P0237

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 monitors the boost sensor signal for high and low limits.

Conditions for Running the DTC
The ignition switch is in the ON position

Conditions for Setting the DTC
^ The boost pressure is less than 40 kPa.
^ The condition was met for 2 seconds.

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 may be caused by the following:
^ Poor connections.
^ Rubbed through wire insulation.
^ Broken wire inside the insulation.

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

Test Description
The number(s) below meter to the step number(s) on the Diagnostic Table.
2. This step will determine if DTC P0237 is the result of a hard failure or an intermittent condition.
3. This Step simulates conditions for a DTC P0237. If the PCM recognizes the change, the PCM and the signal circuit are OK.
9. In this step, components that share the 5 volt reference can cause the reference voltage to be shorted to ground. This can be checked by disconnecting each component one at a time, including the PCM while checking for continuity on that circuit to chassis ground.