Land Rover Discovery 99my To 03my Electrical Library 3rd Edition Rover Manual

							DESCRIPTION AND OPERATION
4.10DISCOVERY SERIES II
CDL motor operation
The electronic relays in the passenger compartment fusebox supply power feeds or earth 
paths for each door lock motor as necessary. Each door lock motor is connected to the 
passenger compartment fusebox as follows:
Front LH/RH (drivers) door lock motor: 
zA KR wire is connected from the fusebox to the LH/RH front CDL motor.
zA KP wire is connected from the fusebox, via header C0292 LHD/C0291 RHD, to the 
LH/RH front superlock motor and the LH/RH front CDL motor.
zA KS wire is connected from the fusebox, via header C0292 LHD/C0285 RHD, to the 
LH/RH front superlock motor.
Front LH/RH (Passenger) door lock motor:
zA KR wire is connected from the fusebox, via header C0292 LHD/C0290 RHD, to the 
LH/RH front CDL motor.
zA KP wire is connected from the fusebox, via header C0292 LHD/C0291 RHD, to the 
LH/RH front superlock motor and the LH/RH front CDL motor.
zA KS wire is connected from the fusebox, via header C0292 LHD/C0285 RHD, to the 
LH/RH front superlock motor.
LH rear passenger door lock motor:
zA KR wire is connected from the fusebox, via header C0292 LHD/C0290 RHD, and 
header C0761, to the LH rear CDL motor.
zA KP wire is connected from the fusebox, via header C0292 LHD/C0291 RHD, to the 
LH rear superlock motor and the LH rear CDL motor.
zA KS wire is connected from the fusebox, via header C0292 LHD/C0285 RHD, to the 
LH rear superlock motor.
RH rear passenger door lock motor:
zA KR wire is connected from the fusebox, via header C0292 LHD/C0290 RHD and 
header C0761, to the RH rear CDL motor.
zA KP wire is connected from the fusebox, via header C0292 LHD/C0291 RHD to the 
RH rear CDL motor and the RH rear superlock motor.
zA KS wire is connected from the fusebox, via header C0292 LHD/C0285 RHD, to the 
RH rear superlock motor.
Tail door lock motor:
zA KR wire is connected from the fusebox, via header C0292 LHD/C0290 RHD, to the 
tail door CDL motor.
zA KP wire is connected from the fusebox, via header C0292 LHD/C0291 RHD, to the 
tail door CDL motor and the tail door superlock motor.
zA KS wire is connected from the fusebox, via header C0292 LHD/C0285 RHD, to the 
tail door superlock motor. 
						

							DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.11
WINDOWS - FRONT
DESCRIPTION
Windows - Front Description
The front windows are electrically operated from two rocker switches located in the centre 
console. The front windows are controlled by the Body Control Unit (BCU) which limits the 
operation of the windows to when the ignition is in position II and for a period of 44 seconds 
after the ignition is switched off or after the driver’s door is opened. The front window 
operation is suspended when the ignition switch is in the crank position III.
The front windows are powered by electric motors located in each front door. The window 
up/down functions are controlled by reversing the polarity to the motors. The BCU logic 
circuits have a stall detect function that monitors the current drawn by the window motor. 
When the window contacts the top of the door frame or an obstruction the current drawn by 
the electric motor rises. If the BCU detects a sudden current rise the internal logic will 
remove the power supply to the front window motor.
The front windows have a one shot down function which operates if the switch is pressed for 
less than 0.4 seconds. Operation of the switch for more than 0.4 seconds operates the 
windows in inch down mode. The windows stop when the switch is released.
The front windows only operate in the inch up mode for as long as the switch is pressed. The 
windows stop when the switch is released.
Fault conditions related to the front windows can be retrieved from the BCU via the 
diagnostic socket using TestBook/T4.
OPERATION
Windows - Front Supply
Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine 
compartment fusebox where it passes through fusible links 1, 5 and 8 and fuse 13. Fusible 
links 1 and 5 are connected in series.
A feed from fusible links 1 and 5 is connected from the fusebox on an NW wire to the 
passenger compartment fusebox, where it passes through fuse 34. From fuse 34, the feed 
is connected to pin C0664-7 of the BCU on an NG wire. This feed provides the power for the 
window lift motors.
A feed from fuse 13 is connected from the fusebox on a PN wire to pin C0660-13 of the BCU. 
This feed is the permanent battery supply fo the BCU.
A feed from fusible link 8 is connected on an NW wire to the passenger compartment 
fusebox and from the fusebox to the ignition switch on an N wire. 
						

