P04DB - Crankcase Ventilation System Disconnected

When Monitored:

Engine at operating temperature, driving at a steady speed. This monitor takes 10 minutes to completely run.

Set Condition:

Crankcase Pressure readings have been significantly elevated, as compared to historic trends saved in the Powertrain Control Module.

Possible Causes

DISCONNECTED CRANKCASE VENTILATION HOSE
INTAKE SYSTEM LEAK
CRANKCASE BREATHER FILTER CLOGGED
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

1. CHECK THE CRANKCASE VENTILATION HOSE

NOTE: If there are any DTCs present for the EGR Valve, EGR Airflow Control Valve, or any of the pressure sensors, perform the diagnostics for those DTCs before proceeding with this test procedure.

1. Visually inspect the Crankcase Ventilation Hose. Is the hose disconnected, cracked, pinched or damaged?

Yes
• Repair or replace the Crankcase Ventilation Hose in accordance with the service information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Go To 2

2. CHECK THE INTAKE SYSTEM FOR LEAKS

1. Perform the INTAKE AIR SYSTEM PRESSURE TEST diagnostic procedure. (Refer to 29 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing) .

Were any Intake System leaks found?

Yes
• Perform the appropriate repair.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Replace the Crankcase Breather Filter in accordance with the service information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).