1998 JAGUAR X308 four wheel drive

It is a reciprocating two
-circuit pu
mp in which one brake circuit is as signed to each pump circuit.
It supplies th
e fluid pressure and vo
lume to supply the brake circuits under ABS and Traction control.
The pump is driven by an electri
c motor, with the pump
housing incorporating two lo w pressure accumulators and
damping chambers for each brake circuit.
The ac cu
mulator stores the pressure and smooths out the output pu
lses from the pump.
ABS Warning Lamp
The sys
tem will be set in a fail-safe mode if a problem is de
tected; a warning lamp on the instrument panel will notify the
driver there is a problem.
Anti-Lock Braking Sy
stem (ABS)
The AB
S components are combined with
an hydraulic booster and a tandem master cylinder to provide a two circuit braking
system. The system comprises, four wheel speed sensor s, a brake control modulator and an ABS warning lamp.
Should a wheel start to lock-up during braking a signal tr ansmitted from the wheel speed sensor to the brake control
modulator will start the hydraulic pump. The brake control modula tor will close the input valve of the line connected to the
locked-wheel to stop any increase in fluid pressure to the br ake caliper. If this fails to prevent the wheel locking, the
pressure in the caliper will be decreased by opening the return valve until th e wheel starts accelerating again. The fluid
pressure from the return va lve is directed into the low pressure accumulator, housed in the pump.
From the low pressure accumulator, fl uid is pumped through the damping cham ber to the brake master cylinder. The
pressure to the brake caliper will then be increased in small steps to maintain maximum adhesion between the tire and road
surface. This is achieved by closing the return valve, and opening the input valve and using the hydraulic pump to increase
the pressure.
Although the system senses all four wheels independently, the rear wheels are regulated as a pair. If a sensor on a rear
wheel detects a wheel decelerating rapidly, then the fluid pressure to both wheels is reduced. The fluid pressure is then
dictated by the wheel having the lowe st adhesion with the road surface.
The ABS system will be set in a fail-safe mode if a problem is detected; a warn ing lamp on the instrument panel will notify
the driver there is a problem. The brake system will still operate conventionally and with the same standard of performance
as a vehicle not equipped with ABS.
Automa tic Stability Control (ASC)

Th
e ASC utilizes the ABS sensing arrangement to provide the maximum traction force to propel the vehicle.
The ASC is switched on when the engine is started. The system can be switched off by pressing the 'ASC OFF' (the switched
is marked 'TRAC OFF' on vehicles fitted with traction control). The switch, which is situated in the center console switchpack,
lights up to warn that the system is sw itched off. An 'ASC' amber warning light flashes on the instrument panel when the
system detects a spinning wheel.
The ASC system uses engine intervention to reduce the torque delivered to the drive wheels to prevent them spinning.
Engine torque is re duced in three ways:
The
throttle is moved towards the closed position.
The ignition is retarded. F
u
el is cut-off at the cylinder injectors.
Wheel spin is detected by the wheel sp eed sensors and communicated to the AB S/TCCM. The ABS/TCCM uses information
from the controller area network (CAN) to calculate the torque that the engine should produce to stop the wheel spinning.
Torque reductions are then requested from the engine control module (ECM ) through the CAN. The throttle is then
positioned to provide the target torque, which has been calculated to prevent wheel spin. During the transient phase of
torque reduction the fuel is cut-off and th e ignition retarded Both the fuel cut-off an d ignition retard will be restored to
normal when the throttle is set to its new position.
The ASC uses a brake control modulator with six solenoid va lves: three normally open inlet valves and three normally

Input speed is monitored by the TCM with a rationality check being made against output speed. A fault will be flagged if the
indicated input speed exceeds 7400 rpm. Additionally, a failure judgement will be made if the indicated input speed is <160
rpm with engine speed >608 rpm and output speed >224 rpm
The procedure is similar for the output sp eed diagnostic. A fault (non OBDII) will be flagged if the indicated input speed
exceeds 6712 rpm. Additionally a failure judgement will be ma de if the indicated output speed is <160 rpm and the average
road wheel speed exceeds 100 rpm.
Under normal circumstance s after the output speed diagnost ic fault code has been set, the TCM uses rear wheel speed
information to compute its calculations, this has no effect on transmission operation. However, should a second fault occur,
in the ABS system, thus making rear wheel speed information unavailable, an additional fault code will be logged.
Control Systems
Introduction
Gear selection is achieved by controlling the flow of transmission fluid to internal multi-disc clutches.
The three solenoid valves direct the transmission fluid flow to the selected clutches and the pressure regulators control the
fluid pressure to each component. One pr essure regulator serves as a master pressure control for the entire system and a
second is used exclusively for torque converter clutch lock-up operation.
The TCM controls the internal components thus determining gear selection and shift pattern.
In the event of an electronic system fault the basic function s Park, Reverse Neutral and Drive Fourth are retained by the
hydraulic system.
Transmission Control Module (TCM)