							DESCRIPTION AND OPERATION
4.12DISCOVERY SERIES II
Ignition switch supply
With the ignition switch in position II, the feed from fusible link 8 passes through the ignition 
switch to fuse 29 in the passenger compartment fusebox on a Y wire. From fuse 29 the feed 
is connected to pin C0660-1 of the BCU on a GU wire.
Windows - Front Operation
BCU earth connection
The BCU is earthed from pin C0660-11 on a B wire to earth header C0551.
Front left window up
The left window switch up contact is connected to pin C0660-18 on the BCU by a BS wire. 
When the switch is set to the up position an internal supply from the BCU flows along the BS 
wire through the contacts of the switch and to earth via earth header C0552 on a B wire.
The BCU internal logic monitors the current flow from pin C0660-18 and uses this input as 
an up signal. The BCU routes power from the permanent feed from pin C0664-7 to pin 
C0664-4. From pin C0664-4, the power flows to connector interface C0463-6/C0744-6 on 
an SB wire, and from the connector interface to the LH front window motor on a SU wire. 
The motor is energised and drives the window mechanism towards the up position.
The front left window motor is earthed via an SK wire to connector interface C0744-7/C0463-
7, and an SR wire from the connector interface to pin C0664-1 on the BCU. The BCU 
completes the earth via pin C0664-5 on a B wire to earth header C0018 LHD/C0017 RHD.
Front left window down
The left window switch down contact is connected to pin C0662-1 on the BCU by a BR wire. 
When the switch is set to the down position an internal supply from the BCU flows along the 
BR wire through the contacts of the switch and to earth via earth header C0552 on a B wire.
The BCU internal logic monitors the current flow from pin C0662-1 and uses this input as a 
down signal. The BCU routes power from the permanent feed from pin C0664-7 to pin 
C0664-1. From pin C0664-1, the power flows to connector interface C0463-7/C0744-7 on 
an SR wire, and from the connector interface to the LH front window motor on a SK wire. 
The motor is energised and drives the window mechanism towards the down position.
The front left window motor is earthed via an SU wire to connector interface C0744-6/C0463-
6, and an SB wire from the connector interface to pin C0664-4 on the BCU. The BCU 
completes the earth via pin C0664-5 on a B wire to earth header C0018 LHD/C0017 RHD. 
						

							DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.13
Front right window up
The right window switch up contact is connected to pin C0660-19 on the BCU by a BU wire. 
When the switch is set to the up position an internal supply from the BCU flows along the 
BU wire through the contacts of the switch and to earth via earth header C0552 on a B wire.
The BCU internal logic monitors the current flow from pin C0660-19 and uses this input as 
an up signal. The BCU routes power from the permanent feed from pin C0664-7 to pin 
C0664-6, from pin C0664-6 on an SK wire to connector C0326-2 on the RH front window 
motor. The motor is energised and drives the window mechanism towards the up position.
The front right window lift motor is earthed via an SK wire to connector C0664-2 on the BCU. 
The BCU completes the earth via pin C0664-5 on a B wire to earth header C0018 LHD/
C0017 RHD.
Front right window down
The right window switch down contact is connected to pin C0660-2 on the BCU by a BK wire. 
When the switch is set to the down position an internal supply from the BCU flows along the 
BK wire through the contacts of the switch and to earth via earth header C0552 on a B wire.
The BCU internal logic monitors the current flow from pin C0660-2 and uses this input as a 
down signal. The BCU routes power from the permanent feed from pin C0664-7 to pin 
C0664-2. From pin C0664-2, the power flows to the RH front window motor on an SU wire. 
The motor is energised and drives the window mechanism towards the down position.
The front right window motor is earthed via an SK wire to connector C0664-6 on the BCU. 
The BCU completes the earth via pin C0664-5 on a B wire to earth header C0018 LHD/
C0017 RHD.
Ignition key modes
Depending on the vehicle specification:
The BCU controls operation of the front windows and will allow operation for a period of 44 
seconds after the ignition switch is moved to the off position.
On some models if the time is less than 44 seconds and the drivers door (or any door on 
some models) is opened the BCU will disable the function of the windows.
On some models the BCU disables the windows as soon as the ignition is turned off.
On all models the windows will not operate while the ignition key is turned to the cranking 
position III. 
						

