Subaru Legacy/Outback

1999-2003 of release

Repair and car operation

System of additional safety (SRS) - the device and a functioning principle

At a head-on collision which sufficiency of intensity the processor (CPU) forward gauges on правленных overloads, and also the managements built in the module control and electric gauges provide short circuit of a chain of activation of face-to-face pillows of safety of the driver and the forward passenger.

Necessary condition for operation of modules of pillows of safety is simultaneous short circuit of both chains built in the module of management SRS of gauges.

Control gauges of lateral pillows of safety are built in corresponding gauges of the directed overloads and work at registration of the directed lateral overloads exceeding certain value, - a simultaneity of operation of the gauge of an overload and the control gauge, besides, is an indispensable condition of activation of a pillow.


The module of management SRS

The module of management SRS is located in a forward part of the tunnel channel of the forward panel of a floor and provides power supplies giving to modules of pillows of safety at the moment of the collision causing strong enough directed overloads. System operation occurs even in case of emergency refusal of the onboard storage battery.

Interrogation of a condition of components SRS is made by the module at each start of the engine and accompanied by short-term operation of the control lamp built in in an instrument guard «AIR BAG/SRS». In case of an exit any of knots out of operation the control lamp after start realisation is not disconnected. Operation of a control lamp testifies to malfunction in system also during movement, - in a similar situation the car should be driven away as soon as possible on a car repair shop.

Gauges SRS

Forward gauges of the directed overloads

Gauges are established ahead of both forward wheel arches. Gauges have a pendular design, анкерный which knot at excess by the directed blow of some limiting admissible value turns and provides short circuit of a corresponding electric chain.

Lateral gauges of the directed overloads

The principle of operation of lateral gauges of the directed overloads is similar described above for forward gauges.

Control and electric gauges

Control and electric gauges are built in the module of management SRS, and also in assemblages of both lateral gauges of the directed overloads.

The control gauge, as well as gauges of the directed overloads, has a pendular design and acts in a role of a safety element at short circuit of corresponding chain SRS.

The electric gauge consists of the semi-conductor element sensitive to directed overloads which resistance changes depending on intensity of blow. The gauge allows CPU to estimate intensity of overloads arising at collision.

Modules of pillows of safety

Design of modules of face-to-face pillows of safety

1 — a safety Pillow 2 — Gazogenerator 3 — the Cover 4 — Gazogenerator 5 — the Bearing beam of a steering column

Pillow activation (ек) safety occurs under condition of simultaneous operation of corresponding gauges SRS (see above). Short circuit of a chain of the module of a pillow of safety leads to almost instant filling with last with the nitrogen allocated as a result of combustion порошкообразной of a mix азида of sodium with оксидом of copper. In case of failure of the onboard storage battery the system is switched to a food from the reserve source built in in module SRS and providing independent development of the electric power during even order of 20 seconds. The design of modules of pillows of safety is presented on illustrations.

Contact drum

The drum is established between a steering column and a steering wheel and represents the sliding contact made of a flat cable vein braided in the form of a spiral. By means of a contact drum giving of a food from a plait of electroconducting of a steering column to placed in a steering wheel nave (and consequently mobile) to the module of a driver's pillow of safety is provided.

Connecting electroconducting

Connecting wires SRS can be easily distinguished from other onboard electroconducting on bright yellow colour of isolation.

Contact sockets SRS are painted in yellow, or dark blue colours (the Section Diagnostics of malfunctions SRS see).

Emergency натяжители seat belts

оцедуры removals/installations emergency натяжителей, and also an order of their recycling are described in Section Seat belts - the general information, condition check, removal and installation, an order of recycling not worked emergency натяжителей.

Seat belts of both forward seats are equipped automatic emergency натяжителями which activation occurs at the command of the module of management SRS, developed on the basis of the analysis of the data arriving from forward gauges of directed overloads (under condition of short circuit of the built in control gauges). A design basis натяжителей make equipped built in газогенераторами assemblages of belts of returnable drums taking up tape.

Design emergency натяжителя a seat belt

1 — the Seat belt 2 — the Returnable device 3 — Leading up laths	4 — the Shaft 5 — Gas 6 — Torsionnaja a bar

At receipt of a corresponding command from the module of management SRS газогенераторы натяжителей are activated also a weak point of seat belts instantly gets out returnable devices. At excess by loading on a belt of some limiting admissible value built in assemblage натяжителя торсионная the bar is braided, weakening thereby the influence rendered by a tape of a belt on a thorax of the fastened driver/passenger.

On termination of operation emergency натяжителя the returnable drum remains is blocked also seat belt assemblage is subject to replacement.

Safety measures

Check of condition SRS should be made time of 10 years.

Dismantle and service of components of a steering column, radio receiver and the other components located near to the panel of devices demands observance of special safety measures as casual damage of electroconducting SRS can lead to unapproved operation of pillows of the safety, fraught with reception of serious traumas. Electroconducting SRS is easy for identifying on bright yellow colouring of isolation, - at all do not disunite its contact sockets and do not connect to them any electric diagnostic devices.

Before to start performance of any works near to components SRS in necessarily order disconnect system!

The module of a pillow of safety removed from the car should be held a face sheet from itself, - transfer assemblage to a safe place and lay a face sheet upwards.

Do not try to make at all measurement of resistance of components SRS, - developed by the internal power supply of an ohmmeter of energy can quite enough for operation газогенераторов!

Before to use on the car any electronic equipment it is necessary to make necessarily switching-off SRS (see more low).

At all do not throw out never worked modules of pillows of safety in мусороприемники, - consultations on recycling of components SRS always can be received on car repair shops.

System SRS switching-off

For switching-off SRS make following manipulations:

a) Result operated wheels of the car in rectilinear position, turn the ignition key in position LOCK and take it from the lock;
b) Switch off ignition;
c) Disconnect from the battery at first negative, then positive wires.

If the stereosystem established on the car is equipped by a security code before to disconnect the battery make sure that have a correct combination for audiosystem input in action!

d) Before to start performance of any works, wait not less than 20 seconds during which there should be a discharge of the condenser of emergency power supply SRS.

Activation SRS

For system activation connect to the battery at first a positive wire, then - negative, turn the ignition key in position and make sure of serviceability of operation of control lamp SRS.