Safety is an important part and airbags play a very high role in it. Here we will discuss how to replace them. We have to do this either because of a malfunction, or because an accident has already happened, the airbags have fired and now we need to install new ones.
Many drivers are confident that the airbags will work even in a minor collision, but in fact they will only work in a hard collision at a speed above 30 km/h. The point is that there are negative sensors that control the shot.
In general, the entire mechanism consists of a large number of sensors, so you will not be able to replace only the fabric; you will have to change some sensors.
Adviсe
If you have a good understanding of cars, and most importantly, electronics, then you can do this, but if you have little knowledge, then it’s better to contact a service center. The fact is that you will have to work with sensors and do firmware.
You will also need to flash the on-board computer, which remembers the impact and stores it in its memory. In some models, the gearbox goes into emergency mode, and some are flashed only to say on the secondary market that the car is not damaged.
We'll talk about replacing front airbags, which are most often deployed in front or rear impacts. These types of accidents occur most often and therefore we will discuss this particular type of airbag.
Possible malfunctions of the power supply unit
An indicator on the dashboard indicating a malfunction of the power supply unit notifies you of the following symptoms:
- airbags are damaged;
- the shock sensors are faulty;
- the connectors do not make good contact with each other;
- block damage;
- The devices have reached their service life.
The main problem is the wiring.
If the airbags have deployed, they can be replaced or revived. More details below.
Changing the driver's airbag
Changing the steering wheel is not that difficult, but before doing this you need to disconnect the terminals from the battery. Firstly, this will ensure the safety of work, and secondly, the sensor will be turned off and the on-board computer will not think that removal was carried out.
Otherwise, the on-board driver will record an error. Your task is to remove the central part of the steering column, disconnect all the contacts and remove the cushions, and therefore install a new one in the reverse order.
Is it possible to restore it with your own hands?
Having purchased the necessary kit, you can independently restore all the parts of the SRS system in a garage.
New airbags require seat belts and sensors. However, after successful installation of all components, the control unit will display an Airbag error, since information about the collision remains in its memory.
Not all airbag ECUs can be reflashed. More often, the element is changed along with a new set of PBs. But custom blocks still need to be shown to specialists.
Change the passenger airbag
Here everything is a little more complicated, the fact is that in most cars the airbag is located behind the dashboard panel. Most often, after a shot, the casing deteriorates. On some cars, the system is attached to the car frame and to replace it you have to remove the dashboard panel.
The first thing you need to do is remove the cover from the steering wheel and remove the airbags, even if they are in good condition. You also need to unscrew the mounting bolt and remove the steering wheel itself. Afterwards, you can see a few more bolts above the pedals; they also need to be unscrewed, this will give you the opportunity to get to the center console.
Next, you need to release the latches using a screwdriver on the center console. This will help you remove the head unit and everything else. After disconnecting all this, you can remove the dashboard panel, but you need to do this carefully.
If the panel was damaged, and this happens on some cars, then unfortunately you will have to replace the panel. In this case, we will only consider replacing the pillow if the panel is intact. It is necessary to remove the panel carefully so as not to damage it, fasteners and the pillow itself. If you have a foreign car, then there will be a lot of fasteners, keep an eye on this.
It is advisable to do everything in a garage with lighting, since the procedure is not quick, sometimes you will have to spend a couple of days. It’s also worth remembering that after an accident you have damage to the body that also needs to be fixed, but more on that later.
Remember, seat belts, windshield and some other car parts most likely require repair.
Your task is to remove, disconnect all suitable wires and dismantle the mechanism itself. Then you need to install everything new, but in reverse order. But it’s worth remembering that it’s not worth getting into if you don’t understand car electronics.
Operating principle
The AirBag is made of fabric with nylon elements. Thanks to special holes through which gas escapes, the product can be softened, which reduces the likelihood of injury. A gas generator is attached to each part, then the product is carefully folded and placed in small holes in different places of the car. As for the steering wheel, the gasifier is equipped with a rubber ring for optimal balancing.
