SPN 4096: NOx high: DEF tank empty
NOx is over the limit because the DEF tank ran dry. Type another SPN and FMI to check it.
NOx is over the limit because the DEF tank ran dry. This leads to a derate.
- Fill the DEF tank.
- The derate clears once dosing resumes.
Paste the whole line if you like: "SPN 3251 FMI 0", "3251/0" or Deere's "003251.00". Plain-words guidance; the service manual wins.
What SPN 4096 means
NOx is over the limit because the DEF tank ran dry. This leads to a derate.
How urgent it is
Fix it today. Fix it this shift or today. Left alone it tends to become a derate.
What to check first
- Fill the DEF tank.
- The derate clears once dosing resumes.
Plain-words guidance for a foreman, not a repair procedure. Makers add their own codes and steps; the machine's service manual wins.
Other FMIs for SPN 4096
| Code | What failed | Urgency |
|---|---|---|
| SPN 4096 FMI 31 | condition exists | Fix it today |
Next time, Dozer catches the code when it fires.
Plug a CAN logger into the machine's J1939 port, or connect the telematics you have. When a code fires, Dozer opens a repair ticket with the meaning, how urgent it is and what to check.
- The code, the machine and its hours on one ticket
- Severity sorted: keep working, plan a stop, or stop now
- The mechanic gets the checklist before they drive out
- Repeat codes on the same machine get flagged
LIVE EX-04 · SPN 3251 FMI 0 · plan a stop today Photo is an AI-generated stand-in, not a customer site.
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Questions crews ask
What does SPN 4096 mean?
NOx is over the limit because the DEF tank ran dry. This leads to a derate.
Can I keep running with SPN 4096?
Fix it today. Finish what's safe to finish, then fix it this shift. Ignoring it usually turns into a derate or a bigger repair. If the machine derates or the stop lamp is on, stop.
What should I check first for SPN 4096?
Fill the DEF tank. The derate clears once dosing resumes.
How do I clear SPN 4096?
Fix the cause first. Most codes go inactive by themselves once the condition is gone and the engine has run a key cycle or two. Clearing it with a service tool without a fix only hides it until it comes back.
Which machines show SPN 4096?
Any diesel that speaks SAE J1939: excavators, dozers, loaders, haul trucks, generators and on-road trucks with Cat, Cummins, Deere, Komatsu, Volvo, Kubota, Perkins and other engines. The SPN means the same thing on all of them; the fix steps can differ, so check the service manual.
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