2002 LAND ROVER DISCOVERY Workshop Manual

SUNROOF
76-6-10 DESCRIPTION AND OPERATION
Rear sunroof motor and microswitch
The rear sunroof motor and microswitch are located within the rear sunroof assembly. The sunroof ECU controls the
rear sunroof motor.
The sunroof ECU determines the direction the sunroof motor runs. A battery signal to one side of the motor and an
earth to the other side of the motor causes the motor to turn in one direction, reversing the polarity through the same
pins causes the motor to turn in the opposite direction.
Operating Parameters (connector connected)
Connector/Pin
No.Condition Voltage Resistance, ohms
C0785-4 Ignition in position II, rear of rear sunroof switch pressed +voltage to C0785-
6
C0785-6 Ignition in position II, front of rear sunroof switch
pressed+voltage to C0785-
4< 0.5
C0784-2 Ignition in position II, sunroof fully closed +V Batt
C0784-2 Ignition in position II, sunroof not closed > 10,0000

SUNROOF
DESCRIPTION AND OPERATION 76-6-11
Sunroof ECU
The sunroof ECU is located behind the head lining above the rear view mirror. Most functions of the sunroof ECU are
covered under other components.
Sunroof ECU connector pin details - C0784
Sunroof ECU connector pin details - C0785
Pin No. Description Input/Output
1 Rear sunroof microswitch Input
2 Front sunroof switch - open Input
3 Not used -
4 Sunroof microswitches - common Input
5 Not used -
6 Rear sunroof, rear switch - open Input
7 Rear sunroof, front switch - open Input
8 Front sunroof microswitch Input
Pin No. Description Input/Output
1 Front sunroof motor forward Output
2 ECU earth Input
3 Battery power supply Input
4 Rear sunroof motor backwards Output
5 Front sunroof motor backwards Output
6 Rear sunroof motor forwards Output
7 Front sunroof switch - close Input
8 Rear sunroof, front switch - close Input
9 Rear sunroof, rear switch - close Input
10 Sunroof enable Input

SUNROOF
76-6-12 DESCRIPTION AND OPERATION
Operation
Ignition switched-off timeout
There are three timeout modes for operating the sunroof assemblies after the ignition is switched off. The BCU
determines the vehicle's timeout mode. The three modes are:
lWhen the ignition is switched off, no sunroof operation is permitted.
lWhen the ignition is switched off, sunroof remains functional for 45 seconds or until the driver door is opened.
lWhen the ignition is switched off, sunroof remains functional for 45 seconds or until any door is opened.
Sunroof open and close
Both sunroof assemblies operate in the same manner. The front sunroof assembly has one switch while there are
two switches to control rear sunroof assembly, a rear sunroof front switch and a rear sunroof rear switch.
The sunroof ECU monitors the position of the sunroof microswitch to determine if the sunroof is to be tilted or opened.
In order for the sunroof to operate, either of the following conditions must exist:
lIgnition switch in position II.
lIgnition switched from on to off, doors closed (this may enable the system to operate for 45 seconds after the
ignition is switched off, or until a door is opened).
When the sunroof is closed, pressing the rear of the sunroof switch causes the sunroof ECU to operate the sunroof
motor and open the sunroof. When the sunroof opens, the sunroof microswitch opens. The sunroof continues to
open until the switch is released or the sunroof reaches the fully open position.
When the sunroof is open, pressing the front of the sunroof switch causes the sunroof ECU to operate the sunroof
motor and close the sunroof. The sunroof ECU continues to operate the motor until the sunroof microswitch closes.
This indicates to the sunroof ECU that the sunroof is fully closed.
Sunroof tilt
Both sunroof assemblies operate in the same manner. The front sunroof assembly has one switch while there are
two switches to control rear sunroof assembly, a rear sunroof front switch and a rear sunroof rear switch.
The sunroof ECU monitors the position of the sunroof microswitch to determine if the sunroof is to be tilted or opened.
In order for the sunroof to operate, either of the following conditions must exist.
lIgnition in position II.
lIgnition switched from on to off, doors closed (this may enable the system to operate for 45 seconds after the
ignition is switched off, or until a door is opened).
When the sunroof is closed and the front of the sunroof switch is pressed, the sunroof ECU detects the combination
of closed microswitch and front of sunroof switch being pressed and tilts the rear of the sunroof. This causes the
microswitch to open. The sunroof continues to open until the switch is released or the sunroof reaches the fully open
position.
When the sunroof is tilted and the rear of the sunroof switch is pressed, the sunroof ECU detects the combination of
open microswitch and rear of sunroof switch and closes the sunroof until the microswitch closes. This indicates to the
sunroof ECU that the sunroof is fully closed.
Rear sunroof isolation
The rear sunroof isolation switch prevents the rear sunroof rear switch from operating the rear sunroof. This can be
used to prevent small children sitting in the rear seat from playing with the rear sunroof.
Pressing the rear sunroof isolation switch opens the circuit between the rear sunroof rear switch and the sunroof ECU.
The sunroof ECU ignores the rear sunroof switch until the rear sunroof isolation switch is pressed and the circuit
closes.

SUNROOF
REPAIRS 76-6-13
REPAIRS
Sunroof - front
$% 76.84.01
Remove
1.Remove headlining.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Headlining.
2.Remove front sunroof motor.

+ SUNROOF, REPAIRS, Motor -
sunroof.
3.Disconnect drain tubes from sunroof tray.
4.Remove 14 screws securing sunroof tray to
sunroof frame.
5.Carefully remove sunroof tray.
6.With assistance, remove sunroof frame and
glass assembly. Refit
1.With assistance, fit sunroof frame and glass
assembly.
2.Position sunroof tray to roof and locate on front
edge and on rear location pin, arrowed in
illustration.
3.Fit Torx screws securing sunroof tray to frame
and tighten to 2 Nm (1.5 lbf.ft) in the order
shown.
4.Connect drain tubes to sunroof.
5.Fit sunroof motor. Do not fit headlining at this
stage.