							DESCRIPTION AND OPERATION
4.14DISCOVERY SERIES II
WINDOWS - REAR
DESCRIPTION
Windows - Rear
The rear windows are electrically operated from two rockers switches located in the centre 
console. A rocker switch located in each rear door trim panel also operates the 
corresponding rear window.
A window lift isolation switch is located in the centre console. The isolation switch prevents 
rear window operation using the rear window switches in the rear door trims, but allows 
operation from the rear window switches in the centre console.
Power to the rear window motors is enabled by the Intelligent Driver’s Module (IDM) which 
energises the rear window lift relay located in the passenger compartment fusebox.
The rear window enable is operative when the ignition switch is in position II and for a period 
of 44 seconds after the ignition is switched off or after the drivers door is opened. The rear 
window operation is suspended when the ignition switch is in the crank position III.
The rear windows are operated by electric motors located in each rear door. The window up/
down functions are controlled by reversing the polarity to the motors.
OPERATION
Windows - Rear Supply
Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine 
compartment fusebox, where it passes through fusible links 1, 6 and 8. Fusible links 1 and 
6 are connected in series.
A feed from fusible links 1 and 6 is connected from the engine compartment fusebox, on an 
NU wire, to the passenger compartment fusebox, where it passes through fuse 13. From 
fuse 13, the feed is connected to the contacts and the coil of the rear window lift relay located 
in the passenger compartment fusebox.
A feed from fusible link 8 is connected from the engine compartment fusebox, on an NW 
wire, to the passenger compartment fusebox. From the passenger compartment fusebox the 
feed is connected to the ignition switch on an N wire. 
						

							DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.15
Ignition switch supply
With the ignition switch in position II, the feed from fusible link 8 passes through the ignition 
switch to fuse 29 in the passenger compartment fusebox on a Y wire.
When the ignition switch is in position II, the feed from fuse 29 is connected to the IDM. The 
IDM logic connects the feed from fuse 13 in the passenger compartment fusebox through 
the coil of the rear window lift relay, to earth header C0551 on a B wire. This supply 
energises the coil of the rear window lift relay.
The contacts of the rear window lift relay close when the coil is energised and allow the feed 
from fuse 13 to pass through the rear window lift relay contacts. The feed is connected from 
the passenger compartment fusebox to splice joint A183 by a WK wire. The feed is then 
connected on four WK wires to the LH and RH window console switches.
Windows - Rear Operation
LH rear window console switch - down
Operation of the LH window console switch in the down position, allows the feed from the 
rear window lift relay to pass through the up switch contacts to the LH rear window switch 
on an SW wire. The feed passes through the up switch contacts and is connected to the LH 
rear window motor on an SO wire.
When the LH window console switch is set in the down position, the contacts complete the 
earth path for the LH rear window motor. The LH rear window motor is earthed via an SR 
wire to the LH rear window switch. From the down contacts of LH rear window switch the 
earth continues on an SY wire to the closed contacts of LH window console switch. From 
the contacts of the LH rear console switch the earth continues on a B wire to earth header 
C0552.
LH rear window console switch - up
Operation of the LH window console switch in the up position, allows the feed from the rear 
window lift relay to pass through the down switch contacts to the LH rear window switch on 
an SY wire. The feed passes through the down switch contacts and is connected to the LH 
rear window motor on an SR wire.
When the LH window console switch is set in the up position, the contacts complete the 
earth path for the LH rear window motor. The earth path from the LH rear window motor is 
connected to the LH rear window switch on an SO wire. The earth continues through the up 
switch contacts and is connected to the LH window console switch on an SW wire. The earth 
passes through the down switch contacts and is connected to earth header C0552 on a B 
wire. 
						

							DESCRIPTION AND OPERATION
4.16DISCOVERY SERIES II
RH rear window console switch - down
Operation of the RH window console switch in the down position, allows the feed from the 
rear window lift relay to pass through the up switch contacts to the RH rear window switch 
on an SY wire. The feed passes through the up switch contacts and is connected to the RH 
rear window motor on an SO wire.
When the RH window console switch is set in the down position, the contacts complete the 
earth path for the RH rear window motor. The RH rear window motor is earthed via an SR 
wire to the down contacts of the RH rear window switch, then on a SW wire to connector 
interface C0650-3/C0804-3. From this interface the feed continues on a SN wire to the RH 
window console switch. From the RH window console switch the earth continues via the 
closed down contacts, via a B wire to earth header C0552.
RH rear window console switch - up
Operation of the RH window console switch in the up position, allows the feed from the rear 
window lift relay to pass through the down switch contacts on an SN wire to connector 
interface C0650-3/C0804-3. From this interface the feed continues on a SW wire to the RH 
rear window switch. The feed passes through the down switch contacts and is connected to 
the RH rear window motor on an SR wire.
When the RH window console switch is set in the up position, the contacts complete the 
earth path for the RH rear window motor. The earth path from the RH rear window motor is 
connected to the RH rear window switch on an SO wire. The earth continues on an SY wire 
to the up contacts of the RH rear window console switch. From the RH rear window console 
switch the earth continues on a B wire to earth header C0552.
LH rear window switch - down
Operation of the LH rear window switch in the down position, allows the feed from the rear 
window lift relay to pass through the up contacts of the LH window console switch on an SW 
wire. The feed passes through the up switch contacts and is connected to the LH rear 
window motor on an SO wire.
When the LH rear window switch is set in the down position, the contacts complete the earth 
path for the LH rear window motor. The earth path from the LH rear window motor is 
connected to the LH rear window switch on an SR wire. The earth continues through the 
down switch contacts and is connected via splice joint A358 to the window lift isolation switch 
on an SG wire. The earth is connected from the closed contacts of the window lift isolation 
switch on a B wire to earth header C0552. 
						

							DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.17
LH rear window switch - up
Operation of the LH rear window switch in the up position, allows the feed from the rear 
window lift relay to pass through the down contacts of the LH window console switch to the 
rear window switch on an SY wire. The feed passes through the down switch contacts to the 
LH rear window motor on an SR wire.
When the LH rear window switch is set in the up position, the contacts complete the earth 
path for the LH rear window motor. The earth path from the LH rear window motor is 
connected to the LH rear window switch on an SO wire. The earth continues through the up 
switch contacts and is connected via splice joint A358 to the window lift isolation switch on 
an SG wire. The earth is connected from the closed contacts of the window lift isolation 
switch on a B wire to earth header C0552.
RH rear window switch - down
Operation of the RH rear window switch in the down position, allows the feed from the rear 
window lift relay to pass through the up contacts of the RH window console switch on an SY 
wire to the RH rear window switch. The feed passes through the up switch contacts and is 
connected to the RH rear window motor on an SO wire.
When the RH rear window switch is set in the down position, the contacts complete the earth 
path for the LH rear window motor. The earth path from the RH rear window motor is 
connected to the RH rear window switch on an SR wire. The earth continues through the 
switch down contacts and is connected via splice joint A358 to the window lift isolation switch 
on an SG wire. The earth is connected from the closed contacts of the window lift isolation 
switch on a B wire to earth header C0552.
RH rear window switch - up
Operation of the RH rear window switch in the up position, allows the feed from the rear 
window lift relay to pass through the down contacts of the RH window console switch on an 
SN wire to connector interface C0650-3/C0804-3. From this interface the feed continues on 
an SW wire to the rear window switch. The feed passes through the down switch contacts 
to the RH rear window motor on an SR wire.
When the RH rear window switch is set in the up position, the contacts complete the earth 
path for the RH rear window motor. The earth path from the RH rear window motor is 
connected to the RH rear window switch on an SO wire. The earth continues through the up 
switch contacts and is connected via splice joint A358 to the window lift isolation switch on 
an SG wire. The earth is connected from the closed contacts of the window lift isolation 
switch on a B wire to earth header C0552. 
						

							DESCRIPTION AND OPERATION
4.18DISCOVERY SERIES II
Window lift isolation switch
If the window lift isolation switch is latched out, the earth path from the LH and RH rear 
window switches is broken, preventing operation of the LH and RH rear window switches. 
Rear window operation using the console switches is not affected by the isolation switch.
When the window lift isolation switch is latched out, the removal of the earth path also breaks 
the earth path for the LH and RH rear window switch illumination. Refer to interior 
illumination - Description and Operation in this manual for switch illumination circuit 
description. 
						

							DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.19
SUNROOF
DESCRIPTION
Sunroof Description
Electric sunroofs are fitted at the front and rear of the vehicle. Both sunroofs are electrically 
operated. Switches on the front overhead console control operation of the front and rear 
sunroofs.
The rear sunroof can be operated by a switch located in the rear overhead console. The 
switch is only operative when not disabled by the rear sunroof isolation switch located in the 
front overhead console.
OPERATION
Sunroof Supply
Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine 
compartment fusebox where it passes through fusible links 1, 6 and 8. Fusible links 1 and 6 
are connected in series.
The feed from fusible links 1 and 6 is connected on an NU wire to the passenger 
compartment fusebox where it passes through fuse 12. The feed is connected from fuse 12 
to supply a continuous battery feed on an NR wire to the sunroof ECU pin C0785-3.
The feed from fusible link 8 is connected on an NW wire to the passenger compartment 
fusebox and from the fusebox to the ignition switch on an N wire.
Ignition switch supply
With the ignition switch in position II, the feed from fusible link 8 passes through the ignition 
switch to the passenger compartment fusebox on a Y wire, where it passes through fuse 29. 
The feed is connected from fuse 29 to the Body Control Unit (BCU) pin C0660-1 on a GU 
wire.
Sunroof Operation
Front sunroof operation
When the ignition switch is in position II, an enable input is sent from the BCU pin C0661-9 
on a WG wire to pin C0785-10 on the sunroof ECU. When the enable input is present the 
power feed from pin C0785-3 is made available by the logic circuits in the sunroof ECU.
The sunroof ECU is earthed from pin C0785-2 on a B wire via splice joints A14 and A15 to 
earth header C0018.