2010 JAGUAR XFR torque

a decrease in engine torque. At the same time the ABS module will control the HCU to apply brake pressure to the relevant wheels to correct the understeer.

Electronic Brake Prefill (Vehicles With ACC Only)

Electronic brake prefill (Bosch ESP®plus8.1), senses any rapid throttle lift off, activating a small brake hydraulic pressure
build-up of approximately 3 to 5 bar (43.5 to 72.5 lbf/in²) in anticipation of the brakes being applied.

This application produces a quicker brake pedal response and consequently slightly shorter stopping distances. The system
supports vehicles with ACC (adaptive cruise control).

When the ABS module detects rapid throttle lift off (from the signals received from the ECM over the high speed CAN bus), it controls the HCU to apply a low brake pressure to assist in a quicker brake application.
Brake Vacuum Assist (3.0L Vehicles Only)

Operation of Brake Vacuum Assist generally occurs at the beginning of an ignition cycle when brake booster vacuum levels are
low; refer to Brake Booster Vacuum sensor, below.

Brake vacuum assist operation will be recognized by the driver experiencing a vibrating brake pedal and slight modulator noise.
This will be similar to that experienced when ABS system is operating.
As the engine warms up, Brake Vacuum Assist operation will become less frequent. However, it can be become more active
when vacuum levels are low due to driving at high-altitudes, or during frequent heavy-braking.

Noise levels during Brake Vacuum Assist may vary with initial system activity being the loudest observed. In some
circumstances initial activity may be interpreted as a 'thump' noise, particularly if there is no immediate and significant Brake
Vacuum Assist functionality.
In this circumstance system behavior is normal and should not be a cause for fault investigation.



Dynamic Stability Control Switch Component Description



Item Description 1 DSC switch The DSC switch is mounted in the floor console adjacent to the JaguarDrive selector.

Published: 11-May-2011
Anti-Lock Control - Stability Assist - Yaw Rate Sensor and Accelerometer
Removal and Installation

Removal


NOTE: Removal steps in this procedure may contain installation details.

1. Refer to: Battery Disconnect and Connect (414-01 Battery, Mounting and Cables, General Procedures).

2. Refer to: Parcel Shelf (501-05 Interior Trim and Ornamentation, Removal and Installation).







Installation

3. Torque: 6 Nm
















4. CAUTION: Make sure that all diagnostic trouble codes
(DTCs) have been removed after the road test.


NOTE: Make sure that this component is installed to
the noted removal position.

1. To install, reverse the removal procedure.

Steering System - General Information - Steering System
Diagnosis and Testing

Principle of Operation Published: 11-May-2011

For a detailed description of the steering system operation, refer to the relevant Description and Operation sections of the
workshop manual. REFER to:

Power Steering (211-02 Power Steering, Description and Operation), Power Steering (211-02 Power Steering, Description and Operation), Power Steering (211-02 Power Steering, Description and Operation), Steering Linkage (211-03 Steering Linkage, Description and Operation), Steering Linkage (211-03 Steering Linkage, Description and Operation), Steering Linkage (211-03 Steering Linkage, Description and Operation), Steering Column (211-04 Steering Column, Description and Operation), Steering Column (211-04 Steering Column, Description and Operation), Steering Column (211-04 Steering Column, Description and Operation), Steering Column Switches (211-05 Steering Column Switches, Description and Operation), Steering Column Switches (211-05 Steering Column Switches, Description and Operation), Steering Column Switches (211-05 Steering Column Switches, Description and Operation).
Inspection and Verification

1. Verify the customer concern.

2. Visually inspect for obvious signs of damage and system integrity.

Visual Inspection
Mechanical Electrical
Tire condition/pressure
Fluid level
Leaks
Security, condition and correct installation of suspension components
Security, condition and correct installation of steering system components
Fuses
Harnesses for damage/corrosion
Electrical connector(s)
Damaged/corroded pins
CAUTION: If a steering gear assembly is returned under warranty with leaking output shaft seals, but there is also
damage to the steering gear boot/boots the steering gear warranty will be invalid. This is due to the steering gear output
shaft seals being damaged due to foreign materials entering the steering gear boot and damaging the steering gear output
shaft seals thereafter.

