12:10. System of additional safety (SRS)

All models considered in the present manual are equipped with system of additional safety (SRS). Four are a part of system (two frontal and two side) safety cushions, and also emergency natyazhitel of seat belts of front seats. The system provides additional protection of the driver and forward passenger of the car at strong frontal and side blows, and also when capsizing the car (depending on a complete set). A brain of system is the SRS control unit including contours of self-diagnostics and feedback (see the illustration Scheme of an Arrangement of Control Units of Various Systems on the Infiniti QX4 cars), the nervous terminations — sensors of the directed overloads and the control sensor in the block.


Principle of functioning


Scheme of activation of frontal safety cushions and emergency natyazhitel of belts


Scheme of activation of side safety cushions and emergency natyazhitel of belts

Necessary condition of activation of safety cushions and emergency natyazhitel of belts is operation of sensors of the directed overloads and the control sensor. Operation of sensors leads to short circuit of a chain of modules and instant filling of pillows with gas, and also to activation of pyros of emergency natyazhitel (see the illustrations Scheme of Activation of Frontal Safety Cushions and Emergency Natyazhitel of Belts and Scheme of Activation of Side Safety Cushions and Emergency Natyazhitel of Belts ). In case of failure of the battery operation of elements of system happens due to the energy developed by the feedback knot which is built in in the SRS block.

Operation of frontal safety cushions and emergency natyazhitel of belts happens only at head-on collisions in borders of the 30-degree sector and at a relative speed of the movement not less than 30 km/h.


System of self-diagnostics of refusals of SRS

The system of self-diagnostics of SRS makes inclusion of a control lamp on an instrument guard of the car at turn of the ignition key in position of ON. If the system does not find any deviations, the lamp has to go out about 6 seconds later. If shutdown of a control lamp does not happen, or the lamp works during the movement of the car, therefore, in the SRS system malfunction is found. The corresponding diagnostic codes register in memory of the onboard processor and their reading can be made by means of the special reader of the skanerny type connected to the car DLC socket (see the Head of the Feed and control system). For check of system and elimination of the reasons established refusals the car it is necessary to drive away on car repair shop.


Service of the knots located near the SRS components

In case of need removals of a steering wheel, or carrying out service of the radio receiver or another, located near the dashboard components try not to allow rassoyedineniye of electric sockets of a chain of SRS. Do not connect any diagnostic equipment to SRS chain at all! AT SERVICE of the SAFETY CUSHIONS of ALL COMPONENTS LOCATED CLOSE ALWAYS PREVIOUSLY DISCONNECT SRS (see below).

It is easy to distinguish an electrical wiring of a chain of SRS on bright yellow color of isolation.


Shutdown of the SRS system

The SRS system has to be disconnected every time at performing procedures of service of the safety cushions of components located close!


 PERFORMANCE ORDER

  1. Switch off ignition and all onboard consumers of the electric power. Disconnect from the battery at first a negative wire, then positive. Before starting service of components, wait not less than 1 minute during which the condenser of the emergency SRS power supply has to be discharged.

If the stereosystem established on the car is equipped with a security code before disconnecting the battery make sure that you have the correct combination for input of the audio system in action!


Precautionary measures


Precautionary measures of the general character

The listed below precautionary measures have to be taken before performance of any works on service of the cars equipped with the SRS system.


The precautionary measures necessary at the address with safety cushions


Precautionary measures at storage of safety cushions