P0236

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

Conditions for Setting the DTC
The engine speed greater than 2400 RPM (test 1).
or
The engine speed is greater than 1800 but less than 2400 RPM (test 2).

Conditions for Setting the DTC
^ The boost pressure is greater than, less than, or equal to 20 kPa from desired (internal to PCM) (test 1).
^ The conditions were met for 10 seconds.
or
^ The boost pressure is greater than, less than, or equal to 20 kPa from desired (internal to PCM) (test 2).
^ The conditions were met for 12 seconds.

Action Taken When the DTC Sets
^ A poor performance condition will exist.
^ The PCM will reduce maximum fuel.
^ The PCM will disable the Torque Converter Clutch (TCC).

Conditions for Clearing the MIL/DTC
^ A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other emissions related diagnostic.
^ The Scan tool will clear the DTC codes.

Diagnostic Aids
A vacuum leak or a pinched vacuum line may cause a DTC P.O.W. Check all of the vacuum lines and the components connected to the hoses for any leaks or sharp bends. Check the vacuum source. Also check for proper vacuum line routing.

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

Test Description
The number(s) below are the step number(s) on the Diagnostic Table.
3. This will check the wastegate solenoid and the filter. A plugged filter will not allow the solenoid to vent, which will cause an overboost condition.
5. This step checks the turbocharger wastegate actuator for vacuum leaks. The actuator must hold a vacuum.
6. This step will check for vacuum leaks at the lines.
9. This step will check for a skewed boost pressure sensor.