What Does Refill Def Mean?

: to fill again : replenish. intransitive verb. : to become filled again.

What happens if you run out of DEF fluid?

If the truck is allowed to run out of DEF the engine's power is reduced, a solid red warning will be displayed and the vehicle speed will be limited to 5 mph until the DEF tank is refilled.

What happens if I dont refill DEF?

If the reservoir is not replenished with DEF and runs low, vehicle speed will be limited, but as soon as DEF is added, the engine will resume normal speed levels. A prudent measure would be to have a top-off gallon jug of DEF available on each piece of equipment with an EPA 2010 engine with an aftertreatment system.