PACCAR Fault Code P3909: Pump Module Heater – Voltage Too High or Short Circuit to Supply

Code details

Manufacturer

PACCAR (Kenworth & Peterbilt)

Applies to

PACCAR MX-13 (2013–2016)

Fault code

P3909

J1939 SPN

5745

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 P3909 — Heater Element DEF Return Pipe – Voltage Too Low or Short Circuit to Ground on ECU (D442) Pin (25)
• PACCAR Fault Code P3853 — PM Sensor Temperature Probe – Voltage Too Low or Short Circuit to Ground
• PACCAR Fault Code P3910 — Heater Element DEF Inlet Pipe – Voltage Too High or Short Circuit to Supply on ECU (D442) Pin (26)
• PACCAR Fault Code P3853 — Pump Module – Failed to Thaw
• PACCAR Fault Code P3910 — Pump Module Heater – Voltage Too Low or Short Circuit to Ground