Mercedes M-Class W163

since 1997 release

Repair and operation of the car

System of additional safety (SRS)

Enter number of the devices and components forming system of additional safety (SRS):

1. Two forward (frontal) safety cushions. The module of a driver's safety cushion is placed in a nave of a steering wheel. The safety cushion of the forward passenger is placed in a special cavity in the right part of the dashboard of the car. The locations of both pillows are marked with the precautionary inscriptions "SRS AIRBAG";
2. Four side safety cushions of front and back seats. Modules of side safety cushions are built in at the corresponding doors of the car;
3. The head pillows (curtains) of safety placed along side edges of the ceiling panel and providing additional protection of the heads of the driver and all passengers at side blows and a turning of the car;
4. The sensors of the directed overloads working at strong front/side blow;
5. Electronic system of self-diagnostics which at the included ignition provides continuous testing of sensors of overloads, the control unit, gas generators of pillows and a connecting electrical wiring of the corresponding chains;
6. The automatic emergency natyazhitel of seat belts who are built in in returnable devices of seat belts of front seats;
7. The control lamp of refusals of SRS which is built in in the dashboard;
8. The spare independent power supply intended for duplication of the main power supply system in case of its exit out of operation during collision.

In an instrument guard of the car the special control lamp of SRS (see the Section Combination of Devices, measuring instruments and control lamps and light indicators) intended for the warning of the driver of the refusals revealed by system of self-diagnostics in system of additional safety is built in. Depending on a car complete set operation of a control lamp testifies to possible malfunctions of modules of frontal/side safety cushions or devices of an automatic emergency tension of seat belts.

Principle of functioning of frontal safety cushions

Modules of frontal safety cushions are built in in a stupichny part of a steering wheel and in the panel the right part of the dashboard, directly over the main ware box.

Sensors of the directed overloads react to excess of some extreme value which can arise at strong head-on collision. On a signal of sensors the control unit includes gas generators of safety cushions, causing their instant filling.

During collision the seat belt holds the lower part of the trunk sitting from shift. Forward safety cushions help to prevent traumatizing the driver and forward passenger as a result of blow by their head and a thorax about a steering wheel / dashboard.

As signals on operation of both safety cushions arrive from the same sensors, both pillows work at the same time. However the probability of initiation of only one of pillows is not excluded. It becomes possible when the size of the directed overloads which arose at collision was on the verge of the range of sensitivity of sensors. In this case seat belts provide rather reliable protection of the driver and forward passenger while the effect of operation of a safety cushion is minimum.

Right after operation and performance by pillows of the functions gas from them is produced that allows the driver to keep visibility and to manipulate freely all governing bodies of the car.

The full duration of process takes with sensors of overloads before production of gas from pillows fractions of a second the moment of giving of a signal. Operation of pillows happens so quickly that the human ear simply is not capable to apprehend cotton of gas generators when filling pillows.

After the road accident at which there was an operation of safety cushions the volume of interior of the car looks slightly smoke-filled. Actually it is a suspension of fine powder which usually pours covers of pillows in the put state. People with a disease of respiratory organs can feel a certain discomfort from the gaseous products which are contained in air allocated by gas generators of pillows.

Principle of functioning of side and head safety cushions

Modules of side safety cushions are built in in the panel of side doors of the car. The locations of both side pillows are usually marked with the inscriptions "SIDE AIRBAG".

Gas generators of head pillows are located on side edges of the ceiling panel.

At strong side blow sensors of the directed overloads fix excess by the arising loadings of some threshold value and give information signal on the control unit which develops the command for operations of a gas generator of the corresponding side safety cushion. At the same time, if the blow was come from the outside a passenger seat, the corresponding side pillow will work even at absence on the passenger's seat.

For ensuring the greatest efficiency of protection which is provided by safety cushions the driver and the passenger sitting on a front seat have to sit directly and to be fastened by seat belts.

Order of functioning of a control lamp of refusals of SRS

At inclusion of ignition (the ignition key is turned in situation 2) the control lamp lights up for a short time, then at once dies away that confirms about serviceability of functioning of all knots of system.

At any operation of a control lamp at any other moment follows the owner of the car at the first opportunity to ask for the help specialists of car repair shop of the Mercedes-Benz company. The following is among such situations:

1. The control lamp does not join at turn of the ignition key in situation 2;
2. The control lamp continues to burn after implementation of start of the engine;
3. The control lamp is activated and burns in the constant or flashing mode during the movement of the car.

In the presence of the listed above malfunction signs the additional security system can refuse at failure of the car.

Seat belts with automatic emergency natyazhitel

Emergency automatic natyazhitel equipped returnable devices of three-anchor seat belts of front seats and side places of a back seat of the second row. Are put by Natyazhiteli in action at the strong frontal overloads arising at head-on collision and provide instant selection of a weak point of belts therefore tapes of the last densely cover a body sitting, in considerably degree increasing degree of protection of the driver and forward passenger.

Natyazhitel (A) is built in in assembly of the returnable mechanism of a belt. The order of use of such seat belts is similar to an order of use of the usual belts equipped with inertial returnable devices. The mechanism of operation of a natyazhitel is absolutely transparent for the user and does not demand from the last any additional skills and knowledge.

Activation of natyazhitel happens only at considerable frontal overloads. Operation of modules is followed by loud cotton and small smoking.

It is necessary to notice that refusals of operation of natyazhitel at head-on collision in most cases are explained not by malfunction of system, and the fact that the overloads arising at blow do not reach threshold value at which activation of modules is made.

As well as in case of safety cushions, modules of emergency natyazhitel are calculated on single operation and after that are subject to replacement assembled with belts, - address on company car repair shops of the Mercedes-Benz company. In the same place all claims concerning refusals of the SRS components are accepted.

Maintenance of the SRS elements

Safety cushions and devices of an automatic emergency tension of seat belts, practically do not need regular checks and maintenance. However the owner of the vehicle equipped as appropriate has to mean the next moments:

1. After operation of safety cushions they are subject to obligatory replacement together with the system control unit. Do not try to dismantle the fulfilled pillows independently. These operations have to be carried out only in the conditions of a workshop of car service;
2. If operation of a control lamp of SRS indicates existence of refusal in system, it is necessary to address immediately on the nearest car repair shop of the Mercedes-Benz company where full diagnostics and necessary recovery repair of system will be made. Otherwise safety cushions can not work at the road accident and not execute the protective function;
3. Only specially trained personnel are allowed to works with knots of an additional security system. It is forbidden to dismantle independently from the car of a safety cushion and emergency natyazhitel of seat belts. In case of refusal SRS or after emergency operation of safety cushions and natyazhitel of seat belts needs to address on car repair shop of the Mercedes-Benz company for carrying out repair or replacement of knots of system;
4. Do not open modules and do not change an electrical wiring of systems of safety cushions and devices of an automatic emergency tension of seat belts, - such intervention can lead to involuntary operation of pillows and natyazhitel and to be the reason of traumatizing the performer or the people who are nearby;
5. You do not make replacement of front seats without receiving preliminary consultation at car repair shop of the Mercedes-Benz company. Inaccurate or incorrect performance of replacement or removal of covers can lead to refusal of operation of side safety cushions in case of the road accident.

By transfer of the car to other person it is necessary to inform without fail the last on all established SRS elements with the indication of the corresponding points of the instruction on rules of use of the car.

On all equipped SRS models in locations of active elements systems are installed the special warning plates.