DTC P0236 Turbocharger Boost System Performance. Generic Unit Repair 1999

For 1990-2009 cars only

Makes 🢒 Generic 🢒 1999 🢒 Unit Repair 🢒 DTC 🢒 DTC P0236 Turbocharger Boost System Performance

Circuit Description

The PCM operates a solenoid to control boost. This solenoid is normally open. By providing a ground path the PCM energizes the solenoid which then allows vacuum to pass to the wastegate valve. During normal operation, the PCM compares its wastegate duty cycle signal with the boost signal and makes corrections in the duty cycle accordingly.

Conditions for Running the DTC

•	The PCM performs this DTC diagnostic continuously.

•	The engine speed is greater than 1800 RPM.

•	The fuel rate is greater than 20 cu mm.

Conditions for Setting the DTC

•	The measured boost pressure is less than or equal to 20 kPa from desired (internal to PCM) minus baro adjustment.

•	All diagnostic conditions met for 10 seconds.

Action Taken When the DTC Sets

•	A poor performance condition will exist.

•	The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails.

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The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the Failure Records will store this information. If the diagnostic reports a failure on the second consecutive drive trip, the Freeze Frame records the operating conditions at the time of failure and updates the Failure Records.

Conditions for Clearing the MIL/DTC

•	The PCM will turn the MIL off after three consecutive trips without a fault condition.

•	A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.

•	The use of a scan tool

Diagnostic Aids

A vacuum leak or a pinched vacuum line may cause a DTC P0236. Check all vacuum lines and components connected to the hoses for leaks or sharp bends. Check vacuum source. A possible EGR DTC will store if there is a problem with the vacuum source. Also check for proper vacuum line routing.

The turbocharger wastegate actuator uses a pulse width modulated vacuum solenoid that causes vacuum to fluctuate under normal conditions. A steady vacuum reading indicates a restricted or plugged solenoid vent filter or solenoid vent orfice.