Restraints and Safety Systems: Description and Operation

Supplemental Restraint System

DESCRIPTION

Introduction
The Supplemental Restraint System (SRS) provides additional protection for occupants in certain vehicle conditions. Components within the SRS include:
^ Driver air bag.
^ Passenger air bag.
^ Side air bag on each front seat.
^ Side air curtains for front and second row seats.
^ Side air curtains for third row seats (where fitted).
^ Pre-tensioner for each front safety belt.
^ Front and side impact sensors.
^ Restraints control module.

The SRS features selective activation of the air bags and pre-tensioners. The restraints control module monitors internal and external sensors and activates the required safety belt pre-tensioners and air bags if the sensors detect an impact or roll-over above preset limits.

OPERATION

Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 11E of the Battery Junction Box (BJB) (C0632) on an R wire. Fusible link 11E (C0570) provides a feed to the ignition switch (C0028) on an N wire.

When the ignition switch is in the 'ignition' position, current flows across the switch (C0028) to fuse 9P and fuse 68P Central Junction Box (CJB) (C0582) on a Y wire. Fuse 9P (C0585) provides an ignition feed to the restraints control module (C1649) on an RW wire. Fuse 68P (C0582) provides ignition feeds to the 'Passenger Air Bag Disabled' warning lamp (C2387) on a G wire.

Impact Sensors
In addition to an internal roll over sensor, the restraints control module utilises the following impact sensors:
^ Two front impact sensors.
^ Four side impact sensors (5 seater vehicles only).
^ Six side impact sensors (7 seater vehicles only).

Front Impact Sensors
The front impact sensors are located on either end of the front cross member. The restraints control module (C1649) provides a feed to the LH sensor (C1652) on a KO wire. The sensor returns signals to the control module on a PLG wire. The restraints control module (C0256) provides a feed to the RH sensor (C1653) on a W wire. The sensor returns signals to the control module on an N wire.

Side Impact Sensors
The side impact sensors are located in the B and C pillars. Seven seater vehicles also have side impact sensors located in both front doors. The restraints control module (C0256) is connected to the sensors as follows:
^ The restraints control module provides a feed to the LH B pillar mounted sensor (C2126) on a WR wire. The sensor returns signals to the control module on a WLG wire.
^ The restraints control module provides a feed to the RH B pillar mounted sensor (C2127) on a RW wire. The sensor returns signals to the control module on a RLG wire.
^ The restraints control module provides a feed to the LH C pillar mounted sensor (C1654) on a P wire. The sensor returns signals to the control module on a GW wire.
^ The restraints control module provides a feed to the RH C pillar mounted sensor (C1655) on a WR wire. The sensor returns signals to the control module on a UW wire.
^ The restraints control module provides a feed to the LH door mounted sensor (C0950) on a WLG wire. The sensor returns signals to the control module on an NLG wire.
^ The restraints control module provides a feed to the RH door mounted sensor (C0951) on a W wire. The sensor returns signals to the control module on an N wire.

Driver Air Bag
The driver air bag is a two stage air bag, containing a pair of inflators installed side by side. The restraints control module (C1649) provides a feed to the stage 1 inflator (C0257) via the clock spring (C2641) on an RY wire. A ground path for the stage 1 inflator is provided via the clock spring (C2641) on an R wire.

The stage 2 inflator (C0406) is provided a feed by the restraints control module (C1649) via the clock spring (C2641) on an RG wire. A ground path for the stage 2 inflator is provided via the clock spring (C2641) on an RB wire.

The driver air bag is also provided a ground (C2636) via the clock spring (C0082) on a B wire.

Seat Position
The restraints control module monitors the horizontal position of the seat via a Hall effect sensor mounted on the seat frame and a target plate mounted on the seat base. If the seat is moved forward and the Hall effect sensor passes the target plate, the restraints control module deactivates the stage 2 inflator within the driver air bag. The sensor (C2363) is provided a feed by the control module (C0256) on an LG wire, and is provided a ground via an NB then B wire.

