Error Code P0236 is defined as Turbo Charger Boost Sensor A Range/Performance. This code applies to all turbocharged vehicles. Its difference in other makes is usually on the method by which the pressure is measured in the intake manifold.

It’s a generic trouble code, meaning it appears in all vehicles equipped with OBD-II, particularly those made since 1996 up to present. Specifications on the definition, troubleshooting and repairs of course, vary form one make and/or model to another.

For GM vehicles for example, it is defined as Turbocharger Boost System Performance.

For Dodge diesel pickups, it is described as MAP Sensor Too High Too Long.

Definition

Error Code P0236 is triggered when the PCM (powertrain control module, also called as ECM or engine control module) detects that the Intake Boost Pressure Sensor A input circuit range or performance is runs outside of its specifications as compared to MAP (manifold pressure sensor) or BARO (barometric pressure sensor) at idle, with key on, engine off, prior to starting.

Common Symptoms

The usual symptoms of this error code are:

  • Check Engine light illuminated
  • PCM turned off the engine turbo boost, causing lack of power to the engine
  • Lack of power on acceleration if boost sensor is failing to register to right amount of boost pressure

Possible Causes

There are multiple possible causes for this error code, but it always starts with a problem in the turbo boost pressure sensor. Some of possible causes include:

  • The turbo boost pressure sensor doesn’t link the same reading with the MAP or BARO at engine idle at key on, engine off.
  • The turbo boost pressure sensor A is clogged or contaminated with carbon deposits or other debris.
  • The turbo boost pressure sensor A responds too slowly to the changing pressure due to age and deterioration.

Other possible causes include:

  • Fault in vacuum supply, broken, collapsed, or pinched vacuum lines
  • Defective control solenoid
  • Defective PCM (rare)

How to Check

As with other trouble codes, mechanics start their troubleshooting for this Error Code P236 by scanning and documenting the freeze frame data to verify the problem.

Then, the mechanic will clear the codes to check whether the error code comes back.

Then, they will check the operation of the boost pressure sensor and compare it to the MAP sensor.

After that, they will proceed on checking the turbo boost sensor and look for any signs of blocking on the sensor port, hose or lines.

Lastly, they will check the connector of the turbo boost sensor to see if there are any loose or corroded pins.

This is just the standard process most mechanics follow. To start the diagnosis, you should definitely consult with the TSB (technical service bulletin) of your particular vehicle. This is a known problem, which means there are known fixes for it provided by the manufacturer, saving you time and money during diagnosis.

How to Fix

Replacing the defective boost sensor (the one that is not giving the correct input pressure reading to the PCM) usually fixes the problem. For defective hoses and connections of the turbo boost sensor of course, they should be repaired if not replaced, particularly those with blockage and kinks.

As said earlier, this error code causes lack of power on acceleration. This is because vehicles with only one sensor have their turbo boost disabled by the PCM, as the turbo boost sensor stays out of range or experiencing performance problems.