PACCAR (Kenworth & Peterbilt)
PACCAR fault code
SPN 3605 / FMI 3
PACCAR Fault Code P2604: Coolant Pump – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C1)
P2604 on PACCAR (Kenworth & Peterbilt) engines means: Coolant Pump – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C1). The failure mode (FMI 3) is “voltage above normal, or shorted to high source”.
Code details
- Manufacturer
- PACCAR (Kenworth & Peterbilt)
- Applies to
- PACCAR MX-13 (2017–2020)
- Fault code
- P2604
- J1939 SPN
- 3605
- 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.
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 P2600 — Coolant Pump – Open Circuit on ECU (D420) Pin (C1)
- PACCAR Fault Code P2605 — Coolant Pump – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (C1)
- PACCAR Fault Code P2603 — Coolant Pump Speed – Data Valid But Too High
- International Fault Code SPN 3605 FMI 3 — Engine Coolant Pump Control: Voltage Above Normal, Or Shorted To High Source
- International Fault Code SPN 3605 FMI 4 — Engine Coolant Pump Control: Voltage Below Normal, Or Shorted To Low Source
- International Fault Code SPN 3605 FMI 5 — Engine Coolant Pump Control: Current Below Normal Or Open Circuit
Source: PACCAR MX-13 2017–2020 fault code list (Diesel Laptops). See also OBD-II codes.