DRIVER
AIDS
The XF’s main control module governs many key safety functions including
Emergency Brake Assist (EBA), Electronic Brakeforce Distribution (EBD),
Anti-lock Braking System (ABS), Traction Control through engine and
brake intervention, Dynamic Stability Control (DSC), Cornering Brake
Control (CBC) and Engine Drag Torque Control. And for the first time,
the XF adds Understeer Control Logic, which has been designed to mitigate
understeer by intervening through the engine management and braking
systems to decelerate the car and help restore grip to the front wheels.
A two-stage DSC system similar to that featured on the new XK is standard.
It combines the normal on-off switchable DSC function, which reacts
as soon as it detects slip, with Trac DSC, which allows more slip before
intervening – better for a more sporting driving experience. It also
allows a degree of wheel overspin on deep soft surfaces, which is essential
for running with snow chains. The system defaults to normal ‘DSC on’
with each ignition-on sequence.
In Dynamic Mode (SV8 only), pressing and holding the DSC button fully
disables the system, allowing an experienced driver to exploit fully
the capability of the chassis, where conditions allow. Mode selection
is confirmed on the instrument cluster display.
Also new on XFs fitted with Adaptive Cruise Control (ACC) is Electronic
Brake Prefill. This senses any rapid throttle lift-off and initiates
a small brake hydraulic pressure build-up in anticipation of the brakes
being applied, to give better pedal response and slightly shorter stopping
distances.
JaguarDrive Control TM offers different modes that interact with the
DSC system, engine and gearbox, to change the characteristics of engine
mapping, transmission shifts and brake interventions depending on driving
conditions and circumstances. On naturally aspirated cars JaguarDrive
Control TM has Normal and Winter modes, on the SV8 model there are Normal,
Winter and Dynamic modes - the last of these to allow a more purposeful
driving style.