2010 JAGUAR XFR Module

Speed control module vertical alignment 90° ± 0.75°
Description Nm lb-ft lb-in Speed control module retaining nuts 5 - 44 Speed control module alignment bolt lock nut 5 - 44

1 ECM (engine control module) 2 Instrument cluster 3 Clock spring 4 Speed control switches 5 Forward alert switch 6 Adaptive speed control module 7 Brake lamp/brake test switch 8 APP (accelerator pedal position) sensor

10 Electric throttle actuator 11 ABS (anti-lock brake system) module www.JagDocs.com

Published: 11-May-2011
Speed Control - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Speed Control - Overview
Description and Operation

OVERVIEW

Speed Control

The speed control system is integrated with the engine management system and uses fueling intervention to automatically
maintain a set vehicle speed. Once engaged, the system can also be used to accelerate the vehicle without using the
accelerator pedal.
The speed control system comprises the following components:

On/Off/Suspend switch
'+' and '-' (set/accelerate and decelerate) steering wheel switches
Resume switch
Clock spring
Speed control warning indicator.
Adaptive Speed Control

The adaptive speed control system uses a forward looking radar sensor to scan the road ahead, looking for objects that are
moving at a different rate to itself. When a target is identified the adaptive speed control system will monitor the time gap
between it and the target vehicle. When that gap falls below a set driver selected level the adaptive speed control system will
intervene slowing the vehicle by backing off the throttle and/ or applying the brakes, until the correct gap is attained.
The adaptive speed control system comprises the following components:
Adaptive speed control sensor
Adaptive speed control module
Steering wheel control switches
ECM (engine control module)
Electric throttle actuator
ABS (anti-lock brake system) module and pump
Adaptive speed control warning indicator (in the instrument cluster).

Published: 29-Sep-2011
Speed Control - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Speed Control - System
Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; D = High speed CAN (controller area network) bus; O = LIN (local interconnect network) bus; U =
Private CAN bus


Item Description 1 ABS (anti-lock brake system) modul 2 Forward alert switch 3 ECM (engine control module) 4 Speed control switches 5 Audio system control switches

6 Clockspring 7 APP (accelerator pedal position) sensor 8 Electric throttle actuator 9 Brake lamp/brake test switch 10 Adaptive speed control radar sensor 11 Diagnostic socket 12 Instrument cluster 13 TCM (transmission control module) 14 Adaptive speed control module


SPEED CONTROL System Operation

The speed control system uses inputs from the brake lamp/brake test switch, the APP sensor, the ECM and the ABS module.
Speed control is operated by the driver using only the steering wheel switches. When speed control is active, the ECM regulates the PWM (pulse width modulation) signals to the fuel injectors to adjust the fuel supply as required to maintain the
set speed.

During speed control operation, the ECM controls vehicle speed by adjusting fuel injection duration and timing. When the accelerator pedal is pressed with speed control active, the ECM outputs a calculated throttle angle signal in place of the actual throttle angle signals produced by the APP sensor. The calculated throttle angle is derived from fuel demand.
The minimum set speed for speed control is 18 mph (30 (km/h). Speed control is automatically suspended if the following
conditions apply:

Vehicle speed falls below 18 mph (30 km/h)
The brake pedal is pressed
The cancel button is pressed
Neutral, park or reverse gear is selected
The difference between actual speed and the set speed is too great
If the engine speed becomes near to the red line (maximum engine speed)
If the accelerator pedal is used to accelerate beyond the set speed for too long.

ADAPTIVE SPEED CONTROL
The adaptive speed control system comprises the following components:
Adaptive speed control sensor
Adaptive speed control module
Steering wheel control switches
ECM
Electric throttle actuator
ABS module and pump Adaptive speed control warning indicator.

The adaptive speed control system uses a forward looking radar sensor to scan the road ahead, looking for objects that are
moving at a different rate to itself. When a target is identified the adaptive speed control system will monitor the time gap
between it and the target vehicle. When that gap falls below a set driver selected level the adaptive speed control system will
intervene slowing the vehicle by backing off the throttle and/ or applying the brakes, until the correct gap is attained. The
driver can chose between four gap settings, 1, 1.4, 1.8 and 2.2 seconds.
The system will detect but not react to the following:
Vehicles in the oncoming lane
Stationary vehicles
Pedestrians
Vehicles not in the same lane.

Adaptive speed control is active when the vehicle is moving. Adaptive Speed Control only functions when a set speed is
entered in normal speed control mode. The adaptive speed control system only intervenes with the set speed when it detects
a target vehicle, and then only if the minimum time gap is breached.

