2010 JAGUAR XFR ignition

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.

7 RH accelerometer 8 LH accelerometer 9 RJB (rear junction box) 10 BJB (battery junction box)
System Operation
The pedestrian protection system is operational when the vehicle is traveling at speeds between approximately 20 km/h (12.4
mph) and 45 km/h (28 mph). A vehicle speed signal is received by the pedestrian protection system control module over the
high speed CAN bus.
The system is able to determine if contact is made with a pedestrian or another object, such as a traffic cone, using signals
from accelerometers mounted behind the front bumper. When the system determines contact is made with a pedestrian it fires
the actuators to lift the rear of the hood approximately 130 mm within 35 ms of the 'fire' signal.

When an impact condition is registered, the pedestrian protection system control module outputs an impact signal on the high
speed CAN bus. This signal is used by the RJB to initiate the hazard warning lamps. If this occurs, the hazard warning lamp switch is disabled for the remainder of the current ignition cycle.

If the pedestrian protection system control module detects a fault with the system, it outputs a message on the high speed
CAN bus to the instrument cluster message center. On receipt of this, the message center will display the message 'CHECK PEDESTRIAN SYSTEM'.

The pedestrian protection system control module also stores the VIN (vehicle identification number). If a new control module
is fitted to the vehicle the Jaguar approved diagnostic tool must be used to program the unit with the vehicles VIN.
When the vehicle is delivered from the factory the pedestrian protection system is in a 'safe' plant mode. Normal operating
mode should be activated using the Jaguar approved diagnostic tool during the Pre-Delivery Inspection (PDI) prior to delivery
to the customer. For additional information, refer to the PDI manual.

If any damage is caused to the front of the vehicle, be it cosmetic or structural, repairs must be carried out in line with the
processes contained in the workshop manual. Failure to carry out the correct repair process could compromise operation of the
pedestrian protection system. Refer to GTR for the latest information.

The vehicle must be left for 1 minute after disconnecting the battery before any work can be carried out on the pedestrian
protection system.

Failure Mode Detection

In service, if any fault is detected, or any part of the system is recognized as not being present, the message center displays
the warning 'Check Pedestrian System'.

The bonnet deployment actuators are non-serviceable components, and if they must be replaced due to a fault, or due to
having been deployed, or following any other accident, their barcode labels must be read and recorded in the service database
against the vehicle VIN for security purposes.

After deployment of the pedestrian protection system, the vehicle must be stopped as soon as it is safe to do so. The hazard
warning lamps will be activated and can only be switched off by pressing the engine START/STOP button to turn the engine off
and on again. A warning message 'CHECK PEDESTRIAN SYSTEM' will appear on the message center and the vehicle should be
transported to the nearest dealer/authorised repairer. The vehicle must not be driven when the bonnet has been deployed.


NOTE: If the warning message 'CHECK PEDESTRIAN SYSTEM' appears in the message center when the bonnet has not
been deployed, the vehicle should be taken to the nearest dealer/authorised repairer immediately. It can be driven.

If any significant damage occurs to the front bumper it should be inspected by a dealer/authorised repairer as soon as
possible.



CONTROL MODULE Component Description

The control module is mounted below the hood release lever behind the side trim in the left hand front footwell.

The deployment signal is received from the pedestrian protection system control module. The second-generation system
adopted for XF is all-new to Jaguar and, although similar, differs from that introduced on XK by having an accelerometer-based
sensing system rather than a contact-sensing system. The accelerometer-based system is supplied by Bosch. Mounted very
close to the skin of the bumper, it examines the characteristics of vibration waves caused by impact. Its response time is
quicker, because it does not rely on the front of the bumper being loaded. It uses the 'saved' time to make more complex
decisions, and so has fewer error states. The speed of vehicle and the length of the bonnet define the time available to get
the bonnet into its deployed and stabilized position. It is possible, therefore, to create a time-line counting back from the
predicted moment of head impact to the time when the deployment signals need to be sent. That in turn defines a time from
first contact to decision time.
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