The gas generator, by the way, fills the pillows with gas and introduces a quick release. It is considered the most complex in technical and constructive terms. Airbags inflate at extremely high speeds, with a deployment speed three times faster than the blink of the human eye. As for the principle of operation, they are triggered at the moment of collision if the vehicle speed exceeds 20 km/h.
The operating principle of an airbag consists of the following stages:
- On opposite sides of the machine there are special sensors that react to a given critical moment.
- This information is transmitted to the ECU, which processes it. The circumstances for this are more than specific - overcoming a high obstacle in the form of a curb, a sharp landing or a head-on collision.
- The signal from the ECU is sent to the gas generator and the pyrotechnic charge is activated.
- After combustion of the squib, excess nitrogen is released as the generator gas picks up sodium acid. It is nitrogen that activates the cushions.
How much is it?
All this will not be cheap; on average, a pillow costs 15,000 rubles for both driver and passenger. Of course, if you have an old car or a very budget one, everything will cost much less.
Also, all the necessary work can be done at a service center; the replacement procedure itself will cost about 5,000 rubles, also depending on the car.
How to check the sensor if the airbag light on the dashboard is on
Nowadays, the most frequently reported breakdowns in cars are the passenger presence sensor on the seat and the spiral PB sensor located in the steering wheel. The job of the first one is to establish the weight of the person who occupies the seat. This parameter allows the device to calculate the approximate age of the passenger.
Technology that allows one to determine a person’s age by weight is used in vehicles for a reason. The security system receives a signal and the front airbag is automatically switched off in cases where a child occupies the seat in front. Due to the small stature of children, anterior spinal cord is very dangerous for them. The impact of a deployed airbag can even cause the death of a child.
Unfortunately, the sensor that determines the passenger's weight begins to work worse and worse over time. It stops functioning due to the seat being moved too often. Such manipulations easily damage the device itself or the wires. If we take into account that the airbag control system continuously monitors the status of all sensors, then if one of them malfunctions, the light immediately starts to light. This indicator indicates that the passive safety system is faulty.
In some cars, the owner can disable the front passenger airbag with his own hands. This is also one of the reasons why the airbag light on the instrument panel may be on. An interesting fact is that if the PB was intentionally turned off, but an adult sat in the chair, it is automatically activated.
When the airbag deactivated light comes on but there is an adult in the seat in front, one of the SRS devices is faulty. Then you should first make sure that the wires under the front passenger seat are intact. If you find damage to the wiring or establish that the “weight sensor” is completely inoperative, it is worth replacing it with a new one.
Another common SRS problem is a malfunction of the airbag spiral sensor. It is located between the steering wheel and steering column. Due to the fact that the device is connected to the board, different buttons on the steering wheel can work. However, this unit also often wears out, causing the buttons on the steering wheel to stop functioning and the driver’s power steering switch to turn off. To fix everything, you need to replace the part by removing the steering wheel.
Before you begin repairing the unit, you must first remove the negative terminal of the wire from the battery and let the batteries discharge for 10–15 minutes.
- Every car has shock sensors, the number of which depends on the model. These devices are needed to detect a collision. When such devices do not function, the light on the panel also starts to light, indicating an error.
- To ensure that the airbags do not deploy when the seat belt is not fastened, seat belt buckle sensors are used. However, with any manipulation of the lock and if water gets in there, problems occur in the system. An error signal is displayed accordingly on the instrument panel.
To understand what exactly is faulty, a diagnostic scanner is also used.
Let's move on
So, you have installed everything, but there is no need to assemble the dashboard panel, because your task is still to work on the on-board computer. You can just buy a new one, it will cost you about 50,000 rubles, but it’s a little expensive. You can go to a service center and flash an old computer; it will cost 5 times less, but there is no guarantee that everything will be fine.
As a result, the cost of all procedures in total is quite high, if you do everything to the minimum, then everything will cost about 50,000 rubles, and if you do everything efficiently, it can easily go over 100 thousand.
