Subaru Forester

1997-2005 of release

Repair and car operation

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

The general information

Some of models considered in the present Management are equipped by system of additional safety (SRS), more known under the name of pillows of safety. The system provides additional protection of the driver and the forward passenger of the car at strong front and (at a corresponding complete set) lateral blows. The module of a driver's face-to-face pillow of safety is placed inside ступичной parts of assemblage of a steering wheel (the Suspension bracket and a steering see the Head).

The module of a passenger pillow of safety is located on the right under the panel of devices of the car on which surface the warning inscription in the form of abbreviation SRS or AIR BAG is thus put. Lateral pillows of safety (at a corresponding complete set of the car) are built in in external lateral walls of backs of forward seats.

Control lamp SRS/AIR BAG, spring contact drum of assemblage concern number of other components SRS подрулевых switches, the management module (ECU) SRS with built in in it the gauge of the directed overloads (G-gauge) and the control gauge, individual gauges of the directed overloads of pillows of safety and connecting electroconducting.

The scheme an arrangement of components SRS

1  —  Assemblage combined подрулевых switches with a spring contact drum
2  —  Fixing bolts with heads of type TORX (Т30)
3  — the  Module of a driver's pillow of safety
4  — the  Module of a passenger pillow of safety
5  — the  Module of management SRS
6  —  Fixing bolts with heads of type TORX (Т40)
7  — the  Gauge of a lateral pillow of safety
8  — the  Module of a lateral pillow of safety

9  —  Electroconducting of a chain of the left lateral pillow of safety
10  —  Electroconducting of a chain of the right lateral pillow of safety
11  — the  Main plait of electroconducting SRS
12  — the  Gauge of the right forward pillow of safety
13  —  Electroconducting of a chain of the right forward pillow of safety
14  —  Electroconducting of a chain of the left forward pillow of safety
15  — the  Gauge of the left forward pillow of safety

Principle of functioning SRS

At strong front blow of the car gauges of forward pillows of safety, and also built in in ECU SRS the G-gauge and the control gauge provide short circuit of a chain of activation of pillows.

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

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

Modules of pillows of safety

Pillow activation (ек) safety occurs under condition of operation of gauges of directed overloads SRS. 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 within even 20 seconds. It is necessary to notice that the passenger pillow of safety usually is more on volume, than driver's, and is equipped by the metal bearing case, at module operation divided into two half, and a finishing cover.

Spring contact drum

The drum is established on steering columns and represents contact in the form of a spiral spring. By means of a contact drum giving 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.

The management module

ECU SRS 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 built in in the panel of devices of the car of a control lamp “AIR BAG/SRS”. In case of an exit any of knots out of operation switching-off of a control lamp do not occur. 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.

Safety measures

Check of condition SRS should be made time in 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 of pillows of safety make following manipulations:

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

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!

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.