Today, airbags are an integral part of the security system of any vehicle. They are needed in order to protect both the driver and passengers of the vehicle during the movement. Therefore, the car owner needs to periodically check the performance of this system. In particular, monitor the condition of the airbag crash sensors. We will talk about their features, functions. We will also figure out how to find out that the PB is faulty.
PD requirements
The airbags installed in the vehicle must meet the following minimum set of requirements:
- Must be filled with gas composition at a certain speed.
- The gas must also leave the PD at a certain rate.
- The pillow should have a volume that ensures passenger safety.
- The device must be of the required shape, geometry.
- The correct arrangement of airbags in the passenger compartment.
- Inflating pillows at certain points.
Required Items
Car airbags are a combination of the following elements:
- Cushion shell.
- The gas composition with which it is filled.
- Gas-forming substances.
- Side airbag crash sensor G179.
- Car seat position sensor
- The driver's side airbag shock sensor G179.
- Passenger seat sensor.
- Impact sensors PB located along the windshield and so on.
- The electronic control unit for this security system.
System
Airbag shock sensors are not separate elements. They are part of the SRS system. It includes the following:
- The main control device.
- PB (airbags themselves).
- Controllers.
- Actuators - from the pyro-cartridges of the PB to the relay that turns off the fuel pump.
Varieties
Airbag shock sensors are not the only SRS sensors. It is assumed that they work systemically with other elements. The following stand out here:
- Airbag crash sensor.
- Passenger presence sensor in a vehicle.
- Satellite sensor.
Get to know them in more detail.
Shock sensor
Many car owners wonder where the airbag shock sensors are. But not everyone knows their purpose.
It also consists in determining the collision and transferring the corresponding impulse to the control device of the system. The design of such a sensor can be very different. It depends on the model of a particular car.
A common example is an electromechanical controller. Accordingly, in a certain situation, he will close his contacts. What happens next? When the contacts are closed, current flows through them. As a result, this triggers actuators. They already initiate the filling of airbags with a special gas composition.
We examined how the airbag shock sensor works. But we must remember that only a strong blow is needed to initiate his actions. Only then will the process be started.
In the event that at the time of a traffic accident there will be a violation in the power supply of the battery, the safety devices will still work - they will be filled with gas. What is the reason for this? In the system there is a special capacitor device that can accumulate a charge in itself.
Sensor Location
So where are the airbag shock sensors? It all depends on the model of a particular car. The most common examples of controller locations are here:
- Airbag control device.
- Inside the cabin.
- In some cases, in the engine compartment of a car.
Where are the airbag shock sensors? In the case of foreign cars, there is another additional shock sensor - already to turn off the fuel pump. It often acts as the cause of problems - with a minor impact, the airbags do not work, but at the same time, the car cannot be started until this sensor is activated.
Passenger presence sensor
Now you know the location of the airbag shock sensors. We proceed to consider the following variety.
The speed with which the airbag is fully inflated depends on the mass of the person sitting in the car seat. Its regulation in case of a car collision is necessary for the quick and timely creation of a gas layer between the passenger and the center console (in case of a head-on collision). If the collision is lateral, accordingly, the system needs to create a gas layer between the door and the glass.
To perform these functions, the security system focuses primarily on the weight of the passenger. The impact force is determined taking into account the elasticity of the airbags themselves.
As for the sensors for the presence of passengers, they are located in all cars directly under the seats.
Sensor Issues
People presence sensors in car seats are often a problem for vehicle owners. The most common is a decrease in the sensitivity of their controllers. So, if a child is in the passenger seat, the system may simply not determine its presence due to its low weight. And this is fraught with the fact that in a collision, airbags may simply not be filled with gas.
There is a flip side to the problem. If the weight of the child is determined by such controllers incorrectly, then the system will begin to inflate the PB at a speed too large for its mass. This can lead to injury to the baby.
Violation of the integrity of the PB
Car owners should be aware of how to check the airbag shock sensor. Indeed, the safety of their life depends on its serviceability.
In most cases, the system itself "tells" the car owner that something is wrong with her. The Airbag or SRS indicator on the dashboard lights up. The most common cause of such a problem is a violation of the integrity of the PB.
