Cummins
Cummins fault code
SPN 639 / FMI 2
Cummins Fault Code 426: SAE J1939 datalink - cannot transmit
426 on Cummins engines means: SAE J1939 datalink - cannot transmit. The failure mode (FMI 2) is “data erratic, intermittent or incorrect”.
Lamp: Yellow
Engine may continue to run, but must be repaired the same day.
Code details
- Manufacturer
- Cummins
- Applies to
- Cummins QS-series electronic engines
- Fault code
- 426
- J1939 SPN
- 639
- FMI
- 2 — Data erratic, intermittent or incorrect
- J1587 PID / SID
- S231
- Engine models
- QSK19, QSK23
- QSK45/60/78 severity level
- QSK45: 3 • QSK60: 3 • QSK78: 3
What to do next
- Read active and inactive codes with the OEM service tool and note the occurrence count.
- FMI 2 tells the shop the type of failure to test for: data erratic, intermittent or incorrect.
- 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
- Cummins Fault Code 426 — SAE J1939 datalink - cannot transmit
- Cummins Fault Code 426 — SAE J1939 datalink - cannot transmit
- Cummins Fault Code 185 — Engine Control Module Network Communication Error
- Cummins Fault Code 285 — SAE J1939 Multiplexing PGN Timeout Error
- Cummins Fault Code 286 — SAE J1939 Multiplexing Configuration Error
- Cummins Fault Code 427 — SAE J1939 not fast enough
- International SA 28 SPN 639 FMI 9 — J1939 Communication Link Fault
- International SA 33 SPN 639 FMI 9 — J1939 Drivetrain Data Link Lost
Source: Cummins "Diagnostic Fault Codes For Cummins Engines", publication 80-1044 Rev 5/2013, page 12. See also OBD-II codes.