PACCAR MX (2004 Emissions) Fault Code: P2457 EGR Temperature – Data Valid but Too High, Most Severe

SET CONDITIONS:
The PCI ECU (D420) detects that measured EGR temperature is more than 240°C [464°F] for more than 30 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is keyed on and when the engine is 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?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Coolant level too low
2. Reduced coolant flow, EGR cooler
3. EGR temperature sensor deviation

ADDITIONAL INFORMATION:
The EGR gas flow temperature is monitored by the EGR temperature sensor (F749).