The intake air pressure sensor is integrated with the intake air temperature (IAT) sensor 2. The intake air pressure sensor measures the range of pressures between the turbocharger and the throttle body. The sensor used on this engine is a three atmosphere sensor. Pressure in this portion of the induction system is affected by engine speed, throttle opening, turbocharger boost pressure, intake air temperature (IAT), barometric pressure (BARO), and the efficiency of the charge air cooler (CAC). The intake air pressure and temperature sensor has the following circuits:

The sensor provides a signal voltage to the engine control module (ECM), relative to the pressure changes, on the intake air pressure 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 C DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust.
2. If DTC P0299 is set, verify the proper operation of the charge air bypass valve. Refer to Turbocharger Cleaning and Inspection.
3. Use the scan tool output controls to command the TC Bypass Solenoid ON and OFF. An audible click should be heard and felt.
4. Use the scan tool output controls to command the TC Wastegate Solenoid ON and OFF. An audible series of clicks should be heard and felt between 20-90 percent.
5. Determine the current vehicle testing altitude. Ignition ON, 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.
6. Use the scan tool and compare the MAP Sensor parameter to the Boost Pressure Sensor parameter during a WOT acceleration at the time of the 1-2 shift. The readings should be within 20 kPa of each other.
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 CAC, and the TC wastegate actuator

•	Any hairline fractures of the boost pressure sensor housing

•	Loose or improper installation of any components

•	An air flow restriction

•	Any vacuum leak

•	Any pinholes or breaks in the 3 vacuum hoses attached to the TC wastegate actuator

•	Any restrictions in the 3 vacuum hoses attached to the TC wastegate actuator

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

•	Any type of air leak between the turbocharger and the throttle body, including the CAC assembly.

•	Verify that an exhaust leak does not exist, including the mating surface area between the turbocharger and the exhaust manifold.

2. Ignition OFF for 90 seconds, disconnect the harness connector at the intake air pressure and temperature sensor.
3. Test for less than 5 Ω between the low reference circuit terminal 1 or A and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, test for 4.8-5.2V between the 5V reference circuit terminal 3 or C and ground.

⇒	If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

⇒	If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. Verify the scan tool Boost Pressure Sensor parameter is greater than 275 kPa.

⇒	If less than the specified range, test the signal circuit terminal 4 or D for a short to ground. If the circuit tests normal, replace the K20 ECM.

6. Install a 3A fused jumper wire between the signal circuit terminal 4 or D and the low reference circuit terminal 1 or A. Verify the scan tool Boost Pressure Sensor parameter is less than 1 kPa.

⇒	If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

7. If the circuits test normal, test or replace the intake air pressure and temperature sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.