Allison Transmission T 270 User Manual

agsaDiagnosticTroubleCode(DTC)asactive,theTCMmaytakea
combinationofdiagnosticresponsesaslistedinthetablebelow.Referto
Table6–1.
Table6–1.DTCResponse
Categoryof
Response
ActionsTaken
Releaselockup(LU)clutchandinhibitLUoperation
Inhibitshiftsfromthecurrentattainedrange
TurnontheCHECKTRANSlight
DisplaythecurrentattainedrangeintheMONITORwindowof
theshiftselector
BlanktheSELECTwindowoftheshiftselector
DoNotShift
(DNS)
Disableabilityforshiftselectorstorespondtoanyrange
changerequestfromtheoperatorusingtheshiftselector(s).
SolenoidsOFF
(SOLOFF)
Allsolenoidsarecommandedoffresultinginhydraulicdefault
operationofthetransmission-PCS1andPCS2areon
hydraulicallywhenoffelectrically.
Returnto
PreviousRange
(RPR)
WhenspeedsensorratioorPS1testsdonotpass,theTCM
commandsthesamerangeascommandedbeforetheshift.
NeutralNo
Clutches(NNC)
WhencertainspeedsensorratioorPS1testsdonotpass,the
TCMcommandsaneutralconditionwithnoclutchesapplied.
DoNotAdapt
(DNA)
TheTCMstopsadaptiveshiftcontrolwhilethecodeisactive.
6.2.1CHECKTRANSLIGHT .Eachtimetheengineisstarted,theCHECK
TRANSlightilluminatesbrieyforabulbcheck.Afterafewsecondsitshould
turnoff.IftheCHECKTRANSlightdoesnotilluminatebrieyaftertheignition
isturnedon,oriftheCHECKTRANSlightremainssteadilyonafterignition
andenginestart,havethevehicleandtransmissionsystemcheckedbya
qualiedAllisonTransmissiontechnician.
IftheCHECKTRANSlightissteadilyilluminatedduetoanactiveDTC,the
shiftselectorblankstheSELECTandonlyshowsarangethetransmission
haslockedintointheMONITORwindowoftheselector,seekimmediate
attentionfromaqualiedAllisonTransmissiontechnician.Performservice
assoonaspossibleinordertominimizethepotentialfordamagetothe
transmissionorvehicle.Thetransmissioncanbeoperatedforashorttime
inthecurrentattainedrangeinordertogetthevehicletoasafelocation
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Allison Transmission T 270 Specifications

General

Brand	Allison Transmission
Model	T 270
Category	Controller
Language	English