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to
the next step.
4. If the concern is not visually evident, verify the symptom and refer to the symptom chart.

Symptom Charts


WARNING: It is not possible to CHECK the torque of a patchlock bolt, if the torque is suspected to be low, the bolt must
be REMOVED/DISCARDED and a new bolt MUST be INSTALLED and torque to the correct value.


NOTE: If the module or a component is suspect and the vehicle remains under manufacturer warranty, refer to the
Warranty Policy and Procedures manual (section B1.2), or determine if any prior approval programme is in operation, prior to
the installation of a new module/component.

Fluid Leakage


NOTE: Confirm the location of the fluid leak. CLEAN the area of the leak, inspect the area and confirm the exact position.
Ensure the fluid is not from another system on the vehicle.

Symptom Possible Causes Action

Power steering
fluid leakage
Overfilled system
Correct the fluid level as required
Steering gear
Check and install new steering gear as required, refer to the new
module/component installation note at the top of the Symptom
Charts

Symptom Possible Causes Action
Damaged fluid
cap/reservoir
Check and install a new fluid cap/reservoir as required

Loose or damaged
hoses and fittings
O-ring or Dowty seals
Tighten the hose connection or latch plate fixing to the
recommended torque.
REFER to: Specifications (211-00 Steering System - General Information, Specifications).
Check and install new components as required
Install new O-ring or Dowty seals as required
Fluid cooler
Check and install a new fluid cooler as required, refer to the new
module/component installation note at the top of the Symptom
Charts
Power steering pump
Check and install a new power steering pump as required, refer to
the new module/component installation note at the top of the
Symptom Charts Functional

Symptom Possible Causes Action

Steering wheel
misalignment

Steering not correctly centred
Check the steering alignment.
REFER to: Specifications (204-00 Suspension System - General
Information, Specifications).


















Excessive free play at
steering wheel (refer to
the Steering Linkage
Inspection and Backlash
(Free play) Check in this
section)

Steering wheel loose
Check and tighten the steering
wheel retaining bolt as required.
REFER to: Specifications (211-00 Steering System - General
Information, Specifications).
Excess play in the steering linkage
Check and install new
components as required



Steering gear not correctly adjusted (causing
excessive backlash)
CAUTION: DO NOT attempt to
adjust the steering gear yoke. Failure to
follow this instruction will invalidate the
steering gear warranty

Check and install a new steering
gear as required, refer to the
new module/component
installation note at the top of
the Symptom Charts

Lower steering column universal joint pinch
bolts loose
Check and tighten the lower
steering column pinch bolts as
required.
REFER to: Specifications (211-00 Steering System - General
Information, Specifications).

Excessive wear in steering column universal
joints
Check and install a new steering
column or steering column lower
shaft as required, refer to the
new module/component
installation note at the top of
the Symptom Charts

Steering gear mounting bolts loose or
damaged
Check/tighten and install new
steering gear mounting bolts as
required.
REFER to: Specifications (211-00 Steering System - General
Information, Specifications). www.JagDocs.com

Noise

Symptom Possible Causes Action











Continuous noise

Low power steering fluid level
Check for leaks and rectify as required. For further
information refer to the symptom charts for
leakage in this section. Fill power steering fluid
reservoir to correct level
NOTE: Look for small air bubbles
visible in the fluid, air may also get
trapped in the hydraulic system

Air in hydraulic system
Bleed the power steering system.
REFER to: Power Steering System Bleeding (211-00 Steering System - General Information,
General Procedures).
Power steering pipe/hose in
contact with the vehicle body
Check and reposition, or install new IF
damaged/deformed, power steering pipe/hose
Power steering pipe/hose
restricted or twisted
Check and clear restriction to pipe/hose
Reposition power steering pipe/hose. Install new
pipe/hose IF permanently damaged/deformed

Power steering pump mounting
bolts loose
Tighten the power steering pump mounting bolts
to the correct torque.
REFER to: Specifications (211-00 Steering System - General Information, Specifications).


