SPN 1761 FMI 1: DEF tank level, below normal, most severe
DEF tank is empty or close to it. Type another SPN and FMI to check it.
DEF tank is empty or close to it. The engine will derate.
- Fill the DEF tank.
- If it's full, check the level sender.
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 1761 FMI 1 means
DEF tank is empty or close to it. The engine will derate.
FMI 1: below normal, most severe
Reading is way too low. Treat it as real until you prove the sensor wrong. (SAE J1939-73: Data valid but below normal operational range, most severe level.)
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.
- If it's full, check the level sender.
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 1761
| Code | What failed | Urgency |
|---|---|---|
| SPN 1761 FMI 3 | voltage high or shorted high | Fix it today |
| SPN 1761 FMI 4 | voltage low or shorted low | Fix it today |
| SPN 1761 FMI 17 | below normal, least severe | Schedule it |
| SPN 1761 FMI 18 | below normal, moderately severe | 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 1761 FMI 1 mean?
DEF tank is empty or close to it. The engine will derate. FMI 1 means: Reading is way too low. Treat it as real until you prove the sensor wrong.
Can I keep running with SPN 1761 FMI 1?
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 1761 FMI 1?
Fill the DEF tank. If it's full, check the level sender.
How do I clear SPN 1761 FMI 1?
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 1761 FMI 1?
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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