Cummins fault code 5941
Machine Constrained Operation- Received Network Data in Error. The received J1939 datalink message was not valid.: network data error
What it means
Cummins' description: Machine Constrained Operation- Received Network Data in Error. The received J1939 datalink message was not valid..
SPN 520968 is Machine Constrained Operation- Received Network Data in Error. The received J1939 datalink message was not valid.. FMI 19 means data received over the vehicle network was flagged as bad by the module that sent it.
The engine ECM talks to the transmission, ABS, dash and aftertreatment modules over the J1939 data network. These codes mean the ECM itself, its calibration, or its communication with other modules has a problem.
What the lamp means
This code normally doesn't turn on a dash lamp. It's logged in the ECM for a technician to see, and often explains another active code.
Green, yellow, red: three ways this can look
The same code can be a quick fix or a reason to shut down. Match your situation to the closest example.
Keep an eye on it
A network timeout logged once, often during cranking, that cleared.
Schedule a repair
Gauges dropping out, the transmission or ABS acting odd, or codes returning. Book diagnosis. These can go from annoying to stranded quickly.
Stop and get help
Red lamp for an ECM internal failure, or the engine won't start or shuts down. Get it towed or seen where it sits.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- ECM calibration doesn't match the vehicle or another module
- ECM internal failure
What you can check before calling
- Note which other systems acted up: gauges, transmission, ABS
- Check for recent electrical work or aftermarket devices plugged into the diagnostic port
- Check batteries and grounds
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.
Engines and sources
Listed by Cummins for: QSB 6.7, QSL 9, QSX 15, QSB 4.5, QSF 3.8, QSG 12. Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Same SPN, other failure types
Related ECM, network and data link codes
- 5133 SPN 2006 FMI 9
Source Address 6: abnormal update rate - 4722 SPN 237 FMI 2
Vehicle Identification Number: erratic or intermittent signal - 4721 SPN 237 FMI 31
Vehicle Identification Number: condition exists - 4517 SPN 237 FMI 13
Vehicle Identification Number: out of calibration - 4437 SPN 1668 FMI 2
J1939 Network #4: erratic or intermittent signal - 3697 SPN 630 FMI 12
ECM Calibration Memory: bad device or component
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does Cummins fault code 5941 mean?
Cummins fault code 5941 is J1939 SPN 520968 FMI 19: Machine Constrained Operation- Received Network Data in Error. The received J1939 datalink message was not valid.. In plain terms: machine constrained operation- received network data in error. the received j1939 datalink message was not valid.: network data error.
Can I keep driving with Cummins code 5941?
Usually, yes. This code doesn't normally turn on a lamp by itself, but check for other active codes that might be more serious. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 5941?
SPN 520968 identifies the part or system (Machine Constrained Operation- Received Network Data in Error. The received J1939 datalink message was not valid.). FMI 19 describes the type of failure: network data error.
What usually causes Cummins code 5941?
The most common causes are: eCM calibration doesn't match the vehicle or another module; eCM internal failure.

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