2010 JAGUAR XFR rjb

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

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 Occupied allow
Fired at pretensioner
threshold -
Fired at belt fastened
threshold - Fastened
Unoccupied inhibit/empty Fired at pretensioner
threshold - Not fired - Unfastened Occupied allow Not fired -
Fired at belt unfastened
threshold Unfastened
Unoccupied inhibit/empty Not fired - Not fired The battery disconnect unit is fired:

At driver and passenger airbag belt fastened threshold in a frontal impact
At the driver and passenger side impact threshold in a side impact
At the rear impact threshold in a rear impact.

Crash Signal

When the RCM outputs any of the fire signals it also outputs a crash signal to the RJB and the ECM (engine control module) on the high speed CAN. The crash signal is also hardwired to the ECM and the RJB. The instrument cluster picks up the crash signal from the high speed CAN and gateways it to the LCM (lighting control module). On receipt of the crash signal, the RJB goes into a crash mode and the ECM cuts the power supply to the fuel pump relay. In the crash mode, the RJB: Activates all of the unlock signals of the vehicle locking system, even if the vehicle is already unlocked.
Ignores all locking/superlocking inputs until it receives an unlock input, when it returns the locking system to normal
operation.
Activates the interior lamps. The interior lamps remain on permanently until they are manually switched off at the lamp
unit, or the RJB crash mode is switched off and they return to normal operation. Disables the rear window child lock input until the crash mode is switched off.
Sends a crash message to the LCM, to activate the hazard flashers. The hazard flashers remain on until cancelled by the hazard warning switch or the crash mode is switched off.
The RJB crash mode is switched off by a valid locking and unlocking cycle of the locking system.


Restraints Control Module Component Description



The RCM is installed on the top of the transmission tunnel, in line with the B pillars, and controls operation of the SRS (supplemental restraint system). The main functions of the RCM include:
Crash detection and recording
airbag and pre-tensioner firing
Self-test and system monitoring, with status indication via the airbag warning lamp and non-volatile storage of fault
information.
The RCM determines which elements of the SRS are to be deployed by using two internal areas:

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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