PACCAR (Kenworth & Peterbilt)
PACCAR fault code
SPN 5031 / FMI 10
PACCAR Fault Code P3927: NOx Sensor After Catalyst – Data Valid But Too High
P3927 on PACCAR (Kenworth & Peterbilt) engines means: NOx Sensor After Catalyst – Data Valid But Too High. The failure mode (FMI 10) is “abnormal rate of change”.
Code details
- Manufacturer
- PACCAR (Kenworth & Peterbilt)
- Applies to
- PACCAR MX-13 (2017–2020)
- Fault code
- P3927
- J1939 SPN
- 5031
- FMI
- 10 — Abnormal rate of change
- Truck models in source
- Kenworth T680, T880, W900, T800; Peterbilt 579, 389, 567, 367
What to do next
- Read active and inactive codes with the OEM service tool and note the occurrence count.
- FMI 10 tells the shop the type of failure to test for: abnormal rate of change.
- Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.
Get this code diagnosed
Send one request and nearby diesel shops and mobile mechanics can quote the repair.
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Related fault codes
- PACCAR Fault Code P3927 — Heater Element NOx Sensor After Catalyst Performance – Malfunction
- PACCAR Fault Code P3915 — NOx Sensor After Catalyst – Heating Error
- PACCAR Fault Code P3915 — Heater Element NOx Sensor After Catalyst – Warm-Up Failed
- International Fault Code SPN 5031 FMI 10 — Aftertreatment 1 Outlet NOx Sensor Heater Ratio: Abnormal Rate of Change
- International Fault Code SPN 5031 FMI 2 — Aftertreatment 1 Outlet NOx Sensor Heater Ratio : Data Erratic, Intermittent Or Incorrect
Source: PACCAR MX-13 2017–2020 fault code list (Diesel Laptops). See also OBD-II codes.