Often, car owners have a situation where the rear brake lights do not light up. An experienced motorist can guess what the reason might be. Therefore, it will not be difficult for him to determine the source of the malfunction and eliminate the problem. For beginners and inexperienced owners, it is advisable to contact specialists or study reliable information on car repairs.
This article outlines the main causes of this malfunction and provides recommendations for eliminating it. The owner of the car can make the repairs himself or contact a car service center.
Causes of malfunction
The main reasons for this malfunction are:
- defective or burnt out light bulb;
- break in electrical wiring or plug connections;
- fuse blown due to a short circuit or overload in the on-board network;
- limit switch malfunction;
- problems with electronic systems or units.
Such malfunctions can usually occur on high-mileage vehicles. However, there are exceptions.
Broken brake pedal sensor
One of the possible factors for error P0504 to appear in a car is a breakdown or defect of the pedal end switch itself. It is worth noting that the quality of AvtoVAZ consumables has always suffered, and this is the case now. Even Russian sensors are mostly equipped with fairly cheap springs and contacts made in China. The result is that the springs fail and the contacts usually burn out after 5-8 thousand miles.
Due to the spring, the regulator rod does not return to its original position, therefore, the system receives a notification that the brake pedal is pressed. In this situation, the ECU reads that both the brake and gas pedals are pressed together. Therefore, the throttle valve is forced to close.
In many cases, replacing the pedal adjuster on the Grant solves the problem associated with fault 0504. However, it happens that a working sensor refuses to work after installation, and then it is necessary to consider other possible causes.
Brake lights don't come on completely
If the brake lights on the car stop lighting completely, then you should look for a break in the wires, in the limit switch or a faulty fuse. The search for a breakdown should begin with the fuse box. On its cover there is usually a table showing which circuit is protected by which fuse link. If it is missing or the information in it is unreadable, you can use the owner's manual for the vehicle.
If the required fuse has blown, it cannot be replaced until the cause is determined. This usually happens when there is a short circuit or the insulation of the wires is damaged and they touch the housing. A similar effect is observed when water gets into electrical connections. In this case, it is necessary to dry the area where moisture has entered. To speed up the process, you can use a hair dryer (being careful not to melt the wire insulation or sheathing elements). Then you need to remove the fuse from the holder and test the circuit after it with a multimeter.
Often the wires fray at the point where they pass from the body to the trunk lid. Typically, the casing must be removed to detect cable damage. Therefore, in the absence of proper experience, it is better to entrust this work to a service center. If damage is found, the insulation coating must be restored. To do this, you can use ordinary insulating tape.
If the fuse is OK, you can assume the limit switch is faulty. It is located in the pedal assembly. It is necessary to inspect the condition of the switch and test it with a multimeter while the brake pedal is pressed. The multimeter should show a resistance of less than 1 ohm. If it is large or the switch has mechanical damage, it must be replaced. Due to the complexity of such an operation, it is better to entrust it to experienced car service workers.
If both the fuse and the limit switch are not damaged, this indicates a broken wire. To find such a fault, you will also need to open the casing. If you lack experience, it is better to entrust these actions to a car service.
If a wire break is detected, it is necessary to strip the insulating layer from the wire, make a connection and insulate the joint. A break in a section of wire is repaired by soldering. To insulate the connection, you can put on heat shrink tubing and heat it until it is fixed to the wire. If the terminal breaks, it is removed from the plastic case and replaced with a new one, crimping the stripped end of the wire into it, then inserted back.
How to replace lighting
When replacing light bulbs, Granta holders give preference to products from Osram or Philips due to the good price-quality ratio and high luminosity. No special tools are required for replacement.
The car enthusiast will only need gloves, as well as napkins and alcohol (if gloves are not on hand). Replacing lamps does not involve dismantling components - you just need to remove the terminal from the battery.
Gloves or wipes soaked in alcohol are required to avoid accidentally contaminating the bulb of the new lamp during installation by touching it with dirty hands. The algorithm of actions when changing the lighting source is as follows:
- The plastic cover behind the headlights needs to be removed. To do this, press on the tab and then carefully remove it without damaging the guides.
- Pull out the plastic headlight cover.
- Pull the block on which the electrical wiring is located from the lamp output. You should be able to remove the terminal without effort.
