Upper Control Arm
The forged-aluminum upper control arm is a wishbone design and connects to the vehicle body through two plain bushes, and
links to the swan neck wheel knuckle by an integral ball joint. The upper control arm is inclined to provide anti-dive
characteristics under heavy braking, while also controlling geometry for vehicle straight-line stability.
Lower Control Arm
The forged aluminum lower control arms are of the wishbone design; the arms separate to allow for optimum bush tuning:
The rear lateral control arm is fitted with a bush at its inner end which locates between brackets on the subframe. The
arm is secured with an eccentric bolt which provides the adjustment of the suspension camber geometry. The outer end
of the control arm has a tapered hole which locates on a ball joint fitted to the wheel knuckle. An integral clevis bracket
on the forward face of the lateral control arm allows for the attachment of the forward control arm. A bush is fitted
below the clevis bracket to provide for the attachment of the stabilizer bar link. A cross-axis joint is fitted to a
cross-hole in the control arm to provide the location for the clevis attachment of the spring and damper assembly.
The forward control arm is fitted with a fluid-block rubber bush at its inner end which locates between brackets on the
subframe. The arm is secured with an eccentric bolt which provides adjustment of the castor and camber geometry. The
outer end of the control arm is fitted with a cross-axis joint and locates in the integral clevis bracket on the lateral
control arm.
Wheel Knuckle
The cast aluminum wheel knuckle is a swan neck design and attaches to the upper control arm and lower lateral control arm.
The lower lateral control arm locates on a non serviceable ball-joint integral with the wheel knuckle. The lower boss on the
rear of the knuckle provides for the attachment of the steering gear tie-rod ball joint.
The wheel knuckle also provides the mounting locations for the:
wheel hub and bearing assembly
the wheel speed sensor (integral to the wheel hub and bearing assembly)
brake caliper and disc shield.
Stabilizer Bar
The stabilizer bar is attached to the front of the subframe with bushes and mounting brackets. The pressed steel mounting
brackets locate over the bushes and are attached to the cross member with bolts screwed into threaded locations in the
subframe. The stabilizer bar has crimped, 'anti-shuffle' collars pressed in position on the inside edges of the bushes. The
collars prevent sideways movement of the stabilizer bar.
The stabilizer bar is manufactured from 32mm diameter tubular steel on supercharged models and 31mm diameter tubular
steel on diesel and normally aspirated models and has been designed to provide particular characteristics in maintaining roll
rates, specifically in primary ride comfort.
Each end of the stabilizer bar curves rearwards to attach to a ball joint on a stabilizer link. Each stabilizer link is secured to a
bush in the lower lateral arm with a bolt and locknut. The links allow the stabilizer bar to move with the wheel travel providing
maximum effectiveness.
The only difference between the front stabilizer bars, in addition to the diameter, is in the shape to accommodate engine
variant:
a slightly curved bar, between bush centers, for V6 diesel (31 mm dia) and V8 gasoline supercharged (32 mm dia),
a straight bar, between bush centers, for V6 and V8 normally aspirated gasoline engines (31 mm dia).
Spring and Damper Assembly
The spring and damper assemblies are located between the lower lateral arm and the front suspension housing in the inner
wing. Dependant on vehicle model there are three types of coil spring and damper available:
a standard oil passive damper (All models except supercharged),
an adaptive damper, also known as Computer Active Technology Suspension (CATS) on 4.2L supercharged vehicles up to
2010MY, For additional information refer to Vehicle Dynamic Suspension 4.2L.
a continuously variable adaptive damper, also known as Adaptive Dynamics System on 5.0L supercharged vehicles from
2010MY. For additional information refer to Vehicle Dynamic Suspension 5.0L.
The dampers are a monotube design with a spring seat secured by a circlip onto the damper tube. The damper's lower
spherical joint is an integral part of the lateral lower control-arm, and the damper takes the form of a clevis-end, which
straddles the spherical joint.
The damper piston is connected to a damper rod which is sealed at its exit point from the damper body. The threaded outer
end of the damper rod locates through a hole in the top mount. A self locking nut secures the top mount to the damper rod.
The damper rod on the adaptive damper has an electrical connector on the outer end of the damper rod.
Supercharged 4.2L vehicles up to 2010MY: The adaptive damper functions by restricting the flow of hydraulic fluid through
internal galleries in the damper's piston. The adaptive damper has a solenoid operated valve, which when switched allows a
greater flow of hydraulic fluid through the damper's piston. This provides a softer damping characteristic from the damper. The
adaptive damper defaults to a firmer setting when not activated. The solenoid is computer controlled and can switch between
soft and hard damping settings depending on road wheel inputs and vehicle speed.
