1994 JAGUAR XJ6 traction control

12.1.1 0 Hydrauric Operation - ABS 1 TC CM
ABS/TC CM hydraulic modules incorporate inlet valves (items 16 and 17) and outlet valves (items 20 and 21) for each
driven wheel. This enables individual pressure modulation to the rear brakes under wheel spin conditions, i.e. traction
control.
Increased wheel spin of
a driven wheel under acceleration causes the NO isolation valve (item 14) to be closed and the
pump (item 10) to be switched on. This in response to signals from the control module.
Closing of the isolation valve blocks delivery of the pump to the secondary circuit (item
2) of the TMC. The pump now
draws fluid from the reservoir via the open hydraulically operated inlet valve (item 13). Increased pressure is now avail-
able at the inlet valves (items 16 and 17) for actuating the rear brakes, thus decreasing the tendency of wheel spin.
The hydraulic inlet valve (item
13) switches when traction control is initiated to change the suction connection
of the pump from the accumulators (item 9) to the fluid reservoir (item 6) via the TMC.
1. TMC 1 (primary circuit)
8
I 1-
I
10. Electric DumD motor 19. Inlet valve NO
170 280
2. TMC 2 (secondary circuit) 11. Two-cirh hydraulic pump 20. Outlet valve NC
3. Tandem master cylinder 12. Damping chamber 21. Outlet valve NC
4. Vacuum booster 13. Hydraulic inlet valve 22. Outlet valve NC
5. Central valve 14. Isolation valve NO 23. Outlet valve NC
6. Fluid reservoir 15. Relief valve 7. Fluid level indicator 16. Inlet valve NO 8. Motor pump unit 17. Inlet valve NO 9. Low pressure accumulator 18. Inlet valve NO
Fig.
1 24.
Rear
brake circuit (left) 25. Rear brake circuit (right) 26. Front brake circuit (left) 27. Front brake circuit (right) ~
Issue 1 August 1994 14 X300 VSM

Brakes
The pressure at the inlet valves corresponds to the opening pressure of the relief valve (item 15) incorporated in the
isolation valve. Excess brake fluid is drained to the suction side of the pump via the relief valve and returns either to
the TMC secondary circuit and on to the
fluid reservoir, or is directly drawn on by the pump.
As soon as the spinning wheel has been braked down into the normal range of wheel spin, the NO valves (items
16 or 17) close to prevent any further increase in brake pressure. Depending upon the acceleration of the wheel, the NC
valve (item
20 or 21) may open to decrease thesecondary circuit brake pressure. NCvalves (item 17 or 18) may remain
closed in orderto achieve a brake pressure holding phase. If the pressure in the secondarycircuit needs to be increased
again, the NC valve closes again (if open) and the NO valve opens, diverting the necessary volume flow. This control
action, keeps the wheel in the range of optimum slip until the spinning tendency ceases.
The NO isolation valve
(14) remains closed throughout the traction control cycle.
An actuation of the brake, sensed by the control module, causes the traction control mode to be terminated and the
isolation valve (item
14) to be opened. The TMC pressure simultaneously closes the hydraulic inlet valve (item 13) so that the pump can no longer draw fluid from it. The ABS / TC CM now operates in normal ABS mode.
m: When traction control is initiated, speed control is deactivated (if in operation) and requires re-setting after
the traction control mode has terminated. Gear shift is inhibited on automatic transmission vehicles; no down- shifts are allowed and upshifts occur at 4800 RPM.
X300 VSM 15 Issue 1 August 1994

