PACCAR Fault Code P3947: Exhaust Gas Temperature Sensors SCR – Voltage Too Low or Short Circuit to Ground

Code details

Manufacturer

PACCAR (Kenworth & Peterbilt)

Applies to

PACCAR MX-13 (2013–2016)

Fault code

P3947

J1939 SPN

5743

FMI

4 — Voltage below normal, or shorted to low 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 4 tells the shop the type of failure to test for: voltage below normal, or shorted to low 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 P3872 — PM Sensor – Data Not Rational, Drifted Low
• PACCAR Fault Code P3982 — Exhaust Gas Temperature After DPF or SCR Catalyst – Data Erratic, Intermittent or Incorrect
• PACCAR Fault Code P3988 — Fuel Dosing Valve – Voltage Too High or Short Circuit to Supply
• PACCAR Fault Code P3872 — CAN Communication – Message Timeout from SCR Exhaust Gas Temperature Sensors ECU
• PACCAR Fault Code P3946 — Exhaust Gas Temperature Sensors SCR – Voltage Too High or Short Circuit to Supply
• PACCAR Fault Code P3948 — Exhaust Gas Temperature Sensors SCR – Data Valid But Too High
• PACCAR Fault Code P3949 — CAN – Time-Out from SCR Exhaust Gas Temperature Sensors ECU
• PACCAR Fault Code P3982 — Exhaust Gas Temperature Sensors SCR Power Supply – Interrupted