Noise gets worse
when system is
loaded

NOTE: Refer to the power
steering pressure check in this section

Low power steering fluid level
Aerated fluid
Low power steering pump
pressure
Check and fill power steering fluid reservoir to
correct level
Bleed the power steering system.
REFER to: Power Steering System Bleeding (211-00 Steering System - General Information,
General Procedures).
Check power steering pump pressure. If the pump
pressure is low, install a new power steering
pump
Front End Accessory
Drive (FEAD) belt
squeal
FEAD belt incorrectly tensioned
or glazed
Check FEAD belt tension
Check FEAD belt condition and install a new belt
as required
Chirp noise from the
steering pump when a
load is applied
Loose or worn FEAD belt
Check FEAD belt tension
Check FEAD belt condition and install a new belt
as required
Scrape/grind noise
from behind steering
wheel while steering
Steering column shroud foul
condition or clockspring
Correctly install the steering column shroud to
eliminate the foul condition
Install a new clockspring as required
Foreign objects
Remove foreign objects from between steering
column shroud and steering wheel/steering
column rotating components
Click
Clockspring or steering column
multifunction switch LH
Correctly install and install new components as
required
Loose universal joint pinch bolt
Install a new universal joint pinch bolt and
tighten to correct specification.
REFER to: Specifications (211-00 Steering System - General Information, Specifications).
Squeak
Steering column shroud joints
Apply Krytox spray to steering column shroud
joints
Clockspring
Install new clockspring as required

Steering nibble is a rotary oscillation or vibration of the steering wheel, which can be excited at a specific vehicle speed.
Nibble is driven by wheel and tire imbalance exciting a suspension recession mode, which then translates into steering gear
travel and finally steering wheel nibble.

Shudder (Judder)

Shudder is a low frequency oscillation of the entire steering system (tire, wheels, steering gear and linkage, etc.) when the
vehicle is steered during static-park or at low speeds. Shudder is very dependent on road surface.

Torque/Velocity Variation (Phasing/Effort Cycling)

Steering wheel torque variation occurring twice in one revolution is normally as a result of problems with the lower steering
column (intermediate shaft), but foul conditions generally result in either constant stiffness or single point stiffness.
Depending upon the orientation of the joints, the steering can feel asymmetric (torque falling off in one direction and rising in
the other) or else it can simply have pronounced peaks and troughs as the steering moves from lock to lock.

Wheel Fight (Kick Back)

Wheel fight is excess feedback of sudden road forces through the steering system and back to the driver. It is evaluated at all
vehicle speeds over cobblestones, rough roads, and potholes. The tires, wheels, and suspension generate forces into the
steering systems. Steering friction, hydraulic damping, hydraulic compliance, mechanical compliance, steering ratio, and assist
gain all affect how much is transmitted to the driver.

5. CAUTIONS:


Make sure that the area around the component is
clean and free of foreign material.


The blanking plugs must not be removed until the
power steering pipes are ready to be connected.









Filling

1. CAUTIONS:


Make sure that the area around the component is
clean and free of foreign material.


The blanking plugs must not be removed until the
power steering pipes are ready to be connected.









2. CAUTIONS:


Make sure that the area around the component is
clean and free of foreign material.


Install new o-ring seals
Torque: 20 Nm









3. Lower the vehicle.

compartment, forward of the front suspension housing.

On petrol engine vehicles, a fluid cooler is located in front of the engine cooling radiator. Diesel models do not have a fluid
cooler.

Servotronic 2 adds electronic control and speed sensitive steering to the steering gear. The Servotronic 2 feature provides easy
and comfortable steering operation when parking, improved 'road feel' at increased road speeds and adds an integrated,
positive center feel feature which optimises steering wheel torque during high speed driving. The Servotronic 2 system is
controlled by software which is incorporated into the instrument cluster. The software responds to road speed signals and
controls the power assistance via a transducer valve located on the steering gear valve housing.