Pedestrian Protection System: Description and Operation: Overview

Pedestrian Protection System

COMPONENT LOCATION









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 product. For additional information, refer to Standard Workshop Practices Standard Workshop Practices
The pedestrian protection system is designed to mitigate injuries in a pedestrian collision with the vehicle. It does this by utilizing a pair of pyrotechnic actuators to lift the hood away from the engine, creating a cushioned impact between the pedestrian and the vehicle.
The pedestrian protection system also includes passive protection integrated into the bumper system and bonnet structure.

WARNING: Do not fit any non-Jaguar approved accessories to the vehicle.

NOTE:
The pedestrian protection system operates independently from the SRS (supplemental restraint system).
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 (controller area network) 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 (controller area network) bus. This signal is used by the RJB (rear junction box) to initiate the hazard warning lamps. If this occurs, the hazard warning lamp switch is disabled for the remainder of the current ignition cycle.

WARNING: 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 this product. Failure to carry out the correct repair process could compromise operation of the pedestrian protection system. Refer to GTR for the latest information.
If the pedestrian protection system control module detects a fault with the system, it outputs a message on the high speed CAN (controller area network) bus to the instrument cluster message center. On receipt of this, the message center will display the message 'CHECK PEDESTRIAN SYSTEM'.

CAUTION: The vehicle must be left for 1 minute after disconnecting the battery before any work can be carried out on the pedestrian protection 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 (vehicle identification number).
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.

Hood Hinges

NOTE:
A = Non-deployed hinge; B = Deployed hinge









The hinge system incorporates a number of leaves. This includes a leaf attached to the body, an intermediate leaf and a leaf attached to the hood. During normal operation the hinge opens and closes using the hood and intermediate leaves. These are attached together by a firing pin. When the actuators are fired the firing pins fail. This allows the hood and intermediate leaves to separate and deploy the hood upwards. When the hood deploys the hood latches act as temporary hinges.

NOTE:
The hinges deform during the deployment process and will need to be replaced.


CONTROL DIAGRAM

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