Navistar International LT Series - DEF Tank; Low DEF Level

Operation
DEFTank
TheDEFtankislocatedonthedriver-sideofthevehicle,forward
ofthefueltankandbehindthebatterybox.Forreference,see
sectionModelDescription>ExteriorComponents.
ThellerneckinletonaDEFtankhasaBLUEcapandhasa
smallerdiameter(19mm)thanthatofallerneckonthediesel
fueltank.
TheSCRsystemisdesignedtooperatenormallyalsounder
freezingconditionswhilecontainingDEF.ThoughDEFfreezes
atapproximately10°F(-12°C),nooperatorinteractionis
necessarywhenoperatingincoldtemperatures.
Undercoldorverydryconditions,watervaporcanbeseen
comingfromthevehicletailpipe.Thisisnormalsystem
operation.Thewatervaporwilldisappearwithinafewminutes
ofnormalvehicleoperation.
AfterthekeyisturnedOFFonavehiclewithSCRsystem,a
pumpingsoundmaybeheardfromunderneaththevehicle.The
soundismadebytheaftertreatmentDEFdosingunitwhileit
purgesanyunusedDEFfromthesystemandreturnsittothe
DEFtank.Thisisnormalsystemoperation.Ittakesabout60
secondstocomplete.
CAUTION
Topreventvehicle/propertydamage,after
turningthekeyOFFonavehiclewithSelective
CatalystReduction(SCR)system,donot
disconnectthevehiclebatterieswhileyou
canhearapumpingsoundfromunderneath
thevehicle.Thesoundmaylastforabout60
seconds.
LowDEFLevel
WARNING
Topreventpersonalinjuryand/ordeath,or
damagetoproperty,maintaintheadequateDiesel
ExhaustFluid(DEF)leveltoavoidalossof
enginepowerandvehiclespeed.
Ontheinstrumentpanel,youcanmonitortheuidlevelusingthe
DEFLevelGauge.YouwillseeadditionalwarningsiftheDEF
istoolow.IfDEFleveldecreasesto2.5%orlower,theengine
performancewillstarttobederatedbyatleast25%;iftheDEF
levelremains0%foranextendedtime,thevehiclespeedwill
belimitedto5mph(8km/h).RelltheDEFtankwithapproved
DEFatanypoint,andthevehiclewillresumenormaloperation.
Seethefollowingtableforadetailedexplanationofindicators
aboutlowDEFlevel.
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