2010 Cadillac Truck SRX FWD V6-3.0L Page 1325
DTC P0238
- Turbocharger Boost Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit Description
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
