressure sensor values in live data and compare them with related readings (engine speed, load, temperature or pressure) and with the specification. A value that is electrically fine but wrong for the conditions confirms a performance fault – then check the mechanical side before replacing the part.

  3. 3

    Inspect and clean the sensor

    Remove the sensor, check it for oil and clean it carefully with electrical contact cleaner.

  4. 4

    Check reference, ground and signal

    Measure the 5 V reference and ground and watch the signal rise smoothly with boost.

    Multimeter: Key on, engine off: equal to barometric pressure (about 1,000 mbar near sea level).

  5. 5

    Log specified vs actual boost

    During a full-load acceleration, compare specified and actual boost. Actual boost overshooting the target points to a sticking wastegate or vanes.

  6. 6

    Repair and verify

    Replace the sensor or fix the boost control fault, clear codes and repeat the test drive.

Frequently asked questions

Can I keep driving with P0236?

Usually yes, in limp mode. With an overboost code, avoid full throttle – excessive boost can damage the engine and turbo.

How much does it cost to fix P0236?

Typical repair costs are 30 € – 1500 €, depending on the cause and the vehicle. The most common fixes are: boost pressure sensor worn, contaminated or out of calibration; mechanical problem in the system the boost pressure sensor measures or controls; high resistance in a connector or ground. Always confirm the cause with the tests above before buying parts.

What causes overboost (P0234)?

Usually a wastegate or VTG vanes that do not open, a faulty boost control solenoid or a cracked vacuum hose. Less often a faulty boost sensor reading too high.

Is the boost sensor the same as the MAP sensor?

On many turbo engines yes – the MAP sensor in the intake manifold measures boost. Some engines have both.

What is the difference between P0236 and similar codes?

P0236 belongs to a group of codes for the same component that differ in the type or location of the fault: P0234 – Engine Overboost Condition; P0235 – Turbocharger Boost Sensor A Circuit Malfunction; P0237 – Turbocharger Boost Sensor A Circuit Low; P0238 – Turbocharger Boost Sensor A Circuit High; P0239 – Turbocharger Boost Sensor B Circuit Malfunction; P0240 – Turbocharger Boost Sensor B Circuit Range/Performance. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.