It is important to note that the system is intended for use in limited driving situations, does not remove control and
responsibility from the driver, and at all times can be quickly overridden. The adaptive speed control system is not a collision
warning system and will not react to stationary objects. The system does not operate below a minimum speed of
approximately 30 km/h (20 mph) since it is unsuitable for use in cities or congested traffic. The system is best suited to main
roads/ highways with gradual bends.
The ECM, throttle body and throttle control are unchanged from those used for non adaptive speed control variants.
The adaptive speed control system is based on the use of a front mounted radar sensor. The sensor transmits a 1.5° wide
beam forward of the vehicle and detects the returning signals reflected off other vehicles and objects ahead.
The 1.5° wide radar beam is mechanically scanned at a rate of 10 sweeps/second across a total arc of 15° centered on the

longitudinal axis of the vehicle. The radar operates at millimetric wavelengths (76 - 77 GHz) and transmits a frequency
modulated continuous wave signal at a relatively low power level (no high power pulses).

With the ignition ON, the adaptive speed control module is powered up but no radar transmissions are emitted until the
vehicle is in motion.

In follow mode a set speed is selected in the normal speed control manner and this speed is maintained until a slower vehicle
is encountered in the lane ahead. When the vehicle ahead comes within the effective range of the radar sensor, the system
identifies it as a target vehicle and an icon is illuminated on the instrument cluster to indicate that the system is in "follow
mode". When the distance between the two vehicles closes to a set time gap, the adaptive speed control system closes the
throttle and if necessary applies the brakes to maintain the set time gap. Follow mode is effectively a closed loop system. If
several vehicles are ahead, the closest vehicle is chosen as the target to follow. If the target vehicle moves out of radar range,
or if either vehicle changes lane or drops below the minimum operating speed, the system exits follow mode and the follow
mode icon is extinguished. The adaptive speed control system will only raise its speed to the originally set speed, it will not
accelerate past this speed to maintain a time gap.
Driver operation of the foot brake or control switches will immediately cancel adaptive speed control.

When the vehicle is in follow mode the follow mode warning indicator is illuminated in the instrument cluster and the current
gap setting will be displayed in the message center.






The radar sensor detects three primary parameters of objects within the scanned arc. These are:
Range
Relative velocity
Angle.

Range: The radar sensor detects the presence and ranges of different vehicles and objects within the scanned arc up to a
distance of approximately 130 meters. The transmitted signal frequency changes continuously in a cyclic pattern (modulation).
This means that, in the time taken for the signal wave front, to travel to and from a target vehicle (or other object), the
transmission frequency will have changed. The difference between the received signal frequency and the new transmission
frequency is proportional to the distance between the transmitting vehicle and the target vehicle.

Relative velocity: When the signal is reflected off a vehicle moving at a different speed (opening or closing gap) an effect
known as the Doppler shift causes an extra frequency modulation to be imposed on the signal. This Doppler frequency varies
with the relative speed of the vehicle being followed, enabling the system to differentiate between vehicles traveling at
different speeds and also between moving vehicles and stationary objects.

Angle: Using a narrow angle beam to scan horizontally enables the system to distinguish between vehicles in different lanes
and between vehicles and roadside objects.

System Restrictions

The adaptive speed control system is only intended to provide enhanced speed control as described above in certain restricted
conditions. The following points should be noted: Item Description 1 Forward Alert warning indicator 2 Follow mode warning indicator

1 Set speed adjustment switch 2 Time gap switch (only on vehicles with adaptive speed control fitted) 3 Cancel switch 4 Resume switch The speed control switches are located on the RH (right-hand)side of the steering wheel. The switches are connected via fly
leads to the clock spring. The speed control switches are resistive ladder type switches which vary the resistance of a 5 volt
signal sent to them. The signal is returned along a LIN bus to the instrument cluster. The instrument cluster routes the control signals to the ECM on the medium speed CAN
Speed control is engaged by rotating the speed adjustment switch to the + or - positions. Once engaged the speed can be
varied by the speed adjustment switches. Each press of the speed adjustment switch will increase or decrease the set speed
in steps of 1 mph (2 kph).

ADAPTIVE SPEED CONTROL MODULE



The adaptive speed control module, located on the drivers side at the bottom of the 'A' post. The control module is connected
to the other vehicle systems via the high speed CAN bus. Signals from the adaptive speed control forward looking radar sensor are received on a dedicated CAN bus between the two modules.
ADAPTIVE SPEED CONTROL RADAR SENSOR



The adaptive speed control radar sensor is located in the front bumper, on the RH side above the radiator grill behind the bumper cover. The sensor is connected to the adaptive speed control, module via a private CAN bus. If the unit is replaced in service the unit must be re-aligned vertically. Horizontal alignment is achieved by putting the sensor in service mode using an
approved Jaguar diagnostic system.