PACCAR MX (2004 Emissions) Fault Code: P1710 NOx Concentration Before Catalyst – Data Valid but Too Low

PACCAR MX (2004 Emissions) Fault Code: P1710 NOx Concentration Before Catalyst – Data Valid but Too Low

SET CONDITIONS:
The PCI ECU (D420) detects that measured engine NOx emissions are lower than the expected engine NOx emissions for more than 40 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs:
1. When the engine is running at a steady load and its speed is between 1050 and 1850 rpm and
2. When the coolant temperature is above 50°C [122°F] and
3. The engine mode is SCR high efficiency or standard or protection and
4. The NOx sensor before catalyst (F844) is in operating mode

CORRESPONDING OBD READINESS MONITOR:
Exhaust gas sensors monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Humidity sensor deviation
2. NOx sensor before catalyst deviation

ADDITIONAL INFORMATION:
1. The measured engine NOx emission is compared with the expected engine NOx emission.
2. The engine NOx emissions are measured by the NOx sensor before catalyst (F844).