PACCAR Fault Code P3864: NOx Sensor Before Catalyst – Short Circuit or Open Circuit

Code details

Manufacturer

PACCAR (Kenworth & Peterbilt)

Applies to

PACCAR MX-13 (2013–2016)

Fault code

P3864

J1939 SPN

3216

FMI

3 — Voltage above normal, or shorted to high source

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 3 tells the shop the type of failure to test for: voltage above normal, or shorted to high source.
• Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.

Related fault codes

• PACCAR Fault Code P170C — NOx Sensor Before Catalyst – Data Erratic, Intermittent or Incorrect, During Overrun
• PACCAR Fault Code P170E — NOx Sensor Before Catalyst Response – Too High
• PACCAR Fault Code P170F — NOx Sensor Before Catalyst – Data Erratic, Intermittent or Incorrect, During Overrun
• PACCAR Fault Code P1710 — NOx Concentration Before Catalyst – Data Valid But Too Low
• PACCAR Fault Code P1711 — NOx Concentration Before Catalyst – Data Valid But Too High
• PACCAR Fault Code P3865 — DEF Tank Temperature Sensor – Internal Error
• PACCAR Fault Code P3869 — PM Sensor – Voltage Too Low or Short Circuit to Ground
• PACCAR Fault Code P3870 — PM Sensor – Current Too High