P0236: Turbocharger/Supercharger Boost Sensor A Circuit Range/Performance
Severity: medium
What it means: The engine computer thinks the boost pressure sensor (the sensor that reads how much air pressure the turbo is making) is giving a reading that doesn't make sense compared with what the engine is doing. Sometimes the sensor is bad, but often the real problem is ice, oil or water in the intake, a stuck valve, or a leak that throws the reading off.
Safe to drive? Usually drivable gently. Power is often reduced, which makes merging and passing risky, so get it checked soon.
Common symptoms
- Check engine light
- Low power, especially on cold mornings
- Hesitation when you press the gas
- Often stored with P0299, P00C7 or P2227 on GM small turbo engines
Likely causes, ranked
- Ice or water in the charge air cooler or intake in very cold weatherShop
- Contaminated or stuck charge air bypass valveShop
- Faulty boost pressure sensor or wiringDIY or shop
- Boost leak in hoses or intercooler pipesDIY or shop
Vehicle-specific notes
- 2015–2018 Chevrolet Trax: GM bulletin 16-NA-405 lists this code (with P0299, P2227 and P00C7) on the 1.4L turbo Trax and Encore when ice builds up in the crankcase vent (PCV) tube or the charge air cooler in very cold weather (0°F or below). Owners on the Trax Forum describe low power that goes away once the engine warms up. Read the full answer · Source
What it means: The engine computer thinks the boost pressure sensor (the sensor that reads how much air pressure the turbo is making) is giving a reading that doesn't make sense compared with what the engine is doing. Sometimes the sensor is bad, but often the real problem is ice, oil or water in the intake, a stuck valve, or a leak that throws the reading off.
Severity: Medium. Safe to drive? Usually drivable gently. Power is often reduced, which makes merging and passing risky, so get it checked soon.
DIY or shop?
DIY for checking boost hoses, clamps and the sensor plug. A shop is better for checking actual vs. desired boost with a scan tool.
Before you replace parts
- Read all stored codes and freeze-frame data. Note the outside temperature when it set.
- If it only happens in deep cold and clears once warm, tell the shop about GM bulletin 16-NA-405 (icing).
- Check boost hoses and clamps for leaks, and the sensor plug for corrosion.
- Ask the shop to inspect the charge air bypass valve for water, oil or sludge before replacing the turbo or sensors.
Safety / mechanic note
Verify with a mechanic. Reduced power can make merging and passing unsafe. A code points to a circuit or system, not always a specific part.