sensor JAGUAR XFR 2010 1.G Workshop Manual

Item Description 1 Battery 2 BJB 3 RJB 4 Front passenger airbag 5 Clockspring 6 Driver's airbag 7 Front passenger seat safety belt switch 8 Driver's seat safety belt switch 9 LH curtain airbag 10 Driver's seat thorax airbag 11 Front passenger seat thorax airbag 12 RH curtain airbag 13 RCM


System Operation System Operation

In a collision, the sudden deceleration or acceleration is measured by the impact sensors and the accelerometers in the
restraints control module. The restraints control module evaluates the readings to determine the impact point on the vehicle
and whether the deceleration/acceleration readings exceed the limits for firing any of the airbags, pretensioners, and battery
disconnect unit. During a collision, the restraints control module only fires the airbags and pretensioners if the safing function
confirms that the data from the impact sensor(s) indicates an impact limit has been exceeded.
The RCM incorporates the following impact thresholds to cater for different accident scenarios: Front impact, pretensioners
Front impact, driver and passenger airbags stage 1, belt unfastened
Front impact, driver and passenger airbags stage 1, belt fastened
Front impact, driver and passenger airbags stage 2, belt unfastened
Front impact, driver and passenger airbags stage 2, belt fastened
Rear impact
Driver side impact
Passenger side impact.

The front impact thresholds increase in severity from pretensioners to driver and passenger airbag stage 2, belt fastened (refer
to list above).

Firing Strategies

The safety belt pretensioners are fired when the pretensioner impact limit is exceeded. The RCM only fires the pretensioners if the related safety belt is fastened.

The driver and passenger airbags are only fired in a frontal impact. If an impact exceeds a stage 1 limit, but is less than the
corresponding stage 2 limit, only one inflator in each airbag is fired (stage 2 is still fired for disposal after a delay of 100ms).
If an impact exceeds the stage 2 limit, the two inflators in each airbag are fired simultaneously.

The passenger airbag is disabled unless the front passenger seat is occupied by a large person (NAS only), or the passenger
airbag deactivation switch is on (all except NAS & AUS).

The stage 2 inflator of the driver airbag is disabled if the driver seat is forward of the switching point of the seat position
sensor.

If there is a fault with a safety belt buckle sensor, the RCM assumes the related safety belt is fastened for the pretensioner firing strategy and unfastened for the driver and passenger airbag firing strategies. If there is a fault with the occupant
classification sensor, the RCM disables the passenger airbag. If there is a fault with the passenger airbag deactivation switch, the RCM disables the passenger airbag.
If a side impact limit is exceeded, the RCM fires the side airbag and the side head airbag on that side of the vehicle. If the side impact limit on the front passenger side of the vehicle is exceeded, the RCM also evaluates the input from the occupant classification sensor, and fires the side airbag only if the front passenger seat is occupied by a large person (NAS only).

If multiple impacts occur during a crash event, after responding to the primary impact the RCM will output the appropriate fire signals in response to any further impacts if unfired units are available.

Front and Rear Impact Firing Strategy (All Except NAS)
Safety Belt Status Strategy Driver Passenger Applicable Pretensioner Driver airbag Passenger airbag Fastened - Fired at pretensioner threshold Fired at belt fastened threshold - Unfastened - Not fired Fired at belt unfastened threshold - - Fastened Fired at pretensioner threshold - Fired at belt fastened threshold - Unfastened Not fired - Fired at belt unfastened threshold www.JagDocs.com

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.

provides the interface connection through which the side impact sensor communicates with the RCM using serial data messages. Acceleration is evaluated by the microchip and transmitted to the restraints control module, which then makes the
decision on whether or not to activate the airbags and pretensioners.

When the ignition is switched on, the RCM supplies power to the impact sensors, which perform a self-test. After satisfactory self tests the impact sensors continually output 'digital acceleration' messages to the restraints control module. If a fault is
detected the relevant impact sensor sends a fault message, instead of the digital acceleration message, to the restraints
control module. The RCM then stores a related fault code and illuminates the airbag warning indicator. Faults can be retrieved by the Jaguar approved diagnostic system from the RCM via the high speed CAN bus connection. www.JagDocs.com

position sensor consists of a Hall effect sensor attached to the driver seat frame. While the ignition is on, the RCM supplies the sensor with power, and monitors the return current. When the seat frame moves forwards, the sensor moves over the edge
of the seat track, which changes the reluctance of the sensor. The change of current is detected by the RCM and used as a switching point. The switching point is when the center of the sensor is 3 ± 4 mm from the leading edge of the seat track.

When the driver seat is forward of the switching point, the RCM increases the time delay between firing the two stages of the inflator in the driver airbag. When the driver seat is rearward of the switching point, the RCM uses the normal time delay between firing the two stages.