Because of this, the control device no longer receives impulses from shock sensors, other controllers, seat belts and other system components. In some cars, the belts themselves are equipped with sensors that can determine whether they are fastened or not. Therefore, if the driver or passenger forgot to fasten their seatbelt, the indicator will also light, signaling a mess with the system.
The fact is that the operation of the safety device is relevant in the case when people in the car are strapped in. Otherwise, if the driver does not fasten his seat belts and gets into a traffic accident, the safety instructions will fly out at a speed of 200 km / h. And this is already traumatic for humans. Collision with pillows in this case can be compared with a blow to a concrete fence at a speed of 25 km / h!
Fastening - not fastening of belts
I must say that this moment with fastening-non-fastening belts took into account many car manufacturers. The problem was solved simply: in the event of an accident, and people in the car are not fastened, the safety devices simply do not work. Here the system cannot guarantee you any security at all.
There are cases when drivers intentionally deceive the security system, stretching belts behind the backs of the seats, installing emulators, but really not fastening their seat belts. Accordingly, the system begins to "think" that people are fastened and in the event of an accident, with a maximum speed throws out the safety net.
Such tricks are dangerous. Yes, you will ensure that the indicator on the panel stops lighting in the case of unfastened belts. But in an accident in this case, you will significantly reduce the chances of survival - both for yourself and for your passengers.
Other causes of malfunctions and their solution
We will analyze the main causes of problems, malfunctions associated with the car security system, imagine ways to solve them:
- Bad connection of elements in the power circuit of the power plant or lack of contacts. Another reason for the constant glow of the malfunction indicator is a poor connection of the system connectors. The solution is to check all the contacts, as well as the quality of the connection.
- Failure of shock controllers is another common cause of the glow of indicators on the dashboard. Perhaps they are poorly connected. Check not only the quality of the connection of the network elements, but also the connectors. What to do if all contacts are working? If the indicator on the "tidy" continues to signal a malfunction of the shock sensors, it means that these devices must be replaced as soon as possible. Otherwise, the presence of PB in your car can be considered useless - they will not respond to the blow. How to check the airbag sensor with a multimeter, the instructions for the device say.
- The next common cause of a malfunctioning car security system is a broken contact in the door. In most cases, this is the result of repair work or replacing doors in the car. During this, as a rule, the connectors are disconnected. Therefore, at their subsequent connection, all contacts must be checked. If the indicator in this case continues to light even after reconnecting, then there is only one way out: reset the memory of the security control device.
- Another cause of malfunction is moisture. It can be on the contacts of electrical elements, on the locks of seat belts. This leads either to poor contact, or even to short circuit. What to do with such a problem? The place where you find moisture must be thoroughly dried.
- Incorrect operation of the control unit, its failure. The reason may be simple - the contacts are gone. But if the essence of the malfunction lies in the device board, then the problem is solved radically - by replacing this unit.
- Safety elements. If such devices fail, the indicator on the "tidy" will also light up. The problem is quite common, as not many car owners pay due attention to fuses.
- Replacing control panel or car seats. This can also lead to a malfunction of the machine's security system. The reason is that when replacing, the integrity of the wiring may be damaged. In particular, joints may suffer.
- A similar malfunction in some cases also occurs when replacing the steering wheel. In particular, in cases when during such repairs the contacts of the security system are damaged. There is already an indicator of a malfunction of the security system will remain on, without stopping.
- If airbags were triggered during a road accident, then the PB malfunction indicator in some cases continues to light even after the airbags are restored. This indicates that the incident information remained in the memory of the control unit. You can solve the situation by removing this error from there.
- The operating life of airbags is also the reason for the activation of the malfunction indicator. Remember that the average life of a safety device is 8-10 years. If it is exceeded, manufacturers of such systems cannot guarantee the operability of their products.
- Low voltage in the vehicle electrical system. How to solve a problem? First, check the battery, and then the generator.
Thus, the shock sensor is an integral part of the security system. If it malfunctions, the PB will not open at the right time. Therefore, car owners should periodically check its performance. As well as the proper functioning of all other elements of this system. Indeed, the life safety of the driver and passengers of the vehicle depends on it.