SPN 4376 FMI 6: DEF return valve, current high or grounded
DEF return valve circuit: current above normal or grounded circuit. Type another SPN and FMI to check it.
DEF return valve circuit: current above normal or grounded circuit. An electrical fault (usually a wire shorted to ground or a shorted coil), not a reading out of range.
- Look at the plug and harness at the DEF return valve for rubbed, pinched, wet or green pins.
- Check supply voltage and ground at the plug (or the coil resistance on a valve or heater).
- If the wiring is good, replace the part.
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 4376 FMI 6 means
DEF return valve circuit: current above normal or grounded circuit. An electrical fault (usually a wire shorted to ground or a shorted coil), not a reading out of range.
FMI 6: current high or grounded
Too much current. Usually a wire shorted to ground or a shorted coil. (SAE J1939-73: Current above normal or grounded circuit.)
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
- Look at the plug and harness at the DEF return valve for rubbed, pinched, wet or green pins.
- Check supply voltage and ground at the plug (or the coil resistance on a valve or heater).
- If the wiring is good, replace the part.
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 4376
| Code | What failed | Urgency |
|---|---|---|
| SPN 4376 FMI 5 | current low or open circuit | 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 4376 FMI 6 mean?
DEF return valve circuit: current above normal or grounded circuit. An electrical fault (usually a wire shorted to ground or a shorted coil), not a reading out of range. FMI 6 means: Too much current. Usually a wire shorted to ground or a shorted coil.
Can I keep running with SPN 4376 FMI 6?
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 4376 FMI 6?
Look at the plug and harness at the DEF return valve for rubbed, pinched, wet or green pins. Check supply voltage and ground at the plug (or the coil resistance on a valve or heater). If the wiring is good, replace the part.
How do I clear SPN 4376 FMI 6?
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 4376 FMI 6?
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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