Mack V-MAC IV - Idle Management Features

64V-MACCo-PilotOperator'sManual
LowIdleAdjustment
Note:Onchassisequippedwithanautomatictransmission,thespeedcontrol
switchescannotbeusedtoadjustenginelowidlespeed.Attemptingtosetlowidle
inthismannerwillcausethevehicleelectroniccontrolunit(VECU)toenterthe
reprogrammingmoderesultingintheidlespeeddroppingto550RPM(650RPMfor
non-catalyzedexhaustaftertreatmentsystem),butitwillnotbepossibletosetanew
idlespeed.Ifthereprogrammingmodeisentered,simplyturnthespeedcontrolswitch
OFF,andidlespeedwillreturntotheoriginallysetspeed.Resettinglowidlespeedon
achassisequippedwithanautomatictransmissionrequiresascantoolrunningthe
VCADSsoftware.ConsulttheVCADSUser'sGuideforadditionalinformation.
ThissectionexplainstheproceduretoresetthelowidlespeedusingtheSpeed
Controlswitches.
Thevehiclemanagementandcontrol(V-MAC)IVsystemallowsthelowidletobe
setwithintherangeof550to700RPM(650–700RPMfornon-catalyzedexhaust
aftertreatmentsystem).Thisprovidesexibilitytosetthelowidletothesmoothest
enginespeedforthevehicle.
Therearetwostepsrequiredtoresetthelowidlespeed.Therststepplacesthe
vehiclemanagementandcontrol(V-MAC)IVsystemintothelow-idleadjustmode.
Inthismode,vehiclemanagementandcontrol(V-MAC)IVisreadytoacceptthe
newidlespeed.
Thesecondstepistoactuallytellvehiclemanagementandcontrol(V-MAC)IV
whatthenewidlespeedwillbe.
Therstphaseintheprocessismeetingtherequirementslistedbelow.
1Thevehiclemanagementandcontrol(V-MAC)IVsystemmusthavetheLow-Idle
Adjustoptionenabledinthecustomerdataspace.Thisfunctioncanbedisabled
bythecustomer.
2Besuretherearenoactivefaultsinthesystem.
3Thevehiclemustbestationary.
4Theparkingbrakemustbeapplied.
5Theacceleratorpedal(AP)mustbeattheidleposition(notpressed).
6TheSpeedControlON/OFFswitchmustbeturnedONandOFF3timeswithin
twoseconds.Atthispoint,theidlespeedwilldropto550RPM,andvehicle
managementandcontrol(V-MAC)IVwillnowbereadytoacceptanewspeed.
BesuretoleavetheignitionkeyintheONposition.
https://truckmanualshub.com/