Can I drive with P0235?

Only gently and only to a workshop. Most engines go into limp mode, so power is capped and can drop under load. Avoid motorways, overtaking and towing until it is repaired.

What is the difference between P0235 and P0236?

P0235 is a general circuit fault: the signal is missing or electrically out of range. P0236 means the signal is electrically fine but the pressure it reports does not make sense. P0235 usually points to the wiring, connector or sensor, while P0236 more often means a boost leak, a clogged sensing port or a drifting sensor.

Where is the boost pressure sensor?

Usually in the charge air pipe between the intercooler and the engine, or on the intake manifold, held by one or two screws. On some engines it is combined with the charge air temperature sensor. Check the workshop information for your engine code, because some engines have both a boost sensor and a separate MAP sensor.

How much does it cost to fix P0235?

Cleaning and reseating the connector costs nothing to 50 euros. A new boost pressure sensor costs 40 to 140 euros fitted and is usually a quick job. A wiring repair runs 70 to 220 euros, mostly fault-finding time.

P0235: Turbocharger/Supercharger Boost Sensor "A" Circuit

Quick Answer

Not safe to drive

P0235 means the engine computer has found an electrical fault in the circuit of boost pressure sensor "A", the sensor that measures pressure in the intake after the turbo. The signal is missing, out of range or erratic, so the engine computer can no longer measure boost and normally limits boost and power to protect the engine. The usual causes are the sensor itself, its connector or its wiring, or a missing 5 V supply.

Severity: Moderate · Fuel System

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What does P0235 mean?

P0235 is a fuel system-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0235 and illuminates the check engine light.

Where it is on the car

Air filter
Turbocharger
Wastegate or boost control actuator
Intercooler
Boost pressure sensor
Throttle, intake manifold and engine

What are the symptoms of P0235?

If your vehicle has triggered P0235, you may notice one or more of these symptoms:

Check engine light on, often with a reduced power message
Limp mode with power capped
Slow, flat acceleration
Black smoke under load on some diesels
P0236 or P0238 stored alongside on some cars

What causes P0235?

Here are the most common causes of P0235:

Failed boost pressure sensor
: high
Corroded, oily or loose connector at the sensor
: high
Chafed or broken signal, reference or ground wire
: medium
Missing 5 V reference, sometimes pulled down by another sensor on the same supply
: medium
Wrong replacement sensor fitted
: low
Engine computer fault (rare)
: low

Is it safe to drive with P0235?

No - address this immediately. Drive gently and only as far as a workshop. Without a boost signal most engines go into limp mode, cutting power without warning under load, which makes overtaking and motorway merging unsafe. Avoid heavy throttle and towing until it is fixed.

How do you diagnose P0235?

Follow these steps to pinpoint the root cause of P0235:

Read all stored codes and the freeze frame. Other sensor codes at the same time point to a shared 5 V reference problem. A generic OBD2 reader shows the codes, the freeze frame and boost or MAP readings where the engine computer reports them.
With the ignition on and the engine off, compare the boost reading with the barometric and MAP readings: with no boost they should all read atmospheric pressure, roughly 95 to 105 kPa at sea level. A reading that is missing, stuck at an extreme or far off points to the sensor or its wiring.
Find the sensor, usually in the charge pipe or on the intake manifold, sometimes combined with the charge air temperature sensor. Unplug it and check the connector for oil, corrosion and damaged pins.
With the ignition on, measure the 5 V reference and the ground at the connector, then check the signal wire for continuity and shorts.
If the circuit is good, replace the sensor with the correct part for the engine code, clear the code and road-test, checking that boost rises smoothly under load.

How much does P0235 cost to fix?

Repair costs for P0235 vary depending on the root cause and your vehicle. Here are typical estimates:

Repair	Parts Cost	Labor Cost	Total Estimate	DIY Difficulty
Clean and reseat boost sensor connector	€0–€10	€0–€40	€0–€50	Easy
Replace boost pressure sensor	€20–€80	€20–€60	€40–€140	Easy
Repair boost sensor wiring or connector	€10–€40	€60–€180	€70–€220	Moderate

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0235 or indicate related issues:

Common questions about P0235

What does P0235 mean?: P0235 means the engine computer has found an electrical fault in the boost pressure sensor circuit. The signal is missing, out of range or erratic, so it can no longer measure the pressure the turbo is making, and it usually limits boost and power until the fault is fixed.
Can I drive with P0235?: Only gently and only to a workshop. Most engines go into limp mode, so power is capped and can drop under load. Avoid motorways, overtaking and towing until it is repaired.
What is the difference between P0235 and P0236?: P0235 is a general circuit fault: the signal is missing or electrically out of range. P0236 means the signal is electrically fine but the pressure it reports does not make sense. P0235 usually points to the wiring, connector or sensor, while P0236 more often means a boost leak, a clogged sensing port or a drifting sensor.
Where is the boost pressure sensor?: Usually in the charge air pipe between the intercooler and the engine, or on the intake manifold, held by one or two screws. On some engines it is combined with the charge air temperature sensor. Check the workshop information for your engine code, because some engines have both a boost sensor and a separate MAP sensor.
How much does it cost to fix P0235?: Cleaning and reseating the connector costs nothing to 50 euros. A new boost pressure sensor costs 40 to 140 euros fitted and is usually a quick job. A wiring repair runs 70 to 220 euros, mostly fault-finding time.

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