Passenger Air Bag
The passenger air bag is a two stage air bag, containing a pair of inflators installed side by side. The restraints control module (C1649) provides a feed to the stage 1 inflator (C0251) on a UO then BU wire. A ground path for the stage 1 inflator is provided by the control module on a GU then KB wire.

The stage 2 inflator (C0261) is provided a feed by the restraints control module (C1649) on a UW then BR wire. A ground path for the stage 2 inflator is provided by the control module on a GO then SR wire. The passenger air bag is also provided a ground (C2637) on a B wire.

Passenger Air Bag Deactivation
The passenger air bag can be manually deactivated by turning the switch located on the passenger side of the fascia. A warning indicator is located in the center switch pack of the instrument panel.

WARNING: The manual deactivation feature is not available on North American Specification (NAS) vehicles.

The restraints control module (C1649 & C0256) provides two signal feeds to the passenger air bag cut off switch (C2992) on RU and RY wires respectively. When the switch is in the 'ON' position, the control module registers an earth via the RU wire. When the switch is turned to the 'OFF' position, the control module registers the earth via the RY wire. The switch is provided a ground via a B wire.

When the control module senses the switch has been turned to the 'OFF' position, it deactivates the passenger air bag. It also provides a ground for the warning indicator (C2387) on a G wire. The warning lamp is provided an ignition feed from fuse 68P of the CJB, and illuminates to inform the vehicle occupants that the passenger air bag will not deploy in the event of an accident.

Side Air Bags
A side air bag is attached to the outside of each front seat backrest frame. The restraints control module (C0256) provides a feed to the LH side air bag (C0948) on a WU wire. The LH side air bag is provided a ground path by the control module on an R wire.

The restraints control module (C0256) provides a feed to the RH side air bag (C0949) on a WY wire. The RH side air bag is provided a ground path by the control module on a NY wire.

Side Air Curtains
Five seater vehicles are fitted with LH and RH side air curtains mounted on the cantrails, above the front and rear doors. Seven seater vehicles are fitted with additional side air curtains mounted above the rear quarter windows. The restraints control module (C0256) is connected to the side air curtains as follows:
^ The LH side air curtain (C1479) is provided a feed by the restraints control module on a RW wire. The control module provides a ground path for the LH side air curtain on an BW wire.
^ The RH side air curtain (C1480) is provided a feed by the restraints control module on an BU wire. The control module provides a ground path for the RH side air curtain on a GB wire.
^ The LH rear side air curtain (C2124) is provided a feed by the restraints control module on a BW wire. The control module provides a ground path for the LH rear side air curtain on an GW wire.
^ The RH rear side air curtain (C2125) is provided a feed by the restraints control module on a BY wire. The control module provides a ground path for the RH rear side air curtain on a GY wire.

Pre-tensioners
The pre-tensioners are integral with the seat belt buckles, and are attached to the inboard side of each front seat. The restraints control module (C0256) provides a feed to the drivers pre-tensioner (C2398) on an LGR wire. The pre-tensioner is provided a ground path by the control module on an LGB wire.

The passenger pre-tensioner (C2399) is provided a feed by the control module (C0256) on a YR wire. The control module provides a ground path for the pre-tensioner on a UB wire.

Crash Signal
In the event of an accident severe enough for the restraints control module to deploy the air bags, a 'crash' signal will also be sent to the Engine Control Module (ECM). When the ECM receives this signal it disables the fuel pump. The restraints control module (C1649) is connected to the ECM (C0635 on petrol vehicles, C0872 on diesel vehicles) by a YG wire.

A crash signal is also sent via the high speed CAN bus on YN (high) and YB (low) wires. This message is used by the CJB and Fuel Fired Booster Heater (FFBH).

Diagnostic Socket
The SRS can be diagnosed using T4 via the diagnostic socket. The diagnostic socket (C0040) is connected to the restraints control module (C1649) by a P wire.