Case 621G - Page 136

3-CONTROLSANDINSTRUMENTS
ResettingtheSelectiveCatalyticReduction(SCR)system
Afterafailureorwarninghasbeenset,theSCRsystemmustperformautomaticteststodetermineiffailuresor
warningshavebeenresolved.Therearetwocategoriesofsystemwarnings:
1.Electricalfailureswhichonlyneedkeycycletoheal.
2.FailureswhichneedanactiveUreaDosingSystemtoheal:
•HeatedupSCR
•Highenginespeedandtorque
Thesystemmustperformthefollowingactionsinordertorecognizetheresolvedfailuresorwarningsandresetitself.
1.ForDEF/ADBLUE®levelwarnings:
a.KeyswitchmustbecycledOFFthenON.
2.ForpoorDEF/ADBLUE®qualitywarnings:
a.KeyswitchmustbecycledOFFthenON.
3.ForSCRsystemwarnings,oneofthefollowingconditionsmustoccur,dependingontheexactcauseofthewarn-
ing:
a.Requiresthemachinetobeoperatedforapproximately20minataminimumof50%loadtooperatetheSCR
system.
b.Requiresstartingandrunningtheengine,butdoesnotrequiretheSCRsystemtooperate.
c.RequiresthekeyswitchtobecycledOFFthenON.
Validationre-starts
Validationre-startsapplytothescenario“3a”ofSCRsystemwarnings(seelistabove).Validationre-startsallow
operationofthemachineforupto30minwithoutpowerlossafterapoorDEF/ADBLUE®qualityorSCRsystemfault
hasbeendetected.Uptothreere-startsarepermitted.Re-startsarecountedifeitherofthefollowingconditionsare
met:
1.Keyoff,wait2minforECUafter-run.
2.Keyon,wait5–15s
3.Keyoff,wait5–15s
4.Keyon,wait5–15s
5.Start
Normaloperationwillresumeifaresetisdetectedwithinthe30minwindow.
Ifaresetisnotdetectedwithin30min,powerlosswilloccurasdescribedinthetableabove.
Validationre-startsarenotavailable7minbeforesevereinducement,orifinducementisactivatedasecondtime
within40h(inducementsfromlowtanklevelarenotconsideredtowardvalidationrestartavailability)
Ifallthreevalidationre-startshavebeenusedandthesystemhasnotbeenreset,seeyourlocalauthorizeddealer
forrepair.
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