Brakes
12.7 HYDRAULICCONTROL MODULE- RENEW
SRO 70.60.18
70.60.1
9
Refer to Section 12.4, Brake System Bleeding before carrying out this procedure. Pay particular attention to the warn- ings and cautions relating to brake fluid, cleanliness and cleaning materials.
W: The illustration shows the hydraulic control module of a 6 cyl. vehicle with traction control. Hydraulic control
modules on non-traction control vehicles have only three outlet ports. Apart from this, the removal procedure
is the same for all vehicles.
. Raise the vehicle.
Displace the bleeder screw dust cap of the front LH caliper.
The dust cap will remain captive
on the bleed screw.
. Connect a bleeder tube and bottle to the bleeder screw (1
Fig. 1) and open the bleeder screw.
. Fit a brake pedal hold-down tool (JDS-9013) between the
brake pedal and the steering wheel. Adjust the tool to op
- erate the brake pedal 60mm down. This operation is
necessary to prevent fluid loss from the reservoirthrough
. Re-tighten the front LH caliper bleeder screw. Disconnect
the bleeder tube from the bleeder screw and remove the
tube and bottle. Refit the bleeder screw dust cap.
Undo the securing bolt of the multi-plug connector (1 Fig. 2). The bolt will remain captive. Disconnect the multi-plug
connector and reposition safely.
. Place absorbent material underneath the hydraulic con-
trol module to absorb any spillages.
Undo the tandem master cylinder CTMC) brake pipe gland
nuts (2 Fig.2) and disconnect the brake pipes.
. Fit plugs immediately to the brake pipes and the hydraulic
control module to prevent fluid
loss.
. Undo the rear brake pipe gland nuts (3 Fig. 2) at the pres- sure conscious reducing valves (PCRVs) (4 Fig. 2). Remove
the rear brake pipes.
disconnected brake pipes.
Note: Take necessary steps to prevent rotation of the
PCRVs when removing the rear brake pipes.
Fit plugs immediately to the brake pipes and the PCRVs to
. Undo and remove the PCRVs. Fit plugs immediately to the
Place PCRVs aside to be fitted later to the new hydraulic
. Undo the front brake pipe gland nuts (5 Fig. 2) and remove
. Fit plugs immediately to the brake pipes and the hydraulic
. Undo and remove the three securing nuts (6 Fig. 2) and re-
0 prevent fluid loss.
PCRVs and the hydraulic control module.
control module.
the front brake pipes.
control module to prevent fluid
loss.
move the hydraulic control module. Fia.
1
3 1 J70 296
Fia. 2
Issue 1 August 1994 X300 VSM 23

Brakes
12.8
SRO 70.60.21
PRESSURE CONSCIOUS REDUCING VALVES - RENEW
Refer to Section 12.4, Brake System Bleeding before carrying out this procedure. Pay particular attention to the warn- ings and cautions relating to brake fluid, cleanliness and cleaning materials.
Note: The illustration shows the hydraulic control module of a 6 cyl. vehicle with traction control. Hydraulic control
modules on non-traction control vehicles have only three outlet ports. Apart from this, the removal procedure
is the same for all vehicles.
. Raise the vehicle.
Displace the bleeder screw dust cap of the front LH caliper.
The dust cap will remain captive on the bleed screw.
rn Connect a bleeder tube and bottle to the bleeder screw (1 Fig. 1) and open the bleeder screw.
Fit a brake pedal hold-down tool (JDS-9013) between the
brake pedal and the steering wheel. Adjust the tool to op- erate the brake pedal 60mm down. This operation is
necessary to prevent fluid
loss from the reservoir through
disconnected brake pipes.
. Re-tighten the front LH caliper bleeder screw. Disconnect
the bleeder tube from the bleeder screw and remove the
tube and bottle. Refit the bleeder screw dust cap.
rn Place absorbent material underneath the hydraulic con- trol module to absorb any spillages.
. Undo the rear brake pipe gland nuts (1 Fig. 2) at the pres- sure conscious reducing valves (PCRVs) (2 Fig. 2). Remove
the rear brake pipes.
m: Take necessary steps to prevent rotation of the
PCRVs when removing the rear brake pipes.
Fit plugs immediately to the brake pipes and the PCRVs to
Undo and remove the PCRVs. Fit plugs immediately to the
. Clean the surrounding area.
. Fit new PCRVs to the hydraulic control module, removing
plugs immediately priorto connection. Tighten the PCRVs.
. Connect the rear hydraulic brake pipes to the PCRVs, re- moving the plugs immediately prior to connection.
Tighten the gland nuts.
prevent
fluid loss.
PCRVs
and the hydraulic control module.
0
Note: Take necessary steps to prevent rotation of the
PCRVs when fitting the rear brake pipes.
. Removethe absorbent material and clean the surrounding
. Ensure that all fixings are torque tightened to specified tol-
Release the brake pedal hold-down tool and remove.
. Bleed the brake system (refer to sub-section 12.4.4).
. Examine the hydraulic control module for leaks.
area.
erances. Fia.
1
Fia. 2
X300 VSM 25 Issue 1 August 1994