Supercharged 5.0L vehicles from 2010MY: The variable damper functions by adjustment of a solenoid operated variable orifice,
which opens up an alternative path for oil flow within the damper. When de-energized the bypass is closed and all the oil flows
5. Remove and discard the retaining straps.
6. Install the steering gear.
Tighten the bolts to 100 Nm.
7. Secure the tie rod end.
Tighten the nut to 55 Nm.
8. Install the stabilizer bar link.
For additional information, refer to: Front Stabilizer Bar Link (204-01 Front Suspension, Removal and Installation).
9. Install the wheel and tire.
For additional information, refer to: Wheel and Tire (204-04 Wheels and Tires, Removal and Installation).
10. Lower the body.
11. CAUTION: The final tightening of the upper arm must be
carried out with the vehicle on it's wheels.
Tighten to 175 Nm.
12.
Install the engine undertray.
For additional information, refer to: Air Deflector (501-02 Front End Body Panels, Removal and Installation).
13. Using only four-wheel alignment equipment approved by Jaguar, check
Front Suspension - Wheel Knuckle
Removal and Installation Published: 11-May-2011
Removal
1. WARNING: Do not work on or under a vehicle supported only by a
jack. Always support the vehicle on safety stands.
Raise and support the vehicle.
2. Remove the hub assembly.
For additional information, refer to: Front Wheel Bearing and Wheel Hub - V6 3.0L Petrol (204-01 Front Suspension, Removal and Installation).
3. NOTE: LH illustration shown, RH is similar.
Remove the brake disc shield.
Remove the 3 rivets.
4. NOTES:
LH illustration shown, RH is similar.
Use an additional wrench to prevent the ball joint
rotating.
Disconnect the steering gear tie rod end ball joint.
Remove and discard the tie rod end retaining nut. Ball joint splitter
204-327 Special Tool(s)
7 Rear accelerometer 8 Instrument cluster 9 JaguarDrive selector module 10 ABS (anti-lock brake system) module 11 TCM (transmission control module) 12 ECM (engine control module) 13 RH (right-hand) rear damper 14 RH front damper 15 LH (left-hand) front damper 16 LH rear damper 17 LH rear suspension height sensor 18 RH rear suspension height sensor 19 LH front suspension height sensor 20 RH front accelerometer 21 RH front suspension height sensor 22 Adaptive damping module 23 LH front accelerometer
PRINCIPLES OF OPERATION System Operation
The adaptive damping module uses a combination of information from other system modules and data from the accelerometers
and suspension height sensors to measure the vehicle and suspension states and driver inputs. Using this information, the
adaptive damping module applies algorithms to control the dampers for the current driving conditions.
The adaptive damping module receives signals on the high speed CAN bus from the following system components: Brake Pressure - ABS module. Brake Pressure Quality Factor - ABS module. Car Configuration Parameters - AJB. Center Differential Range Actual - ECM. Engine Speed - ECM. Engine Speed Quality Factor - ECM. Engine Torque Flywheel Actual - ECM. Engine Torque Flywheel Actual Quality Factor - ECM. Gear Position Target - TCM. Lateral Acceleration - ABS module. Power Mode (Ignition Signal) - CJB. Power Mode Quality Factor - CJB. Roll Stability Control Mode - ABS module. Steering Wheel Angle - ABS module. Steering Wheel Angle Speed - ABS module. Steering Wheel Angle Status - ABS module. Terrain Mode Requested - JaguarDrive selector.
Torque Converter Slip - TCM. Vehicle Information Parameters HS - AJB Vehicle Speed - ABS module. Vehicle Speed Quality Factor - ABS module. Front Left Wheel Speed - ABS module. Front Left Wheel Speed Quality Factor - ABS module. Front Right Wheel Speed - ABS module. Front Right Wheel Speed Quality Factor - ABS module. Rear Left Wheel Speed - ABS module. Rear Left Wheel Speed Quality Factor - ABS module. Rear Right Wheel Speed Quality Factor - ABS module. Rear Right Wheel Speed - ABS module. The adaptive damping module also outputs information on the high speed CAN bus for use by other systems as follows: Fault Message - instrument cluster.
Terrain Mode Change Status - JaguarDrive selector.
Terrain Mode - JaguarDrive selector.
The adaptive damping module monitors the input signals and operates the damper solenoids. The input signals are used in
control modes and a force required for each damper for that mode is calculated. An arbitration mode monitors the force
requirements from each mode and apportions a force to a damper. The force is converted to the appropriate current and sent to
the damper.
The control modes are as follows:
each damper to the appropriate level to maintain a flat and level body.
Roll Rate Control – Uses CAN inputs. Predicts vehicle roll rate due to driver steering inputs 100 times a second and increases damping to reduce roll rate.
Pitch Rate Control – Uses CAN inputs. Predicts vehicle pitch rate due to driver throttle and braking inputs 100 times a second and increases damping to reduce pitch rate.