Safety Belt Sensor

A safety belt switch is installed in the buckle of each front safety belt to provide the RCM with a status signal of the related safety belt(s). When the safety belt is unfastened the switch outputs a low current to the RCM. When the safety belt is fastened the switch outputs a high current to the RCM.
Pretensioners



Item Description 1 Front seat safety belt switch 2 Front seat safety belt pretensioner 3 Electrical connector The pretensioners are used to tighten the front safety belts during a collision to ensure the occupants are securely held in
their seats. A pretensioner is integrated into each front safety belt buckle and attached to a bracket on the inboard side of the
seat.

Each pretensioner has a tube containing propellant and a piston. The piston is attached to a steel cable, the opposite end of
which is attached to the safety belt buckle. A squib in the base of the tube provides an ignition source when triggered by a fire
signal from the RCM.
On receipt of a fire signal from the RCM, the squib ignites the propellant. The propellant produces nitrogen gas that rapidly expands to drive the piston along the tube, pulling the cable and drawing the buckle downwards.

Operation of the airbag warning indicator is controlled by a high speed CAN bus message from the RCM to the instrument cluster. The RCM sends the signal to illuminate the airbag warning indicator if a fault is detected, and for approximately 6 seconds during the bulb check at the beginning of each ignition cycle.

Occupant Monitoring

There are two types of occupant monitoring:

In all markets except NAS & Australia, vehicles have an occupant detection sensor
In NAS markets, vehicles have an occupant classification system

For markets which have an occupant detection sensor, this has no interface with the restraints system and only provides the
belt reminder function.

For markets that have an occupant classification system, this provides the RCM with the occupancy status of the front passenger seat. The restraints control module uses this and the seat buckle status in the evaluation of the firing strategy for
the passenger front airbag, side airbag, and pretensioner.

Safety Belt Sensors

The buckle of each front safety belt incorporates a Hall effect sensor that provides a safety belt status signal to the RCM. The RCM broadcasts the status of the two front safety belts on the high speed CAN bus for use by the instrument cluster. In the event of a front impact the RCM will deploy the pretensioners provided the safety belt buckles are fastened. The safety belt buckle pretensioners have a lower deployment threshold than that required by the airbags. Hence it is possible during a minor
collision, which exceeds the deployment threshold and will deploy only the safety belt buckle pretensioners. Airbag Warning Indicator

There is a fault with the passenger airbag firing circuit(s).
The passenger airbag is deactivated with the passenger airbag deactivation switch (where fitted).
Required by passenger seat occupant monitoring (see below).

Passenger Airbag Deactivation Switch (All Except NAS)

The passenger airbag deactivation switch provides a method of manually disabling the passenger airbag. The switch is
installed in the front passenger end of the instrument panel and operated by the ignition key.

When the passenger airbag deactivation switch is operated, it changes a ground connection between two pins in the
connectors of the RCM. When the passenger airbag deactivation switch is selected to OFF, the RCM disables the passenger airbag and, if the front passenger seat is occupied, illuminates the passenger airbag deactivation indicator.

Occupant Detection System

There are two types of occupant monitoring:

In all markets except NAS & Australia, vehicles have an occupant detection sensor
In NAS markets, vehicles have an occupant classification system

For markets which have an occupant detection sensor, this has no interface with the restraints system and only provides the
belt reminder function.

For markets that have an occupant classification system, this provides the RCM with the occupancy status of the front passenger seat. The RCM uses this and the seat buckle status in the evaluation of the firing strategy for the passenger front airbag, side airbag, and pretensioner.

The occupant classification system can determine if the front passenger seat is unoccupied, occupied by a small person, or
occupied by a large person. The occupant classification system consists of:

A pressure pad, installed under the cushion of the front passenger seat, which is connected to a pressure sensor
A safety belt tension sensor, integrated into the anchor point of the front passenger safety belt
An occupant classification module, installed under the front passenger seat.

The pressure pad is a silicone filled bladder. Any load on the pressure pad is detected by the pressure sensor.

The safety belt tension sensor is a strain gauge that measures the load applied by the safety belt anchor to the anchor bolt.
The sensor is located in the lower safety belt anchor point.

Published: 10-Jul-2014
Supplemental Restraint System - Air Bag and Safety Belt Pretensioner
Supplemental Restraint System (SRS)
Diagnosis and Testing

Principle of Operation

For a detailed description of the supplemental restraints system and operation, refer to the relevant Description and Operation
section in the workshop manual. REFER to: (501-20B Supplemental Restraint System)

Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) (Description and Operation), Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) (Description and Operation), Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) (Description and Operation).
Inspection and Verification


WARNING: TO AVOID ACCIDENTAL DEPLOYMENT AND POSSIBLE PERSONAL INJURY, THE BACKUP POWER SUPPLY MUST
BE DEPLETED BEFORE REPAIRING OR REPLACING ANY AIR BAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS) COMPONENTS. TO
DEPLETE THE BACKUP POWER SUPPLY ENERGY, DISCONNECT THE BATTERY GROUND CABLE AND WAIT ONE MINUTE. FAILURE
TO FOLLOW THIS INSTRUCTION MAY RESULT IN PERSONAL INJURY.


CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not
guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.


NOTE: Given the legal implications of a restraints system failure, harness repairs to Air Bag module circuits are not
acceptable. Where the text refers to "REPAIR the circuit", this will normally mean the replacement of a harness.
1. Verify the customer concern.

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



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 cause is not visually evident, check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.

DTC Index

For a list of Diagnostic Trouble Codes (DTCs) that could be logged on this vehicle, please refer to Section 100-00.
REFER to: Diagnostic Trouble Code (DTC) Index - DTC: Restraints Control Module (RCM) (100-00 General Information, Description and Operation). Electrical

Battery condition, state of charge
Make sure all electrical connector(s) are engaged correctly on the air bag circuits
Wiring harness
Air bag module(s)
Make sure the restraints control module (RCM) is correctly installed
Fuse(s)
Sensor(s)
Pretensioner(s)
Warning lamp bulb(s) Visual Inspection
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Supplemental Restraint System - B-Pillar Side Impact Sensor
Removal and Installation

Removal


NOTE: Removal steps in this procedure may contain installation details. Published: 11-May-2011

1. Make the air bag supplemental restraint system (SRS) safe.

Refer to: Standard Workshop Practices (100-00 General Information, Description and Operation).


2. WARNING: To avoid accidental deployment and possible personal injury,
the backup power supply must be depleted before repairing or replacing
any air bag supplementary restraints system (SRS) components. To
deplete the backup power supply energy, disconnect the battery ground
cable and wait for one minute. Failure to follow this instruction may
result in personal injury.

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

3. Refer to: B-Pillar Lower Trim Panel (501-05 Interior Trim and Ornamentation, Removal and Installation).




Installation

4. Torque: 12 Nm
1. To install, reverse the removal procedure.

2. If a new component has been installed, configure using Jaguar approved
diagnostic equipment.

Supplemental Restraint System - Clockspring
Removal and Installation Published: 11-May-2011


Removal

WARNINGS:


Always wear safety glasses when repairing an air bag supplemental restraint system (SRS) vehicle and when handling an
air bag module.


Carry a live air bag module with the air bag and trim cover pointed away from your body. This will reduce the risk of injury
in the event of an accidental deployment. Failure to follow this instruction may result in personal injury.


Do not set a live air bag module down with the trim cover face down. Failure to follow this instruction may result in
personal injury.


After deployment, the air bag surface can contain deposits of sodium hydroxide, a product of the gas generant
combustion that is irritating to the skin. Wash your hands with soap and water afterwards. Failure to follow this instruction
may result in personal injury.


Never probe the connectors on the air bag module. Doing so may result in air bag deployment, which may result in
personal injury. Failure to follow this instruction may result in personal injury.


Air bag modules with discolored or damaged trim covers must be replaced, not repainted.


Vehicle sensor orientation is critical for correct system operation. If a vehicle equipped with an air bag supplemental
restraint system (SRS) is involved in a collision, inspect the sensor mounting bracket and wiring pigtail for deformation. If
damaged, replace the sensor whether or not the air bag is deployed.


To avoid accidental deployment and possible personal injury, the backup power supply must be depleted before repairing
or replacing any air bag supplemental restraint system (SRS) components. To deplete the backup power supply energy,
disconnect the battery ground cable and wait one minute. Failure to follow this instruction may result in personal injury.


CAUTION: Make sure the wheels are in the straight-ahead position. Failure to follow this instruction may result in
damage to the component.


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

1. Make the SRS system safe.

Refer to: Standard Workshop Practices (100-00 General Information, Description and Operation).

2. CAUTIONS:


Make sure that special tool 211-326 is installed to the clockspring. 211-326
Locking Tool, Clockspring Special Tool(s)
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Supplemental Restraint System - C-Pillar Side Impact Sensor
Removal and Installation

Removal


NOTE: Removal steps in this procedure may contain installation details. Published: 11-May-2011

1. Make the air bag supplemental restraint system (SRS) safe.

Refer to: Standard Workshop Practices (100-00 General Information, Description and Operation).


2. WARNING: To avoid accidental deployment and possible personal injury,
the backup power supply must be depleted before repairing or replacing
any air bag supplementary restraints system (SRS) components. To
deplete the backup power supply energy, disconnect the battery ground
cable and wait for one minute. Failure to follow this instruction may
result in personal injury.

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

3. Refer to: Rear Seat Bolster (501-10 Seating, Removal and Installation).



Installation

4. Torque: 12 Nm
1. To install, reverse the removal procedure.

2. If a new component has been installed, configure using Jaguar approved
diagnostic equipment. www.JagDocs.com