PACCAR MX (2004 Emissions) Fault Code: P1404 Crankcase Air Pressure – Data Erratic, Intermittent or Incorrect, at Ignition On

PACCAR MX (2004 Emissions) Fault Code: P1404 Crankcase Air Pressure – Data Erratic, Intermittent or Incorrect, at Ignition On

SET CONDITIONS:
The PCI ECU (D420) detects that the measured crankcase pressure deviates greater than 15 mbar [0.22 psi] from the expected pressure.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on (engine not running).

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Leakage on the crankcase pressure sensor bracket or pipe
2. Blocked crankcase pressure sensor bracket or pipe
3. Engine stalled twice consecutively
4. Crankcase pressure sensor deviation

ADDITIONAL INFORMATION:
The crankcase pressure is monitored with the crankcase pressure sensor (F806) against ambient pressure.