Allison Transmission T 375

controloverretarderoperationandincludevarioustypesofretarderoperator
andvehicleinterfacecontrols.Someoftheavailableoperatorcontrols,known
alsoasRetarderModulationRequest(RMR)devicesinclude:
•Footpedal
•Handlever
•Automaticapplyatclosedthrottle
•Applyintegratedwithservicebrakes
•One-step,two-steporthree-stepapplies
RefertoTable4–7forthevarioustypesofretardercontrolsavailable.
Theretarderapplysystemdoesnotactuatetheretarderdirectly.The
driverusestheretarderoperatorcontrolstorequestadesiredlevelof
retardation,rangingfromnone,uptothemaximumavailablefromthespecic
retarder/transmissioncongurationinuse.TheTCMprocessestherequestin
conjunctionwithotherinputdatawhichdenesthecurrentoperatingstatusof
thetransmissionandvehicle.TheTCMturnstheretarderonattherequested
levelwhenconditionsareappropriateforretarderoperation.
Referto4.3USINGTHEHYDRAULICRETARDERforadditionalinformation
abouttheretardercontrols,retarderperformance,andretarderusage.
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