PACCAR MX (2004 Emissions) Fault Code: P1573 Inlet Air Temperature in Inlet Manifold – Data Valid but Too High

SET CONDITIONS:
The PCI ECU (D420) detects that the boost temperature is more than 127?C [261?F] for more than 120 seconds.

DIAGNOSTIC CONDITION:
The diagnostic runs 180 seconds after the engine is started.

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:
1. Contaminated intercooler
2. Faulty engine cooling fan
3. Boost temperature sensor deviation

ADDITIONAL INFORMATION:
The boost temperature is measured in the inlet manifold near cylinder 2 by the boost temperature sensor (F804).