Circuit DescriptionThe crankcase pressure sensor is used to monitor the pressure inside the crankcase. The engine control module (ECM) supplies the crankcase pressure sensor a 5 volt reference voltage. When the crankcase pressure is low, the sensor signal voltage is low. When the crankcase pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the crankcase pressure signal circuit voltage to calculate the pressure of the air within the crankcase.

Component LocationThe crankcase pressure sensor is located near the crankcase ventilation filter.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault CodesThe engine control module (ECM) detected the crankcase pressure in the breather tube was greater than a calibratable value.

Action Taken When the Fault Code is ActiveThe ECM logs the fault code immediately when the diagnostic runs and fails.Conditions for Clearing the Fault CodeTo validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.Use INSITE™ electronic service tool “Data Monitor/Logger” feature to monitor “Crankcase Pressure” with the engine running at idle. If the crankcase pressure reading is below 7.0 in H20, the repair has been validated.The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.

Shop TalkIf this fault code is active, the crankcase breather element may need to be replaced.

Possible Cause:1) Crankcase Pressure sensor failure2) Crankcase breather filter failure3) ECM calibration