The TCM is located in the same housing as th e ECM and is accessed in the same manner.
The TCM performs several 'self check' procedur es to ensure correct operation. It is possible due to the nature of these faults
that the module will fail to communicate with other nodes. However, condemnation of the TCM should not take place until
any CAN or power supply related problems have been resolved.
There are three self check procedures for the TCM. 1. 1. Check on ROM by calculatin
g a checksum and comparing this with a known stored value.

Stator, intermediate and output shafts. Three epicyclic geartrains. Six multi-disc clutch/brake packs. Two freewheels (One-way clutches). Hydraulic pump. Parking lock assembly. Electro-hydraulic control unit. Internal harness and 13 pin connector with bayonet lock.
Hydraulic pump
This engine driven pump is located at the front of the transmission casing and provides pressure for the hydraulic
functions.
Supplies fluid under pressure to the torq ue converter, geartrain, electro-hydraulic control unit and the lubrication
circuit.
Draws fluid from the fluid pa n below the transmission casing, through a filter.
Parking lock
This component prevents movement of th e vehicle by engaging a fixed pawl with the parking lock gear located on the
output shaft. The pawl is engaged by movi ng the gear selector lever to the park (P) position.
Electro-hydraulic control unit
This unit, mounted in the transmission lower case, converts signals, mechanical from the J-gate and electrical from the
TCM, into hydraulic functions.
The following components ar e assembled to the unit:
Selector valve. Shift plate. Control valve - modulating pressure. Control valve - shift pressure. Solenoid valve 1 <-> 2 and 4 <-> 5 shift. Solenoid valve 3 <-> 4 shift. Solenoid valve 2 <-> 3 shift. Solenoid valve - converter lock-up. Speed sensors (2). Temperature sensor.
Speed sensors
There are two speed sensors within the transmission assembly which provide input to the TCM. These inputs, when used in
conjunction with CAN data relative to engine speed (from ECM) and road speed (from ABS), are used to electronically
control the transmission.
Temperature sensor
The output from this sensor allows the TCM to compensate for the affect of fluid temperature on shift time and quality
Control Systems
Hydraulic Control
The selector valve is operated directly by the J-gate and directs fluid flow for P R N D.
Of the four solenoid valves, 3 control shifts and 1 controls converter lock-up. One control valve controls modulating pressure
and the other shift pressure.
Regulating valves are used to maintain/control pressure for lu brication, normal operating functions, and the supply to the
control valves and shift valves.

Automatic Transmission/Transaxle - 4.0L SC V8 - AJ26 - Extension
Housing Seal
In-vehicle Repair
Removal
Special Tool(s)

Oil seal replacer
307-378

Driveshaft wrench
205-053
1. Disconnect the battery ground lead.
2. Select N and choc the road wheels.
3. Remove the front muffler, re fer to Operation 30.10.18.

4. Remove the engine rear mounting bracket.
1. Support the transmission.
2. Remove the bolt, engine rear mounting to transmission.
3. Remove the four bolts which secure the mounting
cross member to the body.

5. Detach the driveshaft from th e transmission drive flange.
1. If the transmission is to be refitted, mark the position of the coupling relative to the drive flange.
5. CAUTION: Under no circ umstances remove the
driveshaft to flexible coupling fixings.
2. Remove the three bolts, tr ansmission drive flange to
flexible coupling.
6. Secure the driveshaft wrench 205 - 053 to the output shaft
flange.

