Range Rover P38
75
SUPPLEMENTARY RESTRAINT SYSTEM
NEW RANGE ROVER
18
DESCRIPTION AND OPERATION
Side impacts
The driver and passenger side airbags are deployed
in the event of a side impact of sufficient severity
which exceeds the side impact trigger threshold.
When the SRS diagnostic control unit senses the
impact, the diagnostic control unit activates the seat
airbag module on the side of the vehicle suffering the
impact. A current from the DCU triggers the module to
ignite pellets of nitrocellulose which generate a large
amount of Nitrogen gas, causing airbag inflation. The
inflating airbag bursts out of the seat cover at the
outboard piping and pushes the seat occupant away
from the impact force.
When fully deployed, the side airbags offer additional
protection to the front seat occupants in the event of a
collision acting on the side of the vehicle. Either the
driver’s side airbag circuit or the passenger’s side
airbag circuit is activated depending on the side of the
vehicle suffering the impact. After the airbag has fully
inflated, the airbag progressively deflates the gas from
vent holes to reduce the risk of injuries.
WARNING: Certain SRS system
components, MUST be renewed after the
side airbags have been deployed. REFER
to SRS Component Replacement Policy in this
section of the Workshop Manual.
Front angled impacts
The deployment of airbags and pre-tensioners that
occur when a vehicle is involved in a front angled
collision is dependent on the speed and angle of the
impact. Four possible conditions could apply:
•
Impact is below the threshold value for
front and side triggers - no response, none
of the airbags or seatbelt pre-tensioners
are activated.
•
The speed of the impact is in excess of the
front impact trigger threshold - the driver’s
airbag, passenger’s airbag and seatbelt
pre-tensioners are activated.
•
The speed of the impact is in excess of the
side impact trigger threshold - the driver’s
side airbag circuit is activated in a driver’s
side impact and the passenger side airbag
circuit is activated in a passenger’s side
impact.
•
Both the front and side impact trigger
thresholds are exceeded - the driver’s front
airbag, passenger’s front airbag and
seatbelt pre-tensioners are activated, and
the side airbag circuit on the side of the
vehicle suffering the impact is activated.
Rear impact and roll over
The SRS system does not specifically detect rear
impact and roll over conditions, but if as a
consequence of the crash situation the system front or
side trigger thresholds are exceeded, the relevant
airbags and pre-tensioners are deployed.