Bump Rebound Control – Uses suspension height sensor and CAN inputs. Monitors the position of the wheel 500 times a second and increases the damping rate as the damper approaches the end of its travel.
Wheel Hop Control – Uses suspension height sensor and CAN inputs. Monitors the position of the wheel 500 times a second and detects when the wheel is at its natural frequency and increases the dampingto reduce vertical wheel
motion.
Under normal road conditions when the vehicle is stationary with the engine running, the dampers are set to the firm condition
to reduce power consumption.
The adaptive damping module receives its power supply via a relay and fuse in the CJB. The relay remains energized for a period of time after the ignition is off. This allows the adaptive damping module to record and store any DTC (diagnostic
trouble code) relating to adaptive dynamics system faults.
DAMPERS Component Description
Item Description A Front spring and damper assembly B Rear spring and damper assembly The 'Adaptive Dynamics' dampers are monotube, nitrogen gas and oil filled units, manufactured by Bilstein. The dampers are
continuously variable, which allows the damping force to be electrically adjusted when the vehicle is being driven. The variable
dampers provide the optimum compromise between vehicle control and ride comfort.
The dampers have an electrical connector on the end of the piston rod, in the center of the top mount (the dampers look
identical to those on the Computer Active Technology Suspension (CATS) system of 4.2L supercharged vehicles, but have a
different part number).
In each damper, the continuous damping adjustment is achieved by a solenoid operated variable orifice, which opens up an
alternative path for oil flow within the damper. When de-energized the bypass is closed and all the oil flows through the main
(firm) piston. When energized, the solenoid moves an armature and control blade, which work against a spring. The control
blade incorporates an orifice which slides inside a sintered housing to open up the bypass as required. In compression, oil
flows from the lower portion of the damper through a hollow piston rod, a separate soft (comfort) valve, the slider housing and
orifice and into the upper portion of the damper, thereby bypassing the main (firm) valve. In rebound the oil flows in the www.JagDocs.com
bus allows the DLM to communicate with other systems on the vehicle.
A certain amount of differential slip is required to allow the vehicle to turn corners and to remain stable under control of the
ABS. The ADM monitors the driver's demands through primary vehicle controls and automatically sets the slip torque in the differential. The system is completely automatic and does not require any special driver input.
The differential strategy in the ADM includes:
A pre-loading function, increasing locking torque with increased driving torque.
A slip controller to decrease locking torque for optimum comfort, e.g. parking.
The ADM memorizes the position of the motor when the ignition is switched off.
CAN bus messages used by the ADM include wheel speed, steering angle, automatic transmission speed, temperature information, car configuration, axle ratios and mode inputs.
The ADM also sends messages via the CAN bus to tell other control modules on the network the status of the electronic differential. The clutch torque and default mode status are some of the main signals sent out by the ADM.
If the DLM or ADM are replaced, a Jaguar approved diagnostic system must be connected to the vehicle and the differential
self-calibration procedure must be performed. This procedure must also be performed if the motor or electronic differential is
replaced.
If a fault occurs with the electronic differential, the ADM, the DLM, or one of the required input signals, the ADM records an
error code and displays a warning in the message center.
The following messages can be displayed:
Message Description Chime E-DIFF NOT
AVAILABLE Differential temperature has reached the overheat threshold. System deactivated until temperature
returns within limits. Single E-DIFF FAULT Fault has occurred with electronic differential. System deactivated until fault rectified. Single
Brake System - General Information - Brake System
Diagnosis and Testing
Principle of Operation Published: 11-May-2011
For a detailed description of the brake system, refer to the relevant Description and Operation sections in the workshop
manual. REFER to:
Front Disc Brake (206-03, Description and Operation),
Front Disc Brake (206-03, Description and Operation),
Front Disc Brake (206-03, Description and Operation),
Rear Disc Brake (206-04, Description and Operation),
Rear Disc Brake (206-04, Description and Operation),
Rear Disc Brake (206-04, Description and Operation),
Parking Brake (206-05 Parking Brake and Actuation, Description and Operation), Parking Brake (206-05 Parking Brake and Actuation, Description and Operation), Parking Brake (206-05 Parking Brake and Actuation, Description and Operation), Hydraulic Brake Actuation (206-06 Hydraulic Brake Actuation, Description and Operation), Hydraulic Brake Actuation (206-06 Hydraulic Brake Actuation, Description and Operation), Hydraulic Brake Actuation (206-06 Hydraulic Brake Actuation, Description and Operation), Brake Booster (206-07 Power Brake Actuation, Description and Operation), Brake Booster (206-07 Power Brake Actuation, Description and Operation), Brake Booster (206-07, Description and Operation).
