Cruze

DTC P0236, P0237, or P0238

The boost pressure sensor is integrated with the inlet air temperature (IAT) sensor. The boost 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, inlet air temperature (IAT), barometric pressure (BARO) and the efficiency of the charge air cooler. The boost pressure sensor and integrated intake air temperature (IAT) sensor have the following circuits:

The boost pressure sensor provides a signal voltage to the engine control module (ECM), relative to the pressure changes, on the inlet 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 (34.80 PSI). The least pressure that occurs is when the vehicle is idling or decelerating and it is equal to the BARO.

P0237 00

The ECM detects that the boost pressure sensor voltage is less than 0.19 V for more than 4 s continuously, or 50 s cumulative.

P0238 00

The ECM detects that the boost pressure sensor voltage is greater than 4.8 V for more than 4 s continuously, or 50 s cumulative.

DTCs P0236 00, P0237 00 and P0238 00 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. Ignition ON, observe the scan tool Manifold Absolute Pressure (MAP) Sensor parameter, the Boost Pressure Sensor parameter, and the BARO Sensor parameter.
2. Engine idling, observe the scan tool and compare the Boost Pressure Sensor parameter to the BARO Sensor parameter. They should be within 4 kPa (0.58 PSI) of each other.
3. 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 (2.9 PSI) of each other.
4. 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 Q42 Turbocharger Wastegate Solenoid Valve.

•	Any hairline fractures of the B65 Intake Manifold Pressure and Air Temperature Sensor housing

•	Loose or improper installation of any components

•	An air flow restriction

•	Any vacuum leak

•	Any pinholes or breaks in the vacuum hoses attached to the Q42 Turbocharger Wastegate Solenoid Valve.

•	Any restrictions in the vacuum hoses attached to the Q42 Turbocharger Wastegate Solenoid Valve.

•	Improper routing or connecting of the vacuum hoses on the charge air cooler, the Q40 Turbocharger Bypass Solenoid Valve, and the Q42 Turbocharger Wastegate Solenoid Valve.

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

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

2. Ignition OFF, disconnect the harness connector at the B65 Intake Manifold Pressure and Air Temperature Sensor.
3. Ignition OFF for 90 s, test for less than 5 Ω between the low reference circuit terminal 1 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 Engine Control Module.

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

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

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

5. Verify the scan tool turbocharger Inlet Pressure Sensor parameter is smaller than 1 kPa (0.14 PSI).

⇒	If less than the specified range, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

6. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5 V reference circuit terminal 3. Verify the scan tool turbocharger Inlet Pressure Sensor is greater than 250 kPa (36.26 PSI).

⇒	If smaller 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 Engine Control Module.

7. If all circuits/connections test normal, replace the B65 Intake Manifold Pressure and Air Temperature Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.