Going DEF in the Artic Vortex ?

[Stocker Steve]

Minor cold snap here down to -19 F, but as low as -38 a little way north. Indicator alarm came on for Low DEF but gauge said I was fine. Added some warm DEF and gauge went up but alarm stayed on.... Alarm cleared after we had a warmup. Is this a sensor thing or a heater thing or something else?

 

[Silver]

It's likely a cold thing.

 

[callmefence]

I would guess as to that being normal
Def will freeze. Def tanks are designed to freeze and they have a heater. Your def was frozen until the heater thawed it out.

 

[Silver]

It's important to keep your def level well below full during freezing temps. Seems to me the mechanic told me to keep it below 3/4.

 

[chevytaHOE5674]

Correct dont keep the tank full. Early in the DEF days before much was known many a plastic tank split at the seams from freezing.