Dismantling technology
Whatever repair option you choose, you will have to remove the pillow. Often the steering wheel does not interfere with comfortable work and there is no need to remove it. Let's consider the step-by-step technology using the example of several brands of vehicles.
Lada Priora
Sequencing:
- First disconnect the battery and wait 10 minutes until the AirBag activator capacitor is discharged.
- The steering wheel should be level. If this is not the case, correct the wheel position and remove the ignition key.
- To secure the airbag, a bolt is used, which can be easily removed with a hexagon. There is also a screw on the other side, and you can get rid of it in the same way.
- Move the airbag module away from the steering wheel.
- The next step is to lift the wires and the pad clamp, and turn off the pad.
- At the final stage, the AirBag can be removed and stored, if necessary, with the cover facing up in a cool, dry place.
Toyota
There are no significant differences in technology between domestic cars and foreign cars, but it is worth paying attention to the mounting of the module and the system itself in the steering wheel. Using the example of a Toyota car, we can analyze this difference in more detail.
The process consists of the following steps:
After completing all the mentioned preliminary work, get rid of the plugs, which play the role of decorative equipment. You will find them on both sides of the steering wheel. Use a screwdriver to remove the bolts. Even when you completely unscrew the screws, you will not be able to remove the AirBag yet, since the bolts are located in plastic holders
Once unscrewed, the screw should be pulled out with the utmost care. To remove the airbag module, a certain amount of force must also be applied. At this time, you must disconnect the corresponding wires. When assembling, follow the reverse procedure.
Ford Focus
In the case of this brand of vehicle, the technology looks like this:
- after turning off the power supply and waiting 10 minutes, remove the top cover, which acts as a lining of the steering column;
- turn the steering wheel 180 degrees, after which you can disconnect the latches and unscrew the fixing bolts;
- after turning the steering wheel at a right angle, repeat the same actions on the opposite side;
- release the latches by slightly picking up the steering wheel trim;
- disconnect the block and remove all wires from the steering trim, after which you can remove the cushion.
Smart
In this case, it is impossible to do without dismantling the steering wheel. Deactivate the battery first, otherwise you risk getting into a situation where the airbag goes off at the wrong time.
Next we perform the following steps:
- The only fastening element that will need to be unscrewed at the first stage is located below under the steering column cover.
- To remove the steering wheel you will have to apply a little force and pull it towards you. For final dismantling, do not forget to disconnect the wires that go to the ESP and the pillow.
- After dismantling, position the steering wheel face down. The surface must be clean and level. Special clips secure the plastic casing that needs to be removed.
- After completing this task, you will be able to locate where the panels are fixed. Get rid of three fixing parts and clips. Next, move on to the two bolts on the back side and you can remove the cushion.
- Inside the steering wheel you will find not only a cushion, but also a cartridge with wires. Be sure to unplug the yellow connector.
Self-firmware
In order to do this, you need to take a computer; a laptop will be much more convenient. You will also need to buy or somehow find software for your car. And you will also need a special cable.
It’s better, of course, not to do this, since the cable costs about 3 thousand, and the software is also not cheap. If you still have all this, then, of course, it will be cheaper to do it yourself, but if not, then it’s better to go to a service center.
Your task is simply to replace the old program with a new one, but if you have a new car, then it would be much more correct to install a new on-board driver. The fact is that the regulation sensor is disposable and it is not a fact that everything will be perfect when flashing the old one. To check, you can connect the old airbags and see if the error icon on the instrument panel disappears; if so, then you can connect new ones.
If you do not check the system as described above, then there is a chance that when you connect new ones they will immediately fire and you will have to change them again, and all this is expensive.
Differences between the Chinese train and the original one
The Chinese-made Nissan Qashqai steering column cable differs from the original part. This fact must be kept in mind when purchasing cheap spare parts. Firstly, the product from China does not have a tap responsible for the operation of cruise control. If the crossover does not have this option, the choice in favor of a Chinese spare part can be considered justified. Secondly, at the end of the original cable there is a plastic angle (at 90 degrees), while the replacement has only direct soldering.
