2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1180

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1180

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:

* Engine speed

* Throttle opening

* Turbocharger boost pressure

* Intake air temperature (IAT)

* Barometric pressure (BARO)

* 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 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 (35 psi). The least

amount of pressure that occurs is when the vehicle is idling or decelerating, and it is equal to the BARO.

Conditions for Running the DTC

P0236

* DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0237, P0238, P2227, P2228, or P2229 are not set.

* The engine is running.

* The engine speed is less than 1,120 RPM.

* The Throttle Position Sensor parameter is less than 10%.

* This DTC runs continuously within the enabling conditions.

P0237

* The engine is running.

* This DTC runs continuously within the enabling conditions.

P0238

* The engine is running.

* This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC

P0236

* The ECM detects that the boost pressure sensor signal plus a calibrated threshold is less than the BARO sensor signal plus a calibrated

threshold.

OR

* The ECM detects that the boost pressure sensor signal plus a calibrated threshold greater than the BARO sensor signal plus a calibrated

threshold.

P0237

The ECM detects that the boost pressure sensor voltage is less than 0.45 V or the measured pressure is less than 50 kPa (7.3 psi).

P0238

The ECM detects that the boost pressure sensor voltage is greater than 4.65 V or the measured pressure is greater than 300 kPa (43.5 psi).

Action Taken When the DTC Sets

DTCs P0236, P0237, P0238, are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0236, P0237, P0238, are Type B DTCs.

Diagnostic Aids

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

* The BARO sensor is integrated within the ECM, and it has a port on the housing that allows it to sense the ambient pressure. Any restriction

at this opening may hinder the operation of the BARO sensor.

Reference Information

Schematic Reference

Engine Controls Schematics (LAU) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics

(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference