2010 JAGUAR XFR Can bus

Wipers and Washers - Wipers and Washers - Overview
Description and Operation

OVERVIEW Published: 11-May-2011

The wipers and washers comprise a windshield wiper system with a conventional wiper linkage and 2 wiper blades and a
windshield washer with jets located on the wiper arms. A headlamp powerwash is available on certain models.
The front wipers have 4 operational states:
Flick wipe
Auto
Slow wipe
Fast wipe.

Operation of the windshield wipers and washers and the headlamp powerwash is controlled by the CJB (central junction box) in
response to driver inputs and signals from the rain/light sensor. The instrument cluster monitors the condition of the
wiper/washer control switch and transmits driver requests to the CJB over the medium speed CAN (controller area network) bus.

The 'Auto' function requires an input from the rain sensor. The rain sensor is mounted on the inner surface of the windshield
and transmits an infra-red signal to determine the amount of water on the outer surface of the windshield. A value is then
transmitted to the CJB over the LIN (local interconnect network) bus.

Published: 11-May-2011
Wipers and Washers - Wipers and Washers - System Operation and
Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; N = Medium speed CAN (controller area network) bus; O = LIN (local interconnect network) bus



Item Description 1 Battery 2 EJB (engine junction box) 3 Wiper motor 4 Headlamp washer pump 5 Rain/Light sensor 6 Washer reservoir fluid level switch

7 Windshield washer pump 8 Wiper/Washer switch - RH (right-hand) steering column multifunction switch 9 Instrument cluster 10 CJB (central junction box) 11 BJB (battery junction box)


WINDSHIELD WIPERS System Operation

Operation of the wipers and washers is controlled by the CJB in response to driver inputs from the wiper control switch and signals from the rain/light sensor. The instrument cluster monitors the condition of the wiper/washer control switch and
transmits driver requests to the CJB over the medium speed CAN bus.
The wiper control switch is connected via hardwired connections to the instrument cluster. The instrument cluster outputs on 4
wires a reference voltage to the wash/wipe switch, the auto wiper switch, the wiper switch and the flick wipe switch. All the
switches are connected to the instrument cluster on a common ground. Each switch function is connected to ground via a
resistor or series of resistors and the instrument cluster monitors the ground signal and determines which function has been
selected. The instrument cluster then outputs the appropriate message on the medium speed CAN bus to the CJB which responds to the requested wiper function. The CJB then activates the appropriate function either directly or via relays in the EJB for the wipers and headlamp powerwashers. Speed Dependent Mode

When the wipers are operating, a vehicle speed signal received by the CJB on the high speed CAN bus is used to operate a speed dependent mode. If the wipers are in fast wipe and the vehicle speed decreases to below 2 km/h (1.2 mph), the wipers
will reduce to the normal wipe speed. When the vehicle speed increases to above 8 km/h (5 mph) the fast wiper speed
selection is restored. If slow speed is selected and the vehicle speed drops below 2km/h (1.2 mph), the wipers will operate in
the intermittent mode. When the vehicle speed increases to above 8 km/h (5 mph) the slow wiper speed selection is restored
– this feature is configurable by the dealer using the approved Jaguar diagnostic system.
Wiper Motor

The wiper motor is controlled by the CJB. The CJB is connected to a wiper motor normal/fast relay in the EJB on 2 wires. The CJB is also connected to a wiper run/park relay, also located in the EJB.
Driver requests are received by the CJB which energizes the wiper motor normal/fast relay in the appropriate mode (normal or fast wipe) and also energizes the run/park relay in the run mode by providing a ground for the relay coils. When wiper
operation is deselected by the driver, the CJB monitors a park switch which is integral with the wiper motor. On receipt of a signal from the park switch, the CJB de-energises the run/park relay, removing the power supply through the normal/fast relay, stopping the wipers in the park position on the windshield.

The wiper motor is a DC (direct current) motor which drives a gear wheel via a worm drive attached to the motor spindle. The
motor has 3 sets of brushes with one brush connected to ground. When the normal/fast relay is energized in the normal
position, a power feed is supplied to the brush directly opposite the ground brush and operates the motor at slow speed.
When the relay is energized in the fast position, a power feed is connected to the second motor brush, which is offset from the
ground brush and operates the motor at the fast speed. With power supplied through the offset brush, the current flows
through fewer motor coil windings. This results in a lower resistance to current flow to the ground brush and produces a higher
motor rotational speed.

WINDSHIELD WASHERS

The windshield washers are controlled by the CJB. A driver request for washer operation, via the wiper control switch, is passed to the instrument cluster on the LIN bus. The instrument cluster passes the message to the CJB on the medium speed CAN bus.

The CJB energizes the windshield washer pump during the up stroke of the first 2 wash/wipe cycles. This ensures that wiper fluid is pushed to the sides of the windshield and eliminates the trail of fluid which can occur if the fluid is pushed to the
bottom of the windshield. The wipers will continue for 3 more cycles, followed after a delay of 4 seconds, by a single dry wipe.


NOTE: The dry wipe feature is configurable using an approved Jaguar diagnostic system.

The operation of the washer pump on the wiper up stroke only is configurable using an approved Jaguar diagnostic system.

The washer button can be pressed and held and the wipers will operate continuously for up to 10 seconds. After this period
when the button is released, the wipers will continue for 3 more cycles, followed after a delay, by a single dry wipe. After this
period washing will be inhibited, the wipers will continue for 3 more cycles, followed after a delay, by a single dry wipe.
Reactivating the switch will recommence the wash/wipe cycle.

RESERVOIR LEVEL SWITCH

The level switch is connected directly to the CJB. The switch is operated by a float which closes contacts within the switch when the fluid level falls to below the switch level. When the contacts are closed a ground path is completed from the CJB through the switch. This is sensed by the CJB which issues a message to the instrument cluster which displays a low fluid level warning.

HEADLAMP POWERWASHERS

The headlamp powerwash is activated when the driver requests windshield washer operation. The CJB receives the driver request via a CAN bus message from the instrument cluster. The CJB then checks for an exterior lights active signal and that a low washer fluid level signal is not present.

The CJB outputs a control voltage to a headlamp powerwash pump relay located in the EJB. The relay is energized by the CJB for a pre-determined period to allow the headlamp telescopic washers to operate.

The CJB monitors the driver washer requests and only operates the headlamp powerwash on every fourth request for windshield washer operation, provided that 10 minutes have elapsed since the last headlamp powerwash operation. The
powerwash sequence is reset when the headlamps or the ignition is switched off.


NOTE: If a low fluid reservoir level is present the CJB prohibits headlamp powerwash.
RAIN/LIGHT SENSOR

On receiving a request for automatic windshield wiper operation, the CJB interprets LIN bus messages received from the rain sensor. The rain sensor provides LIN bus messages with values ranging from 0 to 7.
A signal value of 0 is interpreted by the CJB as the windshield is dry. A signal value from 1 to 5 is interpreted by the CJB as a small amount of water hitting the windshield. In this instance, the CJB initiates a slow wipe. A signal value of 7 is interpreted by the CJB as a large amount of water hitting the windshield. In this instance, the CJB initiates a fast wipe. NOTES:


The CJB will only change a fast wipe routine to a slow wipe routine if the rain sensor value is lower than 7.

A = Clean and dry windshield; B = Wet and dirty windshield



Item Description 1 Windshield outer surface 2 Optical element 3 Transmitter diodes (100% light transmitted) 4 Rain sensor

On vehicles with headlamp powerwash, each headlamp assembly is fitted with a headlamp powerwasher. The powerwasher is
located on the underside of the headlamp assembly. The powerwasher is located in a clip at the front of the headlamp and
secured with 2 self tapping screws to the headlamp body.

