P0238

Circuit Description
The Powertrain Control Module (PCM) operates a solenoid to control boost. This solenoid is normally open. By providing a ground path, the PCM energizes the solenoid which allows 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 to the duty cycle accordingly.

Conditions for Running the DTC
The engine speed is less than 3506 RPM.

Conditions for Setting the DTC
The boost pressure is greater than or equal to 4.8 volts (202 kPa).

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive drive trip the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the Failure Records 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
An intermittent can be caused by the following:
^ Poor connections
^ A rubbed through wire insulation
^ A broken wire inside of the insulation

Check for opens or shorts to ground in the signal wire, or an open in the 5 volt reference circuit.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
3. This step will determine if the PCM is responding to a low signal voltage. This will indicate that the PCM is OK.
9. If the scan display is still less than or equal to 9 kPa by disconnecting the PCM the short to voltage is in the wiring.
10. If the voltmeter value stays the same by disconnecting the PCM the short to battery voltage is in the wiring.