Body closures
Each front and rear door consists of a welded, mild steel inner frame and an outer panel. The outer panel is welded to the
waist rail and cheater of the inner frame, then bonded and clinched to fo rm the door assembly. Cosmetic PVC bead is
applied to all clinch joints. Sp onge rubber seals are mounted on the doors. Inte rnal insulation is provided by a foam water
shedder attached to the door by double-sided adhesive tape.
The door aperture B/C posts are reinforced over their full height to fully satisfy all forthcoming European and Federal side
impact legislation. The hood consists of one piece inner and outer panels clinched and bonded together, with cosmetic bead
PVC sealant applied to all clinch joints. Th e hood pivots at the front on two hinges each secured by bolts to the hood front
underside and the BIW front upper crossmem ber. Two gas struts secured to the hood by pivot pins and snap-on couplings,
support the hood in the open position. A full width insulating pad is secured by screws to the underside of the hood. A
sponge rubber tubular seal is mounted tran sversely towards the front of the hood underside. The trunk lid is of similar
construction to the hood, consisting of inner and outer pa nels clinched and bonded together and PVC bead sealed.
Incorporating a removable moulded liner and two trunk illuminati on lights, the trunk lid is supported when open, by two gas
struts, each secured to the inner wheel arch and trunk hinge by snap fittin gs. For some markets, a warning triangle is
attached to a bracket on the trunk lid underside and is retained in the open position by a rubber block.
Fascia
One-piece slush-moulded fascia on inject ion moulded armature and steel cross-rail reinforcement. Fascia support brackets
set with BIW to achieve close tolerance fit of fascia to bo dy eliminate necessity for adjustment following removal and
installation..
Fuel Filler Flap
The fuel filler comprising a hinged flap attached to the body decking panel by tw o nuts, incorporates a rubber buffer, snap-
in striker, hinge spring and fuel cap stowage magnet. The rubber fuel bowl moulding is attached via a steel armature to the
body reinforcement panel by five M5 nuts and is retained at the filler neck by a clip. The mating drain tube is fitted with an
internal filter. The fuel filler flap latch mechanism attached to the fuel bowl armatu re by two M5 nuts, includes a locking pin
and actuator which are both se rviceable items. The latch actuator operates independently from the central locking system;
it is driven directly by the se curity and locking control module. Locking of the fuel filler flap is achi eved only by operation of
the key or by the remote rf transmitter.
Seating
All front seats are equipped with electric height adjustment. In addition, both seats are available with manual or power
forward and rearward adjustment, manual or power operated headrest adjustment, 12 way electric adjustment, memory
controlled 12 way seat adjustment and integral seat heating. A side air bag module is installe d in the outboard squab wing
of each front seat. Each front seat has a non-handed, one-piece frame incorporatin g cushion and squab frames, side air bag
support bracket and seat adjuster mechanis ms. Seat switchpacks are installed on the outboard side of driver and passenger
seats and control modules are installed in the base of each seat . The standard rear seat is of fixed, bench type with full
width removable cushion. For certain mark ets, two individual rear seats are available as an option on long wheelbase
models. Both type s of rear seat are available with th ermostatically controlled heating of the cushion and sq uab. Individual
rear seats are electrically adjustable fo r squab re cline (via cushion fore and af t movement), head restraint height and
lumbar support. Separate motors provide ad justment of each seat cushion and head restraint and an electrically driven air
compressor provides variation of lumbar support. Seat adjustment is controlled via switches installed on a panel in an
extension to the centre console.Both the driver and front pass enger seat are secured to the vehicle floor at four points.
Interior Trim
The one-piece door casings are trimmed in UEV to match the seating, with wood veneer at the waistline and a carpet insert
at the front lower corner. Each casing is secured to the door inner panel by fir tree fastener s along the lower section, two
armrest fixings at the centre and veneer panel dowels and fixings at the top. The armrests which are common to front and
rear doors, are trimmed in matc hing leather or UEV according to specification. Switchpacks dedicated to driver and front or
rear passenger, are incorporated in the ar mrests. A speaker is installed in the lower section of each door and a tweeter is
incorporated behind each interior door handle escutcheon. where premium ICE is fitted, the front tweeters are installed in
the upper A posts. On each side, a graine d UEV finisher trimmed to match the head lining is secured to the 'A' post and
cantrail by fir tree fasteners locating in BIW apertures. Th e upper 'D' post finisher is trimmed and secured in the same
manner. The single piece'B' post finishers, also finished in grained matching UEV, each have a front seat belt exit aperture
and are secured to the BIW by four spring clips and two fir tree fasteners. The one-piece headlining consists of a 6mm thick
polyurethane foam membrane covered with suede effect knitted polyester. The headlining is secured to the BIW roof by
body tangs, the roof console, sun visors, combined grab handles and coat hooks, th e cantrail finishers and where fitted, the

