PACCAR MX (2004 Emissions) Fault Code: P0486 EGR Pressure Difference – Data Erratic, Intermittent, or Incorrect at Ignition On

SET CONDITIONS:
The PCI ECU (D420) detects that measured EGR pressure difference deviates by more than 5 mbar [0.07 psi].

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:
EGR pressure difference sensor deviation

ADDITIONAL INFORMATION:
The EGR pressure difference sensor (F751) is monitored against ambient pressure.