PACCAR MX (2004 Emissions) Fault Code: U1853 EGR Valve Module Software Verification – Incorrect

PACCAR MX (2004 Emissions) Fault Code: U1853 EGR Valve Module Software Verification – Incorrect

SET CONDITIONS:
The PCI ECU detects that no or an incorrect calibration verification number (CVN) is received from the EGR valve module.

DIAGNOSTIC CONDITION:
This diagnostic runs once when the ignition is keyed on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition is keyed off for at least 15 seconds and keyed on again, and 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. No or intermittent CAN communication with the EGR valve module. Check:
– EGR valve module power supply
– E-CAN communication
2. Incorrect type of EGR valve module installed
3. Faulty EGR valve module

ADDITIONAL INFORMATION:
When the ignition is keyed on, the PCI ECU (D420) queries the EGR valve module (L095) for a calibration verification number (CVN).

CVN is the calibration verification number and is the result of a check performed on the software values stored in emission-related ECUs (OBD legislation).