31
30
29
28 27
26
4 26 24 21 23 22 7 20 19 18 18 17 8
a
10
11
12
13
14
1s
1M-137
1. Tachometer 2. Speedometer
3. Battery Condition 4. FuelGauge 5. Oil Pressure 6. Coolant Temperature 7. Odometer /Trip Computer Display 8. Primary Warning Indicators (RED) 9. Exhaust Temperature 10. Low Oil Pressure 11. Seat Belt Not Fastened 12. Boot Open 13. DoorOpen 14. Coolant Level 15. Air Bag Fault 16. Status / Warning Lamps
17. Hand Brake On (RED) 18. Brake System Fault (RED)
19. Main Beam On (BLUE) 20. Direction Indicator Right (GREEN) 21. Status / Warning Lamps 22. Direction Indicator Left (GREEN) 23. Traction Control Off (GREEN) 24. Transmission Sport Mode (GREEN) 25. Charging Fault (RED) 26. Check Engine (AMBER)
27. Low Fuel Level (AMBER) 28. Anti - Lock Fault (AMBER) 29. Traction Control Fail (AMBER) 30. Bulb Fail (AMBER) 31. Washer Fluid Level (AMBER) 32. Transmission Fault (AMBER)
Fig.
1 Instrument Panel, Front Mew
w: The 'Premium Unleaded Fuel Only' caution is added to the Federal Market vehicles, also 'PARK BRAKE and
'BRAKE' replace international symbols used in all other markets.
m: Six cylinder vehicle version shown; the tachometer red-line on 12 cylinder vehicles starts at 6000 RPM.
The front of the
PECUSprogrammable instrument panel features 6 analog gauges, 22 warning lamps /tell tales and
a Liquid Crystal Display (LCD), the rear of the panel accommodates two PCB mounted connectors, one 24-way
connector, one 48-way connector, one instrument panel identification label and 14 light bulbs arranged in groups of
seven on either side. Three power inputs and two ground inputs are provided for 'POWER UP' and 'POWER DOWN'
sequence, the three power inputs comprising battery, ignition and auxiliary. The instruments are protected by a
housing
/ lens assembly.
15.2.7 Gauges
The two major gauges are tachometer and speedometer, and the four minor gauges indicate battery condition, fuel
level, oil pressure and coolant temperature.
Each gauge is contained
in a sealed non-serviceable can and must be renewed as a complete unit in case of any
damage.
CAUTION: Extreme care should be exercised when renewing instrument pand components to avoid damago to the delicate indicator needles.
X300 VSM 9 Issue 1 August 1994

86.52.01
86.91 -83
19.75.21
86.80.24
Universal garage door opener
Security
& Locking Control Module
(SLCM)
Sunroof
Mirror memory control
Seat
/ Mirror Memory (Passenger.)
Speed control
Air conditioning
(NCCM)
Transmission control
Engine Management
BPU (Body Processor Unit)
ABS (Anti
-lock Braking System &
Traction Control (where fitted).
(ABS/TC CM)
Bulb failure
Rear
Front
I Power steering
I Column / mirror ECM
Reader exciter
Location
Roof console panel
LH side upper wheel arch, inside the
trunk below fuel filler pipe
Roof console panel.
Mounted inside driver's
& passenger's
seat.
Behind passenger knee bolster.
RH side of air conditioning unit.
Behind passenger knee bolster.
RH side footwell in front of 'A' post
behind cover.
Behind passenger knee bolster.
Engine compartment below
anti-lock
braking system modulator.
Trunk inside electrical carrier box,
Engine compartment behind each
headlamp assembly.
LH side footwell on
'A' post, behind cover.
On the side of steering column.
Around the lock barrel of steering
column.
Behind passenger knee bolster below the
airbag module.
Behind bumper, LHS of vehicle
Numb
11
13
10
9
14
2
RHD
20 LHD
1
16
RHD
(1 2&6)
7 LHD
(12&16)
6 (12&16)
19 RHD
3 LHD
18 RHD
4 RHD
12
22
& 24
17 5
8
15 RHD
23 LHD
21
X300 VSM 39 issue 1 August 1994