The powerwasher is a telescopic unit which extends forwards from the headlamp assembly under washer fluid pressure
supplied by the headlamp powerwash pump. When the pump pressure decreases the powerwasher is automatically retracted
back into the housing. The outer end of the powerwasher is fitted with a trim which blends the powerwasher into the headlamp
when it is not operating. The powerwasher has two washer jets which direct washer fluid under high pressure onto the
headlamp lens when the powerwasher is extended.

RAIN/LIGHT SENSOR



The rain/light sensor is located at the upper edge of the windshield, behind the interior rear view mirror. Contact between the
rain sensor and windscreen is provided via a silicon pad which is compressed during the assembly process by two locking
retaining clips either side of the sensor.
The rain/light sensor unit attaches to the windshield via two clips, which latch onto formed tags on the windshield bracket.

The sensor provides information to the CJB for the optimum wiper operation for the prevailing conditions to maintain the shield in a clear condition at all times. The rain/light sensor is an optical unit, which operates on an infrared waveband. The sensor
uses the principle of the laws of reflection on interfacing surfaces between materials with differing refraction properties.

The rain/light sensor is connected to the CJB via a LIN bus. The sensor also receives a hardwired power and ground from the CJB. The 'auto' wipers are activated when the column stalk is moved to position 1 (first position from off in the upward direction). The sensitivity of the sensor can be adjusted by rotating the sensitivity collar on the wiper column stalk in the
clockwise or counterclockwise direction. Clockwise rotation will decrease sensitivity, while counterclockwise adjustment will
increase sensitivity. An increase in sensitivity adjustment results in a single wipe of the front wiper motor.


NOTE: The rain sensor also contains a light sensor. The light sensor is used to control operation of the automatic
headlamps function.
Refer to: Exterior Lighting (417-01 Exterior Lighting, Description and Operation).
WIPER CONTROL SWITCH

The wiper control switch is located on the RH steering column multifunction switch. The switch allows selection of the following functions:

Slow wipe
Fast wipe
Auto
Flick wipe
Windshield wash and headlamp powerwash (if fitted).

All wiper functions are connected to the instrument cluster by a resistor or series of resistors within the switch. The instrument
cluster uses the returned current to determine the selected function.

WIPER SERVICE POSITION

The wiper service position allows the wipers to be parked in a position to allow easy access to the wiper blades for
replacement. The service position is initiated by pulling the RH steering column multifunction switch towards the steering wheel and pressing the start/stop button to switch on the ignition. The wipers will move and stop in a vertical position on the
windshield. The RH steering column multifunction switch can be released and the ignition switched off. The service position is terminated at the next ignition on cycle and the wipers return to their normal park position.

Published: 30-May-2012
Supplemental Restraint System - Air Bag and Safety Belt Pretensioner
Supplemental Restraint System (SRS) - Overview
Description and Operation

OVERVIEW


WARNING: All pyrotechnic devices are dangerous. Before performing any procedures on any pyrotechnic device, read all
information contained within the Standard Workshop Practices section of this manual.
Refer to: Standard Workshop Practices (100-00 General Information, Description and Operation).
The SRS (supplemental restraint system) provides additional protection for the vehicle occupants in certain impact conditions.
The system is controlled by the RCM (restraints control module), which is mounted beneath the floor console. The system
includes twin stage drivers and front passenger airbags.
The RCM receives inputs from various sensors around the vehicle and determines which, if any, airbags should be deployed.
The SRS features an occupant detection system. The occupant detection system comprises a mat fitted inside the front passenger seat. By monitoring the condition of the mat, the RCM can determine if the front passenger seat is occupied. It uses this information to determine which airbags to deploy in the event of an impact. This information is also used to illuminate the
safety belt instrument cluster warning lamp if the front passenger seat is occupied and the safety belt is not engaged.

North American Specification (NAS) vehicles also feature an occupant classification system. The occupant classification system
comprises a control module, pressure pad and safety belt tension sensor. The system can determine the size and weight of the
front seat passenger. This information is transmitted to the RCM over the high speed CAN (controller area network) bus. The RCM uses this information to help determine which airbags to deploy in the event of an impact.

Published: 26-Jun-2012
Supplemental Restraint System - Air Bag and Safety Belt Pretensioner
Supplemental Restraint System (SRS) - System Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; D = High speed CAN (controller area network) bus



Item Description 1 Battery 2 BJB (battery junction box) 3 RJB (rear junction box) 4 Occupant classification system control module (NAS only) 5 Safety belt tension sensor (NAS only)

and the safety belt buckle sensor. Based on this data, the RCM decides which level of airbag module deployment is required and forwards the information to the second area, the deployment handler.

The deployment handler evaluates the status of the seat track position sensor and safety belt buckle sensors before a decision
is made about which restraints should finally be deployed.

Data from the side crash sensors is used by the RCM in conjunction with acceleration data from the RCM internal accelerometer to make a deployment decision. The RCM processes the acceleration data and subject to an impact being of high enough severity, decides whether the side airbag module should be deployed.

On board testing of the airbag modules, front safety belt pretensioner firing circuits, warning indicator circuits and module
status (the crash and side impact sensors perform basic self-tests) is performed by the RCM together with the storing of fault codes.

The RCM drives the SRS indicator on the instrument pack via a CAN signal. If the warning lamp fails, a fault code is recorded and a warning tone is sounded in place of the lamp if a further fault occurs. It also provides a temporary back-up power supply
to operate the airbag modules in the event that in crash conditions, the battery supply is lost. In the event of a crash, it
records certain data which can be accessed via the diagnostic connector.

A safing sensor in the RCM provides confirmation of an impact to verify if airbag and pretensioner activation is necessary. A roll-over sensor monitors the lateral attitude of the vehicle. Various firing strategies are employed by the RCM to ensure that during an accident only the appropriate airbags and pretensioners are fired. The firing strategy used also depends on the
inputs from the safety belt switches and the occupant monitoring system.

An energy reserve in the RCM ensures there is always a minimum of 150 milliseconds of stored energy available if the power supply from the ignition switch is disrupted during a crash. The stored energy is sufficient to produce firing signals for the
driver airbag, the passenger airbag and the safety belt pretensioners.

When the ignition is switched on, the RCM performs a self-test and then performs cyclical monitoring of the system. If a fault is detected the RCM stores a related fault code and illuminates the airbag warning indicator. The faults can be retrieved by the recommended Jaguar diagnostic tool over the CAN bus. If a fault that could cause a false fire signal is detected, the RCM disables the respective firing circuit, and keeps it disabled during a crash event.

Clock Spring



The clockspring is installed on the steering column to provide the electrical interface between the fixed wiring harness of the
steering column and the components that rotate with the steering wheel, i.e. the driver airbag, the horn and the steering
wheel switch packs.

The clockspring consists of a plastic cassette which incorporates an outer cover fixed to the steering column and an inner rotor
which turns with the steering wheel. Four securing lugs attach the cover to the multifunction switch on the steering column.
The rotor is keyed to the steering wheel by a drive peg. A lug on the underside of the rotor operates the self-cancelling feature
of the turn signal indicator switch. A ribbon lead, threaded on rollers in the rotor, links two connectors on the cover to two
connectors on the rotor. Link leads for the driver airbag are installed in one of the connectors on the rotor.

To prevent damage to the ribbon lead, both the steering and the clockspring must be centralized when removing and installing
the clockspring or the steering wheel. The clockspring is centralized when the drive peg is at six o'clock and 50 - 100% of a
yellow wheel is visible in the viewing window.

Replacement clocksprings are fitted with a stopper, which locks the cover to the rotor, in the central position. The stopper must
be broken off when the replacement clockspring is installed.