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).

Observable symptoms
1) None

Probable cause
1) Connector
2) Wiring harness
3) Open circuit, Ground wire
4) Short circuit to battery voltage, Signal wire
5) Short circuit to 5V, Signal wire
6) Restricted crankcase ventilation
7) Crankcase pressure sensor
8) Engine control module (ECM)
9) Engine damage or wear