The boost pressure sensor is integrated with the intake air temperature (IAT) sensor. The boost pressure sensor measures the range of pressures between the turbocharger and the throttle body. Pressure in this portion of the induction system is affected by the following:

The sensor provides a signal voltage to the engine control module (ECM), relative to the pressure changes, on the boost pressure sensor signal circuit. Under normal operation the greatest pressure that can exist in this portion of the induction system at ignition ON, engine OFF is equal to the BARO. When the vehicle is operated at wide-open throttle (WOT) the turbocharger can increase the pressure to near 240 kPa. The least pressure that occurs is when the vehicle is idling or decelerating, and it is equal to the BARO.

P0234

P0299

P0234

The ECM detects that the actual boost pressure is greater than the desired boost pressure for greater than 3 seconds continuously or 50 seconds cumulative.

P0299

The ECM detects that the actual boost pressure is less than the desired boost pressure for greater than 4 seconds continuously or 50 seconds cumulative.

DTCs P0234 and P0299 are Type B DTCs.

DTCs P0234 and P0299 are Type B DTCs.

Use a solution of dish soap and water in a spray bottle to pinpoint any air leaks.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Turbocharger System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0033, P0034, P0035, P0236, P0237, P0238, P0244, P0245, or P0246 is not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Verify the exhaust system is not restricted. Refer to Restricted Exhaust.
3. If DTC P0299 is set, verify the proper operation of the turbocharger bypass solenoid valve. Refer to Turbocharger Cleaning and Inspection.
4. Ignition ON, command the Turbocharger Bypass Solenoid Valve ON and OFF with a scan tool. You should hear an audible click.
5. Command the Turbocharger Wastegate Solenoid Valve to 50 percent with a scan tool. You should hear an audible click.
6. Determine the current vehicle testing altitude. Observe the scan tool MAP Sensor parameter, the Boost Pressure Sensor parameter, and the BARO Sensor parameter. Compare the parameters to each other and to the Altitude Versus Barometric Pressure table.
7. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify the integrity of the entire air induction system including all turbocharger components by inspecting for the following conditions:

•	Any damaged components, including the turbocharger, the charge air cooler, and the turbo charger wastegate actuator solenoid valve

•	Damage to the boost pressure sensor

•	Loose or improper installation

•	An air flow restriction

•	Any vacuum leaks

•	Any pinholes or breaks in the vacuum hoses attached to the turbocharger wastegate solenoid valve

•	Any restrictions in the vacuum hoses attached to the turbocharger wastegate solenoid valve

•	Improper routing or connecting of the vacuum hoses on the turbocharger bypass solenoid valve , the bypass valve, and the turbocharger wastegate actuator solenoid valve

•	Any type of air leak between the turbocharger and the throttle body, including the charge air cooler.

•	Exhaust leaks

⇒	If a condition is found, repair as necessary.

2. Ignition OFF, remove B65 intake air pressure and temperature sensor but leave the electrical connector connected.
3. Connect the J 24460-01 Cooling System Pressure Tester to the turbocharger boost pressure sensor port with a suitable adapter. Engine running, observe the scan tool Boost Pressure Sensor parameter. Apply 6 psi to the turbocharger boost pressure sensor. Verify the scan tool Boost Pressure Sensor parameter responds to the applied pressure.

⇒	If the scan tool Boost Pressure Sensor parameter does not increase with the applied pressure, replace the B65 intake air pressure and temperature sensor.

4. Inspect the turbocharger oil supply lines for a restriction.

⇒	If restricted, repair or replace as necessary.

5. If all other components test normal, test or replace the turbocharger.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.