Jaguar XK. Service manual - part 40

163

Transmission

S - Sport: The transmission operates
automatically, but the gearshift points are
modified to maximise the vehicle
response in demanding driving
conditions. This mode is not suitable for
town or highway cruising.

The automatic modes also offer
additional features:

Kick-down: Is operated when the
accelerator pedal is fully depressed
beyond the normal operating spring
pressure to provide maximum engine
performance. Kick-down is used in
circumstances where rapid acceleration
is required, such as when overtaking.

Kick-down causes the transmission to
change down to the lowest gear possible
to achieve maximum acceleration. The
gear engaged depends on the road
speed at the time of kick-down.

Driver type recognition: The
transmission monitors driving style and in
combination with sensors in the vehicle,
varies the shift schedule, fast-off, corner
recognition and shift adapt under braking
functions proportionally with driving
style.

Note: This feature is only active in S -
Sport mode.

Fast-off: Activated when rapidly
lifting-off the accelerator pedal and takes
account of road gradient. This feature
inhibits up-shifts enhancing
performance.

Note: This feature will vary its activation,
dependant upon the driver type if S -
Sport is selected.

Shift adapt under braking: Under
braking, the transmission will vary the
down-shift point in proportion to braking
effort and road gradient. This feature is
realised in conjunction with positive
torque, resulting in a smoother
down-shift.

Note: This feature will vary its activation,
dependent upon the driver type if S -
Sport is selected.

Positive torque: Provides throttle blips
on down-shifts under braking, improving
shift feel.

Note: This feature is only active in S -
Sport mode.

Corner recognition: Inhibits up-shifts
during cornering to provide improved
vehicle balance.

Note: This feature will vary its activation,
dependent upon the driver type if S -
Sport is selected.

Road gradient adaption: When the
vehicle is being driven on roads with
uphill gradients, the transmission adapts
the shift pattern to make better use of
engine power.

When driving on roads with long downhill
gradients, the transmission may
automatically select a lower gear to
increase engine braking. Selecting S will
increase the tendency of the transmission
to select a lower gear in these conditions,
further increasing engine braking.

Note: It is also possible to manually
select a lower gear to increase engine
braking via use of the shift paddles.

Transmission

164

Cruise control: When cruise control is
active, the transmission selects a shift
pattern to suit cruise control operation.
See USING CRUISE CONTROL
(page 177).

Dynamic Stability Control (DSC): When
DSC is switched ON and the system is
activated, the transmission selects a shift
pattern to suit traction control conditions.

Manual operating modes - Jaguar
Sequential Shift

Shifts in the Jaguar Sequential Shift
manual mode are optimised to provide a
rapid response to gear shift requests.
Up-shift requests are optimised for
performance via the short shift function,
this will result in a firmer shift feel than in
automatic modes. Down-shift requests
realise a throttle blip during the shift event
resulting in improved shift feel.

The Jaguar Sequential Shift modes can
be accessed either temporarily or
permanently.

Temporary manual gear selection:
When the gear selector is in the D
position, manual mode may be directly
accessed by the single action of
operating the steering wheel mounted
shift paddles.

This convenience feature allows
immediate but temporary use of the shift
paddles whilst the gear selector is in D.

If continued use of manual mode is
required, the gear selector may be
subsequently moved to the S position to
enter permanent manual mode in the
currently selected gear.

If the gear selector remains in the D
position, temporary manual mode will be
held whilst the driver is accelerating,
decelerating, cornering or continuing to
request shifts via the paddles.

The transmission will revert to automatic
operation after a short period of driving at
steady speed; alternatively the shift-up
(+) paddle may be held for a short period
(approximately one second) to return
directly to automatic operation in D.

Permanent manual gear selection:
Select the S position, permanent manual
mode then is accessed by the operation
of the steering wheel mounted shift
paddles.

The message centre will highlight the
currently selected gear.

To exit from the Jaguar Sequential Shift
permanent manual mode, move the gear
selector to the D position. The
transmission will revert to the D
automatic shift mode.

E91471

165

Transmission

Manual operation

To shift-up, briefly pull the shift-up (+)
paddle on the right-hand side of the
steering wheel towards you.

To shift-down, briefly pull the shift-down
paddle (-) on the left-hand side of the
steering wheel towards you.

The message centre display will change
to highlight the requested gear.

Note: The transmission will inhibit
up-shifts and down-shifts if the requested
shift would result in an engine speed
outside the normal operating range of the
engine. If this occurs, the message centre
will briefly display the requested gear
selection, but will return to displaying the
current gear.

The Jaguar Sequential Shift mode also
has the following features:

Kick-down: Operation of kick-down in
Jaguar Sequential Shift mode will
override the currently selected gear. The
lowest available gear will be selected for
maximum acceleration and will be
highlighted in the message centre
display. Subsequent manual shifts may
then be selected as usual.

Positive torque: Provides throttle blips
on down-shifts, improving shift feel and
response.

Shift assist: The transmission will
automatically up-shift at the engine
speed redline in Jaguar Sequential Shift
mode as if commanded manually.

The transmission will automatically
down-shift when the engine rpm drops
too low for the currently selected gear.

When the vehicle approaches, or comes
to rest, second gear is automatically
selected.

Subsequent pullaways will occur in
second gear, unless the accelerator
pedal demand is high or a down-shift is
manually selected, in which case, first
gear will be selected.

In all cases the message centre will
display the current gear.

Note: If a down-shift is requested which
would normally result in an engine speed
outside the normal operating range
during sustained braking the
transmission will indicate and hold the
requested gear in the message centre
display. The transmissions then
commence the down-shift when the
engine speed is within the normal
operating speed.

E91472

Transmission

166

Limp-home mode

In the unlikely event of an electrical or
mechanical failure, transmission
operation will be limited. The vehicle gear
selector ranges P, R, N, D can still be
used to enable the vehicle to be driven to
a safe area.

Message centre display

The message centre may display the
following messages with associated
warning indicators:

ENGINE SYSTEMS FAULT (Red)

RESTRICTED PERFORMANCE (Red or
Amber)

GEARBOX FAULT (Amber)

If any of these messages are displayed it
is likely that loss of power or driveability
will be experienced. Seek qualified
assistance as soon as possible.

Final drive unit

WARNING

The driver should be aware that
the vehicle’s performance will be
reduced and must take this into

account when driving. Also the use of the
Jaguar Sequential Shift paddles will be
disabled. In this event seek qualified
assistance as soon as posssible.

CAUTION

Although the final drive unit is a fill
for life unit, if your vehicle is used
for a race event or test track day,

then following the event the final drive
unit lubricant should be changed. You
should contact your Jaguar Dealer.

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