Interior Trim and Ornamentation - Interior Trim
Description and Operation
Carpets
The passenger compartment carpet is a one piece moulded constr uction with integral sound deadening material, heel mats
and driver's footrest. The carpet is attach ed to the vehicle floor by plastic clips fitted below the door treadplates. Removal of the carpet necessitates re moval of the front seats, lifting of the centre console rear extens ion and removal of the heelboard
carpet.
Fascia
The full width, slush moulded, soft feel PVC fascia is mounted on an injection moulded armature and is faced with wood
veneer. In addition to the air conditioning and central, outer and demisting vents, it accepts instrument packs dedicated to
market requirements and a centrally mounted analogue clock.
Doors
The one-piece door casings are trimmed in UEV to match the seating, with wood veneer at the waistline and a carpet insert
at the front lower corner. Each casing is secured to the door inner panel by fir tree press fast eners along the lower section,
two armrest fixings at the centre and vene er panel dowels and fixings at the top. The armrests which are common to front
and rear doors, are trimmed in matching leather or UEV according to specification. The door switchpacks, dedicated to
driver and front or rear passenger, are in corporated in the armrests. A speaker is in stalled in the lower section of each door
and a tweeter is incorporated behind each interior door handle escutcheon. Where premium ICE is fitted, the front tweeters
are installed in the upper A posts.
A, B, C and D Posts
On each side,a grained UEV finisher trimmed to match the headlining is secured to the 'A' post and cantrail by fir tree
fasteners locating in BIW apertures. The upper 'D' post finisher is trimmed and secured in the same manner. The single
piece'B/C' post finishers, also finished in grained matching UEV, each have a front se at belt exit aperture and are secured to
the BIW by four spring clips and two fir tree fasteners.
Headlining
The one-piece headlining consists of a 6mm thick polyurethane foam membrane covered with suede effect knitted polyester. The headlining is secured to the BIW roof by body tangs, the roof console, sun visors, combined grab handles and coat
hooks, the cantrail finishers and where fitt ed, the sliding roof finisher and clips.
Trunk
Carpet covered trims line the trunk and are secured by fir tr ee fasteners to the sides and front inner panel. The carpet
covered, two-section, removable trunk fl oor provides access to the spare wheel and wheel changing equipment, the battery
and electrical carrier. The floor board rests on the spare wheel, with the front and rear edges locating in blocks on the fuel
tank backboard and the rear of the body. The support blocks provide for two floor he ight settings to accommodate either a
space saver or full size spare wheel.A moulded finisher covering the rear of the trunk below the sill is secured to the rear
panel by tabs and fir tree fasteners. Finish er panels fitted to the rear lamp units provide trunk interior access to the lamps.
The trunk lid underside is fitted with a removabl e moulded liner and two trunk illumination lights.

Seating - Seats Description and Operation
Front Seats

All front seats are equipped with electric height adjustment. In addition, both front seats are available with manual or power forward
and rearward adjustment, manual or powe r operated headrest adjustment, 12 way elec tric adjustment, memory controlled 12 way
adjustment and integral seat heating. A side air bag module is installed in the outboard squab wing of each front seat. Each se at has a
non-handed, one-piece frame incorporating cushion and squab frames , side air bag suppoort bracket and seat adjuster mechanisms.
Sear switchpacks are installed on the outboa rd side of driver and passenger seats, and control modules are installed in the bas e of each
seat. Both the driver and front passenger seat ar e secured to the vehicle floor at four points.
Rear Seats

The standard rear seat is of the fixed, bench type with full wi dth removable cushion. Two individual rear seats are fitted to certain long
wheelbase models. Both types of rear seat are available with thermostatically controlled heating of the cushion and squab. Indi vidual
rear seats are electrically adjustable for squab recline (via fore and aft moveme nt), head restraint height and lumbar support. Separate
motors provide adjustment of each seat cushion and head restraint and an electrica lly-driven air compressor provides variation of
lumbar support. Seat adjustment is controll ed via switches installed on a panel in a rear extension to the centre console.

Wipers and Washers - Wipers and Washers
Description and Operation
Windshield Wiper
The single wiper system is driven via a sh ort linkage, by an electric motor installed in (external on later models) a moulded
plastic weatherproof housing o ff the plenum wet area. The motor and housing are secured to the BIW bulkhead by three
bolts at the top and three screws (two on later models) with locking clips at the bottom. The complete assembly is handed
for left or right hand drive installation.
The windshield wiper is operated via the RH control column stalk switch. Operating modes are normal, high speed, flick wipe
and six settings of intermittent operation with delays ranging from 2 to 20 seconds.
Windshield Washer

The windshield washer is of wiper arm mounted running jet configuration. The je t assembly comprises two conventional
nozzles plus four nozzles of silicone rubbe r 'duckbill' design. If the system is initially operated at low ambient temperatures ,
the 'duckbill' nozzles permit an y frozen residual washer fluid to be ejected un der pump pressure. The washer jet feed tube
supplied assembled to the wiper ar m, fits at its lower end onto a central connector on the pl enum cover. Washer fluid is
conveyed by a rubber tube, from the washer pump to the jet assembly via a manifold on the underside of the plenum cover.
The windshield washer pump is installed on the rear face of the washer fluid reservoir. The 6.3 liter washer reservoir is
installed on the RH side of th e vehicle in a cavity formed by the front bu mper, the front wheel arch liner and the brake