15.23. Safety cushions (SRS)
On cars the auxiliary system of safety (is established to SRS – Supplemental Restrain System) better known as safety cushions. The system consists of the sensors established from the forward party of the car, safety cushions and the control unit and diagnostics. On the car the system of safety cushions of the HAE-3 type is established. The HAE-3 system can be established in various executions of DAB + 2 BPT, DAB + to PAB + 2 BPT, DAB + by PAB + 2 BPT + 2 FSAB (DAB – a safety cushion of the driver, PAB – a safety cushion of the forward passenger, BPT – a natyazhitel of a seat belt, FSAB – a lateral safety cushion).
SRS consists from: the air chamber from the driver located in the center of a steering wheel and containing the curtailed pillow and the block of a gas generator; the air chamber from the forward passenger, located in the dashboard and containing the curtailed pillow and the gas generator block; lateral air chambers located in backs of the driver and the forward passenger both containing the curtailed pillows and the gas generator block. The SRSCM control unit is located on a car floor under a radiator of a heater and supervises system of safety cushions and includes: the accelerometer which defines car delay; the spiral wire (spring) located in a steering column; electric chains and sockets; the knee buffer located under a steering column. The spiral wire transmits a signal irrespective of the provision of a steering wheel.
The collision moment defines the SRSCM block on the basis of information from the accelerometer which constantly supervises car acceleration.
Deployment of a safety cushion occurs at front or nearly a head-on collision to moderate or big effort.
The pyrotechnic gas generator will transform an operating electric signal to an ignition signal therefore the powder decays, inflating a safety cushion bag.
For service of safety cushions or the SRS components specially trained personnel should be allowed only. At service of SRS it is necessary to show extreme care to avoid a personnel travmirovaniye at unauthorized expansion of safety cushions of the driver or the forward passenger.
At violation of sequence of shutdown or service of system of safety cushions can occur unauthorized expansion of safety cushions and drawing of serious injuries. Also, unqualified service of system of safety cushions can lead to that the safety cushion will not work at collision.
Before service performance, including removal or installation of elements of system, carefully carry out the following recommendations.
- Before service of system of safety cushions be convinced that passed not less than 30 with the ambassador of switching off of ignition and a wire detachment from the negative plug of the storage battery. The system of safety cushions is equipped with an emergency power source which allows to develop safety cushions in case of a detachment of wires from the storage battery at failure. Time during which the emergency power source provides with energy system of safety cushions, makes 150 ms.
- At a wire detachment from the negative plug of the storage battery memory of hours and sound systems is erased. Before the beginning of work take information from sound systems. After the completion of works establish time on hours and carry out repeated installation of sound systems.
- Signs of failure of system of airbags of safety are difficult for checking, so diagnostic codes become the most important source of information by search of malfunctions.
- By search of malfunctions of system of airbags of safety before a detachment of the storage battery check the codes of malfunctions brought in memory.
- Do not use spare parts of safety cushions from other cars.
- Do not assort and do not repair elements of system of airbags of safety.
- If any SRS component fell or on it there are cracks, dents or other defects in the case, an arm or the socket, replace them with the new.
- After work execute check of system of airbags of safety.
In certain cases the electric chain of a control lamp of safety cushions can be broken by other malfunction of a chain. Therefore, if the control lamp of safety cushions constantly burns, check that, all DTC codes are erased from memory.
- At carrying out electrowelding works surely disconnect a wire from the negative plug of the storage battery.