PACCAR MX (2004 Emissions) Fault Code: P1168 Fuel Temperature – Data Valid but Too High, Moderately Severe

PACCAR MX (2004 Emissions) Fault Code: P1168 Fuel Temperature – Data Valid but Too High, Moderately Severe

SET CONDITIONS:
The PCI ECU (D420) detects that the fuel temperature is above 95?C [203?F] for more than 300 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine has been running for more than 200 seconds.

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. Restriction in the fuel to tank return circuit or faulty fuel pressure regulating valve.
2. Excessive dumping of fuel from the common rail through common rail pressure release valve (L094).

ADDITIONAL INFORMATION:
1. The low-pressure fuel temperature is measured by the fuel temperature sensor (F803).
2. Engine torque is reduced when this DTC is active.