P0238

DTC P0238 Turbocharger Boost Sensor Circuit High Voltage

Circuit Description

The boost pressure sensor is located in the air induction tubing. The boost pressure sensor is a transducer that varies voltage according to changes in the air pressure inside the air tubing. The sensor has the following circuits.

^ 5 volts reference circuit
^ Low reference circuit
^ Boost pressure sensor signal circuit

The boost pressure sensor provides a signal to the ECM on the signal circuit which is relative to the pressure changes in the air tubing. The ECM should detect a low signal voltage at a low boost pressure such as low engine load. The ECM should detect high signal voltage at a high boost pressure such as high engine load. If the ECM detects an excessively high signal voltage this DTC will set.

Condition for Running the DTC

^ DTCs P0237 P0642 and P0643 are not set.
^ The battery voltage is between 10 to 16 volts.
^ The ignition switch is ON.

Condition for Setting the DTC

^ The ECM detects that the boost pressure sensor signal voltage is more than 4.7 volts for 1 second.

Action Taken When the DTC Sets

^ The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type A.
^ The ECM uses a boost pressure substitution of default value.
^ The ECM limits fuel injection quantity.
^ The ECM inhibits EGR control.
^ The ECM inhibits turbocharger control.
^ The ECM inhibits DPF regeneration control.
^ The ECM inhibits cruise control.

Condition for Clearing the DTC

^ Refer to DTC Type Definitions for Condition for Clearing the MIL/DTC - Type A.

Diagnostic Aids

^ If an intermittent condition is suspected refer to Intermittent Conditions in this section.

Circuit/System Testing DTC P0238