P0234

DTC P0234 Turbocharger Engine Overboost

Circuit Description

The boost pressure sensor is located in the air induction tubing. The sensor is a transducer that varies voltage according to changes in the air pressure inside the air tubing. The ECM monitors the boost pressure sensor signal for abnormal values. If the ECM detects that the sensor signal is excessively high this DTC will set. This indicates excessive high boost pressure.

Condition for Running the DTC

^ DTCs P0112 P0113 P0116 P0117 P0118 P0237 P0238 P0401 P0403 P0404 P0405 P0406 P042E P0602 P0642 P0643 P0652 P0653 P1125 P2227 P2228 P2229 and P268A 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 an excessive high boost pressure for longer than 3 seconds.

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 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

^ An open circuit or high resistance in the boost pressure low reference circuit may set this DTC.
^ Check the turbocharger nozzle control solenoid valve for a sticking.
^ Use a scan tool to verify the integrity of the boost pressure sensor signal. Compare the sensor values under all load conditions for an excessively high value.
^ The fuel with which gasoline was mixed may set this DTC.

Test Description

The numbers below refer to the step number on the Circuit System Testing.

3. A skewed boost pressure sensor value (shifted to a higher pressure) can set this DTC. The Turbocharger Boost Pressure on the scan tool should read near Barometric Pressure (BARO) with the key ON and engine OFF.

4. A skewed BARO sensor value (shifted to a lower pressure) may indicate a wrong boost pressure. The BARO on the scan tool should read near surrounding barometric pressure.

Circuit/System Testing DTC P0234