e LmmJ
Power assisted, ventilated discs,
sliding calipers: FN60 single piston
60mm Power assisted, ventilated discs,
FN48 single piston sliding calipers
48mm Mechanical, operating
on rear
drums within bell of the rear brake
discs.
291mm
305mm
28mm. wear limit 27mm
20mm, wear limit 18,5mm
Vacuum power, hydraulic operation
Bore diameter:
25,4mm
Jurid 518
Jurid 101
Ferodo 3612
6,51 vacuum
Electrical inductive sensors at the
wheels which detect rotational
speed.
Hydraulic: vehicles
with traction
control - contains four solenoid
valves, one for each wheel; vehicles
without traction control
- contains
three solenoid valves, one for each front wheel and one for both rear
wheels.
Solid state digital
unit (integral with hydraulic module).
Specification
Braking System
Front brakes: all vehicles.. ........ .................... ........... ...
Caliper piston diameter: ..........
Rear brakes: all vehicles ..........
...
...
....................
....................
...........
...........
Caliper piston diameter ...........
Parking brake ....................
...
...
....................
....................
...........
...........
Disc diameter:
Front
.........................
Rear .........................
Front .........................
Rear .........................
Brake operation .................
Master cylinder ..................
Main brake friction pad material:
Front
........................
Rear ........................
Parking brake friction shoe material
Brake
servo booster assembly
Boost ratio
......................
Disc thickness:
...
... ....................
....................
...........
...........
...
...
...
...
....................
....................
....................
....................
...........
...........
...........
...........
...
...
.. ....................
....................
....................
...........
...........
...........
... .................... ...........
Anti-lock braking system (ABSI
Wheel sensors ................... ... .................... ...........
ABS modulator .................. ... .................... ...........
0
0
Control module type ............. ... .................... .........
Issue 1 August 1994 X300 VSM AI-95MY 3

Description Capacity Type
Door guard lamp. 12V 5W Capless long life
Flasher side repeater 12V 5W Capless long life
Fog lamp - Front. 12v 55w Halogen H3
Fog lamp
- Rear guard 12v 21w Bayonet long life
Front turn indicator
I 12v21w I Bayonet long life
Pilot lamp
I 12V 5W I Capless long life
Headlamp
I 12v55w I Halogen HI
High mounted stop lamp (where fitted). 12v Capless long life
Roof console central courtesy lamp
12V 5W Capless long life.
Roof console reading lamp
12V 6W Capless
Luggage compartment lamp
12V 5W Capless long life
License plate lamp 12V 5W Festoon
Rear turn indicator
12v 21w Bayonet yellow long
Rear quarter courtesy lamp (lower section)
12V 5W Capless long life
Rear quarter reading lamp (upper section) 12V 6W Capless
Back
-up lamp 12v 21w Bayonet long life
Stop /Tail lamp
Sun visor vanity mirror lamp
12v 1,2w Capless 286
Tail lamp 12V 5W Bayonet long life
5X5W
12V 21V 5W Twin filament bayonet long life
Indicator bulbs
Bulb Designation Holder Colour Rating
Exhaust temperature warning indicator bulb Orange 12,5V 1,2W
Low oil pressure indicator bulb
Orange 12,5V 1,2W
Seat belt warning indicator bulb
Orange 12,5V 1,2W
Boot open warning indicator bulb
Orange 12,5V 1,2W
Door open warning indicator bulb
Orange 12,5V 1,2W
Coolant level warning indicator bulb
Orange 12,5V 1,2W
Air bag fault indicator bulb Orange 12,5V 1,2W
Parking brake 'on' indicator bulb Orange 12,5V 1,2W
Brake system warning indicator bulb Orange 12,5V 1,2W
Main beam 'on' indicator bulb
Orange 12,5V 1,2W
Right turn indicator bulb Orange 12,5V 1,2W
LCD illumination bulb (right)
Orange 12,5V 1,2W
LCD illumination bulb (left) Orange 12,5V 1,2W
Left turn indicator bulb
Orange 12,5V 1,2W
Traction control 'off indicator bulb
Orange 12,5V 1,2W
Transmission sport mode indicator bulb
Orange 12,5V 1,2W
Charging fault warning bulb
Orange 12,5V 1,2W
Check engine warning indicator bulb Orange 12,5V 1,2W
0
0
0
X300 VSM Issue 1 August 1994 AI-95MY 12