+ SUNROOF, REPAIRS, Motor -
sunroof.
6.Check operation of sunroof.
7.Pour water over sunroof and check for water
leaks.
8.Fit headlining.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Headlining.

SUNROOF
76-6-14 REPAIRS
Sunroof - rear
$% 76.84.02
Remove
1.Remove sunroof motor.

+ SUNROOF, REPAIRS, Motor -
sunroof.
2. Models with rear A/C:
aDrill out 4 rivets securing rear centre duct to
roof.
bRelease and remove rear centre duct.
cDrill out 2 rivets securing each upper side
duct to roof.
dRemove upper side ducts.
3.Disconnect drain tubes from sunroof tray.
4.Remove 14 screws securing sunroof tray to
sunroof frame.
5.Carefully remove sunroof tray.
6.With assistance, remove sunroof frame and
glass assembly. Refit
1.With assistance, fit sunroof frame and glass
assembly.
2.Position sunroof tray to roof and locate on front
edge and on rear location pin, arrowed in
illustration.
3.Fit Torx screws securing sunroof tray to frame
and tighten to 2 Nm (1.5 lbf.ft) in the order
shown.
4.Fit sunroof motor. Do not fit headlining at this
stage.

+ SUNROOF, REPAIRS, Motor -
sunroof.
5. Models with rear A/C:
aFit upper side ducts and secure with rivets.
bFit rear centre duct and secure with rivets.
6.Connect drain tubes to sunroof.
7.Check operation of sunroof.
8.Pour water over sunroof and check for water
leaks.
9.Fit headlining.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Headlining.

SUNROOF
REPAIRS 76-6-15
Glass panel - sunroof
$% 76.84.03
The procedure for replacing the rear sunroof glass
panel is exactly the same as for the front
Remove
1.Partially open sunroof.
2.Remove 4 Torx screws securing glass to
sunroof frame.
3.Remove sunroof glass.
Refit
1.Position glass to frame.
2.Fit Torx screws securing glass to sunroof
frame. Do not fully tighten screws at this stage.
3.Adjust position of sunroof glass in relation to
roof panel until a 6.5 mm (0.25 in) gap is
produced between the front edge of the glass
and the sunroof frame.
4.Tighten sunroof glass retaining screws to 3 Nm
(2.2 lbf.ft).
Motor - sunroof
$% 76.84.07
This procedure is applicable to the motor of both
sunroofs.
Remove
1.Gain access to the sunroof motor:
lFor front sunroof motor, remove front
stowage pocket.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Stowage pocket - front.
lFor rear sunroof motor, remove headlining.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Headlining.
CAUTION: The sunroof must be fully closed
before removing the sunroof motor.
2.Disconnect sunroof motor multiplug.
3.Remove 3 Torx screws securing motor to
sunroof tray.
4.Remove sunroof motor.

SUNROOF
76-6-16 REPAIRS
Refit
1.Check sunroof motor timing notch (A) aligns
with edge of microswitch (B). If motor is out of
alignment, rotate counting wheel (C) to correct
position using an Allen key.
2.Ensure sunroof drive cables are in fully closed
position.
3.Fit motor to sunroof frame.
4.Fit Torx screws securing motor to sunroof tray
and tighten to 2 Nm (1.5 lbf.ft).
5.Connect sunroof motor multiplug.
6.Fit interior trim:
lFor front sunroof motor, fit front stowage
pocket.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Stowage pocket - front.
lFor rear sunroof motor, fit headlining.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Headlining.
Drive cable assembly
$% 76.84.09
This procedure is applicable to the drive cable
assembly of both sunroofs.
Remove
1.Remove sunroof:
lFor front drive cable assembly:

+ SUNROOF, REPAIRS, Sunroof -
front.
lFor rear drive cable assembly:

+ SUNROOF, REPAIRS, Sunroof -
rear.
2.Position sunroof assembly on suitable work
bench.
3.Remove 4 Torx screws securing glass to
sunroof frame.
4.Remove sunroof glass.
5.Release both glass carriers from cables and
remove.

SUNROOF
REPAIRS 76-6-17
6.Remove 10 Torx screws securing frame to
drive cable assembly.
7.Remove drive cable assembly from frame.
Refit
1.Fit drive cable assembly to frame.
2.Fit Torx screws securing frame to drive cable
assembly and tighten to 2.5 Nm (1.8 lbf.ft).
3.Fit glass carriers to cables.
4.Fit glass to sunroof frame and secure with Torx
screws. Do not fully tighten screws at this
stage.
5.Fit sunroof.
lFor front drive cable assembly:

+ SUNROOF, REPAIRS, Sunroof -
front.
lFor rear drive cable assembly:

+ SUNROOF, REPAIRS, Sunroof -
rear.
6.Remove timing pegs supplied with drive cables.
7.Adjust position of sunroof glass in relation to
sunroof panel until a 6.5 mm (0.25 in) gap is
produced between the front edge of the glass
and the sunroof frame.
8.Tighten sunroof glass retaining screws to 3 Nm
(2.2 lbf.ft).
Switch pack - sunroof
$% 76.84.44
Remove
1.Release switch pack from front stowage
pocket.
2.Disconnect multiplugs from 3 sunroof
switches.
3.Remove switches from switch pack.
Refit
1.Fit switches to switch pack.
2.Connect multiplugs to switches.
3.Fit switch pack to front stowage pocket.