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For this reason, the cable must be bent at a right angle by hand to fit correctly into the socket. The manufacturer specifically makes it longer than the original and gives recommendations on the correct bend. This action shortens the service life of the part; in some cases, the contacts are unsoldered during installation. The question of whether to replace a damaged cable with a cheap Chinese product is something everyone decides on their own.
Nuances and conclusion
In general, there are not so many of them, cars are different, so the system for installing cushions and attaching the dashboard panel can be different. Otherwise, the essence is approximately the same for all. For example, in the 2nd generation Ford Focus you do not need to disconnect the battery, because you can remove the required fuse from the mounting block and wait 15 minutes.
If everything went well, then your task is to reinstall the dashboard panel and put everything else back to its original state. Replacing it yourself can save you a significant amount of money and time. There is nothing complicated about it except fiddling with the on-board computer.
Removing the part
Before you start dismantling any machine, you first need to prepare it a little:
- Align the steering wheel so that the car moves straight;
- Remove the key from the ignition switch and lock the steering wheel;
- Deactivate the negative terminal on the battery.
That's it, all that remains is to wait two or three minutes. The pause is needed so that the capacitor in the control system is completely discharged. The electrical circuit must be de-energized, avoiding short circuits.
What you need
Set of torx keys for cars Some tools will be needed, in particular, keys, screwdrivers. Their specific models depend on what exactly you plan to work with. Different brands of cars require different types of keys.
Step-by-step instruction
Before removing the airbag, it is worth understanding what version of it we are talking about and what model of car you plan to perform the task with.
Remove the airbag from the steering wheel
Let's consider the situation using the example of the Lada Priora car; in other models there may be minor differences (some examples are given below in the corresponding section), but the general essence is the same. Having carried out the preliminary preparation described above, we proceed as follows:
Turn the ignition key to the right. It is necessary that the lock opens so that the steering wheel can turn freely left and right. You cannot remove the key from the ignition, otherwise the steering wheel will lock; On the Priora-4, the steering wheel is spoked, and to remove the cushion, you need to tighten two countersunk bolts on the sides. A T27 sprocket key is suitable for this. With the steering wheel straight, first tighten the bolt on the left side
We turn the rotor 180 degrees and unscrew the other bolt. When both bolts are unscrewed, you need to pull the pillow towards you. It is important to be careful if the bolts are too tight - damage to the plugs is possible.
- Moving the pillow aside, holding the airbag with one hand, separate the plug from the middle of the device. You must first unclick the latch upwards, then remove the connector from bottom to top from the base;
- Now the signal wire is removed;
- You can remove the steering wheel itself, but do not forget to put the wheels straight before doing so so that the steering wheel is installed on the spokes in the same position;
- The steering column turn switch is being replaced, we are putting the parts back together.
Remove passenger
First you need to remove the glove compartment, then unscrew the existing protection in the same way with a Phillips screwdriver; when you see two bolts, unscrew them successfully, pry the plug off from above, and remove the wiring.
Remove other pillows
To remove the side airbag, you first need to disconnect the front seat assembly, the seat back. The safety fasteners are unscrewed. In principle, that’s all, you can remove it. And then screw it in and install everything back (if necessary, placing a new one in place of the old pillow).
New fastening nuts must be tightened correctly, it is important to correctly install the seat back upholstery, incorrect installation will interfere with the correct operation of the airbag. When laying the harnesses, you must ensure that they do not fray or get pinched by any foreign parts.
After installing the seat back, you need to check everything properly by moving it back and forth properly. The side airbag wiring harness must not be pinched during such actions.
Replacing knee airbags can be difficult because they come with latches and pins that are in an awkward location. A cardan wrench can get to them. Both nuts are removed, the cushion is removed, and reinstallation is performed.
In general, the pillows are changed according to the general principle - first, they are unscrewed, all latches, bolts, pins, nuts and other protective elements are separated, then everything is disassembled, the pillow is carefully removed, and you can put it back together.
