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SPN 111 FMI 1 — Coolant level — low
CriticalEngineStop as soon as it's safe
Applies to: Detroit · Paccar · Volvo
Coolant level — low.
Don't risk it — get a diesel tech on the truck.
Look up listed providers near you and give them this SPN/FMI when you call.
How serious is it?
Critical. Stop as soon as it's safe.
Most likely causes
- Coolant leak
- Sensor failure
- Leak
- Sensor
First moves (roadside)
- Check level immediately
- Inspect for leaks
- Verify level
FAQ
What does SPN 111 FMI 1 mean?
Coolant level — low.
How serious is SPN 111 FMI 1?
Critical — Stop as soon as it's safe.
What's the most likely cause of SPN 111 FMI 1?
The most common cause is: Coolant leak. Other possibilities include Sensor failure; Leak; Sensor.
Can I keep driving with SPN 111 FMI 1?
Stop as soon as it's safe. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Throwing this code right now?
Find a mechanic or related guides
General diagnostic guidance for heavy-duty diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack). Not a substitute for a scan-tool diagnosis on your specific truck.