DISCOVERY
ETMąB5
CIRCUIT OPERATION
Speed Input
WiththeCruiseControlSwitch(X115)on,voltage
fromFuseF18isappliedtotheCruiseControl
ECU(Z121),CruiseControlVacuumPump
(M103),SteeringWheelCruiseSwitches(X266)
throughtheWYwire,RotaryCoupler(Z104)and
PBwire.TheCruiseControlECU(Z121)is
groundedatterminal8throughtheBwireto
E201.
Terminal11oftheCruiseControlECU(Z121)
monitorstheVehicleSpeedoutputsignalfromthe
InstrumentCluster(Z142)throughtheYKwire.
Thissignalisapulsingvoltageanditsfrequency
changeswithvehiclespeed.
System Disable
TheCruiseControlSystemcanbedisabledinone
offourways:
Cruise ControlVacuum Pump (M103)
1.
TheCruiseControlSwitch(X115)isputinthe
0position,removingpowerfromtheCruise
WiththeCruiseControlSwitch(X115)on,voltage
isappliedtotheCruiseControlVacuumPump
(M103)throughtheWUwire.Whenacruise
speedisset,theCruiseControlECU(Z121)
appliesgroundthroughtheBRwiretooperatethe
pumpmotorandappliesgroundthroughtheBY
wiretoclosethenormallyopensolenoidvalvein
thepump. Thepumpappliesvacuumtothe
actuator.
ControlECU(Z121)andvacuumpump,and
erasingthesetspeedmemory.
2.
TheRES/DECELSwitchisdepressed,
signallingtheCruiseControlECU(Z121)to
disengagethesystem.
3. Thebrakepedalisdepressedandavacuum
valveintheBrakeSwitchVentValveopens
(X112). Thisventsvacuumtotheactuator
valveandreleasesthethrottle.
SET/ACCEL
Tosetacruisespeed,theCruiseControlSwitch
(X115)mustbeonandvehiclespeedmust
exceed28mph(45km/h).WhentheSET/ACCEL
Switchisdepressedundertheseconditions,
voltagefromFuseF18isappliedtoterminal3of
theCruiseControlECU(Z121)throughtheclosed
CruiseControlSwitch(X115)andSteeringWheel
CruiseSwitches(X266),causingthevacuum
pumptooperate.WhentheSET/ACCELSwitchis
released,voltageisremovedfromterminal3,
signallingtheECUtosetthespeed.
RES/DECEL
WhentheRES/DECELSwitchisdepressed,
voltageisappliedtoterminal4oftheCruise
ControlECU(Z121).ThisvoltagesignalstheECU
todisengagethesystemandthevehicleslows
down.Whentheswitchisdepressedasecond
time,voltageisagainappliedtotheECUandthe
vehiclereturnstothepreviouslysetspeed.
EĂLĂEĂCĂTĂRĂIĂCĂAĂLąTĂRĂOĂUĂBĂLĂEĂSĂHĂOĂOĂTĂIĂNĂGąMĂAĂNĂUĂAĂL
1
| Categories | Land Rover, Land Rover Discovery |
|---|---|
| Tags | Land Rover |
| Model Year | 1995 |
| Download File |
|
| Document Type | Electrical Troubleshooting Manual |
| Language | English |
| Product Name | Discovery |
| Product Brand | Land Rover |
| Document File Type | |
| Publisher | landrover.com |
| Wikipedia's Page | http://en.wikipedia.org/wiki/Land_Rover |
| Copyright | Attribution Non-commercial |
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