PACCAR MX (2004 Emissions) Fault Code: P2275 Water in Fuel – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (A49)

SET CONDITIONS:
This DTC is set when the ECU detects a higher voltage than expected on the signal or control circuit of the ECU.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected. To validate the repair, monitor the water in fuel sensor signal with the diagnostic service tool.

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. The sensor or actuator signal wiring has a short circuit to supply.
2. Faulty water in fuel sensor

ADDITIONAL INFORMATION:
1. The water in fuel sensor is part of the fuel filtration module (L097).
2. The sensor voltage can be monitored with the diagnostic service tool.