P0236
PowertrainTurbocharger/Supercharger Boost Sensor "A" Circuit Range/Performance
The turbocharger or supercharger boost pressure sensor 'A' is reporting values outside the expected range. The sensor that reports actual boost pressure to the ECU is misbehaving, either reading inaccurately or with a circuit fault.
ⓘ Information only. This page provides general educational information about fault code P0236. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0236 mean?
P0236 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Turbocharger/Supercharger Boost Sensor "A" Circuit Range/Performance.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light
- • Loss of power, often progressive
- • Possibly limp mode if the ECU thinks boost has gone wild
- • Hesitation under acceleration, particularly from low revs
- • On some cars, slight surging or fluttering at part-throttle
- • Possible black smoke under load on a diesel
Possible causes
Causes commonly associated with P0236, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Failed boost pressure sensor reading inaccurately (most common, sensors fatigue with age)
- 2. Sensor port blocked with carbon or oil, the sensor reads through a small port that can gunk up
- 3. Vacuum line cracked or detached on cars with vacuum-referenced sensors
- 4. Wiring damage at the connector, often from heat exposure
- 5. Connector corroded or backed out
- 6. Genuine boost issue, the sensor is reading correctly but the turbo is producing wild pressures
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Read live data on commanded vs actual boost throughout the rev range, an obvious pattern usually emerges
- 2. Visual inspect the sensor for oil contamination, oily film on a sensor that's been wet from a turbo seal leak fouls the reading
- 3. Check vacuum lines on cars with vacuum-referenced sensors
- 4. Test sensor electrically against spec at known reference pressures (with a hand vacuum/pressure pump)
- 5. If the sensor is healthy and the boost values are genuinely wild, look at the turbo, wastegate, or variable-vane mechanism instead
- 6. Address any oil leak that's contaminating the sensor before fitting a new one, otherwise it'll fail again in months
Common questions about P0236
Difference between P0236 and P0237? +
P0237 is specifically the sensor reading low (signal too low). P0236 is broader range/performance fault, the signal is there but values aren't right. Both point to similar diagnostic approach, test the sensor and check for contamination first.
Could a recent service have caused this? +
Possibly. After turbo work or intercooler replacement, sensors can be disturbed. If P0236 appeared shortly after a workshop visit, check whether the connector has been properly seated and the sensor port hasn't picked up debris during the work.
Will a remap fix it? +
No, and it may make it worse. Remap doesn't fix faulty sensors. If the sensor is reporting wrong values, a new tune will work from incorrect data and may push the engine harder than it should. Diagnose and fix the fault before considering performance modifications.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →