P0234

DTC P0234

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 engine control module (ECM) monitors the boost pressure sensor signal for abnormal values. If the ECM detects that the boost pressure sensor signal is excessively high, this DTC will set.

Condition for Running the DTC
- The battery voltage is between 10-16 volts.
- The engine is running.
- DTC P0237, P0238, P2228 or P2229 is not set.

Condition for Setting the DTC
- The ECM detects that the excessive high boost pressure for longer than 3 seconds.

Action Taken When the DTC Sets
- The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
- The ECM limits fuel injection quantity less than 70%.

Condition for Clearing the DTC
- A current DTC, clears when the ignition is turned OFF.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
- High resistance in the boost pressure sensor return circuit may set this DTC.
- Check the waste gate for a sticking or stuck condition. Refer to Waste Gate Operation in the Engine Mechanical section.
- Use the 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. Use the scan tool data list values for nominal sensor readings.
- The fuel with which gasoline was mixed may set this DTC.

Test Description
The numbers below refer to the step number on the diagnostic table.
2. A skewed boost pressure sensor value (shifted to a higher pressure) can set this DTC. The Boost Pressure on the scan tool should read nearly barometric pressure with the key ON and engine OFF.
3. A skewed barometric pressure (BARO) sensor value (shifted to a lower pressure) can set this DTC. The BARO on the scan tool should read nearly surrounding barometric pressure.

DTC P0234

Schematic Reference: Engine Controls Schematics

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