DTC P0236, P0237, or P0238
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DTC P0236, P0237, or P0238
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DTC P0236
Turbocharger Boost System Performance
DTC P0237
Turbocharger Boost Sensor Circuit Low Voltage
DTC P0238
Turbocharger Boost Sensor Circuit High Voltage
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Diagnostic Fault Information
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Circuit
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Short to Ground
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High resistance
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Open
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Short to Voltage
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Signal Performance
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5 V Reference
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P0107, P0193, P0236, P0642
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P0236, P0237
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P0107, P0236
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P0036, P0193, P0236, P050 P0606, P0643
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P0234, P0236, P0299
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Intake air pressure signal
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P0237
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P0236, P0237
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P0238
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P0238
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P0236
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Low Reference
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-
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P0234, P0236, P0238
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P0098, P0099, P0238
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-
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-
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Boost Pressure Sensor
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Circuit
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Short to Ground
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Open
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Short to Voltage
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Operating Conditions:
Engine Running at various operating conditions
Parameter Normal Range:
BARO to 240 kPa
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5 V Reference
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20-80 kPa
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30-80 kPa
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20-80 kPa
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Boost Pressure Sensor
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0 kPa
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276 kPa
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276 kPa
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Low Reference
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-
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276 kPa
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-
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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.
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.
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Conditions for Running the DTC
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P0236
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•
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DTC P0106, P0107, P0108,P0237, P0238, P2227, P2228, P2229, P2230 or P2610 is not set.
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The time between current ignition cycle and the last time the engine was running is greater than 10 s.
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The DTCs run continuously when the above conditions have been met.
OR
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•
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DTC P0097, P0098, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0016, P0117, P0118, P0121, P0122, P0123, P0128, P0222, P0223, P0237, P0238, P0335, P0336, P2227, P2228, P2229 or P2230 is not set.
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The engine speed is between 400-6000 RPM.
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The Engine Coolant Temperature (ECT) is between -7-125°C (19.4-257°F).
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The Intake Air Temperature (IAT) is between -20-125°C (-4-257°F).
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The DTCs run continuously when the above conditions have been met.
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P0237 and P0238
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•
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The ignition is ON or the engine is running.
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The DTCs run continuously when the above conditions have been met.
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Conditions for Setting the DTC
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P0236
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•
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The ECM detects that the boost pressure sensor signal is not within range of a model derived from the BARO sensor, the MAP sensor, the throttle intake air pressure sensor, the throttle position sensor and the boost pressure sensor when the engine is running.
OR
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The ECM detects that the boost pressure sensor signal is less than 50 kPa or greater than 115 kPa when the ignition is ON and the engine is NOT rotating.
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P0237
The ECM detects that the boost pressure sensor voltage is less than 0.09 V for greater than 5 s.
P0238
The ECM detects that the boost pressure sensor voltage is greater than 3.9 V for greater than 5 s.
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Action Taken When the DTC Sets
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DTCs P0236, P0237, P0238 are Type B DTCs.
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The ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power.
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Conditions for Clearing the MIL/DTC
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DTCs P0236, P0237, P0238 are Type B DTCs.
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•
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The CAC is connected to the turbocharger and to the throttle body by flexible duct work that requires the use of special high torque fastening clamps. These clamps cannot be substituted. In order to prevent any type of air leak when servicing the ductwork, the tightening specifications and proper positioning of the clamps is critical and must be strictly adhered to.
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Use a solution of dish soap and water in a spray bottle to pinpoint any air leaks.
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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
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Circuit/System Verification
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1.
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Verify that DTC P0641, P0651, P0697, or P06A3 is not set.
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3.
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Ignition ON, observe the scan tool MAP Sensor, Boost Pressure Sensor and BARO Sensor parameters. Compare the parameters to the
Altitude Versus Barometric Pressure
table. The parameters should be within the specified range displayed in the table for the specific altitude.
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4.
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Engine idling, observe the scan tool Boost Pressure Sensor and the BARO Sensor parameters. The parameters should be within 4 kPa.
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5.
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Compare the scan tool MAP Sensor parameter to the Boost Pressure Sensor parameter during a WOT acceleration at the time of the 1-2 shift. The values read off should be within 20 kPa.
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6.
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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.
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1.
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Verify the integrity of the entire air induction and exhaust systems, including all turbocharger components, by inspecting for the following conditions:
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Hairline fractures of the boost pressure sensor housing
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Hairline fractures of the MAP sensor housing
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Loose or improper installation
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An air flow restriction
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Vacuum line restrictions
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An air leak between the turbocharger and the throttle body, including the charge air cooler assembly.
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Verify that an exhaust leak does not exist, including the mating surface area between the turbocharger and the exhaust manifold.
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Verify that restrictions do not exist in the exhaust system. Refer to
Restricted Exhaust
.
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If a condition is found, repair or replace the affected component as necessary.
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2.
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Ignition OFF, disconnect the harness connector at the B65 intake air pressure and temperature sensor.
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3.
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Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 Ω between the low reference circuit terminal 1 or A and ground.
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4.
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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.
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5.
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Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 or C and ground.
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6.
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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 ECM.
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7.
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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 ECM.
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8.
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Verify the scan tool Boost Pressure Sensor parameter is greater than 275 kPa.
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9.
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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.
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10.
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Install a 3 A 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.
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11.
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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.
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12.
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If the circuits test normal, test or replace the B65 intake air pressure and temperature sensor.
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Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