Inspection and Verification
Visually examine the front and rear wheel and tire assemblies for damage such as uneven wear patterns, tread worn out or
sidewall damage. Verify the tires are the same size, type and, where possible, same manufacturer. Replace the damaged
wheel or excessively worn tire.
Wheels and tires must be cleared of any foreign matter and tire pressures adjusted to the correct specification.
If the tires exhibit uneven wear or feathering, the cause must be corrected. Check the steering and suspension components for
damage or wear and, if necessary, check and adjust front wheel alignment. REFER to: (204-00 Suspension System - General
Information)
Specifications (Specifications), Front Toe Adjustment (General Procedures).
Visual Inspection
Mechanical Electrical
Brake master cylinder
Brake caliper piston(s)
Brake discs
Wheel bearings
Brake pads
Power brake booster
Brake pedal linkage
Brake booster vacuum hose
Tires
Debris
Parking brake actuator
Parking brake module
Parking brake switch
Damaged or corroded wiring harness
Brake master cylinder fluid level switch Road Test
Carry out a road test to compare actual vehicle braking performance with the performance standards expected by the driver.
The ability of the test driver to make valid comparisons and detect performance deficiencies will depend on experience.
The driver should have a thorough knowledge of brake system operation and accepted general performance guidelines to make
good comparisons and detect performance concerns.
An experienced brake technician will always establish a route that will be used for all brake diagnosis road tests. The roads
selected will be reasonably smooth and level. Gravel or bumpy roads are not suitable because the surface does not allow the
tires to grip the road equally. Crowned roads should be avoided because of the large amount of weight shifted to the low set
of wheels on this type of road. Once the route is established and consistently used, the road surface variable can be
eliminated from the test results.
Before a road test, obtain a complete description of the customer concerns or suspected condition. From the description, the
technician's experience will allow the technician to match possible causes with symptoms. Certain components will be tagged
as possible suspects while others will be eliminated by the evidence. More importantly, the customer description can reveal
unsafe conditions which should be checked or corrected before the road test. The description will also help form the basic
approach to the road test by narrowing the concern to specific components, vehicle speed or conditions.
Begin the road test with a general brake performance check. Keeping the description of the concern in mind, test the brakes at
different vehicle speeds using both light and heavy pedal pressure. To determine if the concern is in the front or rear braking
system, use the brake pedal and then use the parking brake control. If the condition (pull, vibration, pulsation) occurs only
with the parking brake, the concern is in the rear brake system.
If the concern becomes evident during this check, verify it fits the description given before the road test. If the concern is not
evident, attempt to duplicate the condition using the information from the description.
If a concern exists, use the Symptom Chart in order to isolate it to a specific sub-system and condition description. From this
description, a list of possible sources can be used to further narrow the cause to a specific component or condition.
Symptom Chart
Symptom Possible Cause Action Brakes noisy
Brake pads
Brake discs GO to Pinpoint Test A. Vibration when brakes are
applied
Wheels/tires out of balance
Wheel hub nuts loose
Brake caliper mounting bolts loose
Brake pads
Foreign material/scratches/corrosion
on brake disc contact surfaces
Excessive brake disc thickness
variation
Excessive brake disc runout
Wheel bearing wear or failure
Suspension bushing wear or failure
Steering bushing wear or failure GO to Pinpoint Test B. The brakes pull or drift
Tire pressures/wear
Brake calipers
Brake pads
Brake discs
Wheel alignment adjustment
Wheel bearing
Suspension bushings and ball joints GO to Pinpoint Test C. The pedal feels spongy
Air in brake hydraulic system
Leak in hydraulic system
Brake booster/master cylinder
Brake pads GO to Pinpoint Test D. The pedal goes down fast
Air in brake hydraulic system
Leak in hydraulic system
Brake booster/master cylinder
Brake pads GO to Pinpoint Test E. The pedal goes down
slowly
Air in brake hydraulic system
Brake booster/master cylinder GO to Pinpoint Test F. Excessive brake pedal
effort required
Brake pads
Brake booster GO to Pinpoint Test G. Brake lockup during light
brake pedal force
Brake pads
Brake calipers GO to Pinpoint Test H. Brakes drag
Parking brake control
applied/malfunction
Seized parking brake cables
Seized brake caliper slide pins
Seized brake caliper
Brake booster
Pedal gear GO to Pinpoint Test I. Excessive/Erratic brake
pedal travel
Hydraulic system
Brake pads Brake
discs
Hub and bearing assembly GO to Pinpoint Test J. The red brake warning
indicator is always on
Fluid level
Brake master cylinder fluid level
sensor
Parking brake control Fill the system to specification. Check for leaks.
Install a new brake master cylinder fluid reservoir as
required.
REFER to: Brake Fluid Reservoir (206-06 Hydraulic Brake Actuation, Removal and Installation).