Allison Transmission 3500 SP

(A)–Vertical
(B)–Horizontal
(1)–6Position
(2)–3Position
Figure4–2.TypicalAllisonStripPushButtonShiftSelectors
4.1.3SELECTORDISPLAYFLASHING(INHIBITS).Whenappropriate,the
transmissioncontrolsystemautomaticallyinvokesaninhibittoprotectagainst
certaintypesofabusiveoperation,suchas:
•Enginespeedinhibit:preventsshiftfromneutraltoeitheraforward
rangeorreverseiftheenginespeedisabove900rpm.Thisfeatureis
disabledinemergencyvehiclesandsomeothertypesofspecialized
equipment.
Iftheenginespeeddropsbelowtheinhibitspeedwithinaspecied
graceperiodof3-seconds,theinhibitwillself-clearandtherequested
shiftwillbecommanded.Thesame3-secondgraceperiodispermitted
forapplicationswithanenabledNeutralIndicatorforPTOoutput
function.
•Neutral-to-RangeAssist:invehicleswithoptionalNeutral-to-Range
Assistfeature.Enginemanagementcommandsaresentfromthe
transmissioncontrollerwhichwillattempttoreducetheenginespeed
whentheenginespeedisgreaterthanthetransmission'sallowablelimit
andashiftfromN(Neutral)toforwardorreversehasbeenrequested
withtheshiftselector.Theoperatormusthavetheservicebrakes
applied.ThisfeaturemustbespeciedwhentheTCMcalibrationis
dened.
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