Mack V-MAC IV - Engine Brake; Accessory Relay Control

V-MACCo-PilotOperator'sManual61
EngineBrake
W2076080
Figure26—EngineBrakeSwitch
Toactivatetheenginebrake,movetheenginebrakeswitchtothe1stor2ndON
position.The1stpositionactivatestheenginebrakeunitfor50%power.The2nd
positionprovides100%power.Theenginebrakeswitchcanbeineither1stor2nd
ONpositionduringspeedcontroloperations,butthebrakewillfunctiononlyifno
fuelisrequestedbyvehiclemanagementandcontrol(V-MAC)IVandenginespeed
(RPM)isgreaterthan900RPM.Todisengagethebrake,movetheswitchtotheOFF
position,orpresstheacceleratorpedal(AP).
Note:Theenginebrakewillnotengage
untiltheengineoiltemperature(EOT)has
reached52°C(125°F).
ACCESSORYRELAYCONTROL
Afteranidleshutdown,vehiclemanagementandcontrol(V-MAC)IVwilldeactivate
alltheignitionpowerbusrelays,buttheenginecontrolmodule(ECM)powerrelay
willremainactiveinordertoreducecurrentdrawfromthebatteryaftertheengine
hasstopped.
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