The Crankcase Pressure Sensor is used to detect crankcase pressure system failures. The sensor consists of a pressure sensitive diaphragm and amplifier. Crankcase pressure causes the sensor’s diaphragm to deflect and produce an electrical signal proportional to the pressure. The diaphragm deflection signal is amplified in the sensor.
The engine control module (ECM) will set a diagnostic trouble code (DTC) if the sensor signal is not within predetermined limits. The ECM can also disable the engine brake, derate or shut down the engine to avoid engine damage.
The sensor’s signal is monitored by the Engine Control Module (ECM).

Conditions for diagnostic trouble code (DTC):
1) Irrational pressure

Observable symptoms
1) None

Probable cause
1) Crankcase pressure sensor
2) The following connectors may have been switched: B54: Crankcase pressure sensor, B118: Engine oil pressure (EOP) sensor
3) Detailed information
4) Incorrect signal compared to barometric pressure (BARO)