- Remove the rubber seal. Remove the rubber seal as shown in the figure
- Press the spring clamp antennae on both sides, moving them away from the reflective hooks in the headlight.
- Take out the light bulb from the Lada Granta.
- Install the new device, holding it by the iron part, back into the Lada headlight.
Remember, if one lamp burns out, you will still have to change two. This is due to the difference in light flux even between products from the same manufacturer.
Lada Granta Liftback - introduce the Granta model family that came off the assembly line in May 2014. The car is offered with three different engines and in three trim levels: Standard, Normal and Luxury. The cost of a car starts from 330,000 and up to 500,000 rubles.
In this article we will describe in detail the process of replacing lamps in the rear lights on a Lada Granta liftback yourself, without the help of an auto electrician or a car service center.
Separate brake light does not light up
If only one brake light does not light, then the most likely problem is the lamp or poor contact in the socket. In this case, you need to disassemble the trunk trim on the side of the car where the signal is not lit. If necessary, remove the lamp unit, remove them from the sockets or holders, carefully inspect the contacts in the socket and on the lamp base.
The presence of rust, traces of oxidation (white or greenish coating), soot, as well as dust or moisture confirms that the brake light does not light due to missing or poor contact in the circuit. Cleaning the indicated areas will help eliminate the problem. To remove rust and oxides, you will need a sharp object, such as a screwdriver. It is also necessary to check the serviceability of the lamp. To do this, you can use a multimeter or the on-board voltage supplied to the lamp via wires through a fuse. The burnt-out lamp is replaced with a similar new one.
Search principle
To find a fault in any vehicle on-board network system, you should use the method of sequential elimination of elements. The point is to consistently check electrical appliances and sections of the circuit, excluding elements from the list of reasons that could cause a breakdown. To do this, you need to clearly understand the design and operating principle of the system. When troubleshooting, you need to move from the components that require the least effort to check, to the most difficult to diagnose elements.
Electrical diagram
We immediately emphasize that the pinout of connectors and color markings of wires may differ not only between different models of the same automaker, but also among one model of different years of manufacture. Before you start searching for the cause of the breakdown, you need to find an electrical diagram specifically for your car model.
The additional brake light does not light up
If the additional brake light does not light up, this indicates a break in its wires or an unreliable connection. It usually connects to one of the stock brake light sockets. It is necessary to ensure that the wires are securely fastened and that there are no signs of oxidation.
If they are present, it is necessary to cut off the damaged end of the wire, clean it again and connect it to the socket. If the cable is broken in another place, it is advisable to install a new one. In this case, it is better to use a thicker wire (to avoid recurrence of the malfunction).
How to properly replace a burnt out element
Removing the fuse box
You need to pull the fuses out of the corresponding sockets using special plastic tweezers, which can be found here, in the upper right corner of the VAZ 2114 mounting block. You cannot pry fuses on non-energized circuits with any metal objects due to the risk of a short circuit. It should be taken into account that the electrical circuits of the sound signal, alarm, etc. are always energized. To ensure safety when repairing the circuits, the circuit must be de-energized - you just need to disconnect the wire from the “negative” terminal.
It is not always possible to visually accurately determine the performance of fuses. It will be possible to make a clear decision only after the “ringing”. To do this, you will need a regular tester, which will need to be set in advance to the “dialing” mode. After this, it will be enough to simply attach two terminals of the tester to the terminals of the suspicious fuses. If a characteristic sound is heard, the fuse is good - the cause of the malfunction of the car’s equipment is not in it, but probably somewhere further in the wiring or in the device itself.
Lastly, never use copper “inserts” or fuses that are not rated for amperage. Using an inadequate replacement designed for a higher current, there is a risk of damage to the “track” of the unit’s printed circuit board and even failure of the electrical appliance. Insufficiently powerful fuses will not be able to ensure long-term and uninterrupted operation of the current consumer in the vehicle's electrical network.
Malfunction of LED brake lights
If, after carrying out the measures described above, it is not possible to determine the reason why the brake lights do not light, you should clarify the type of lamps used. They can be made using LEDs. Their installation has a number of features. Typically, LED lamps have a certain polarity for connecting to the vehicle’s on-board network.
Manufacturers always take this into account when developing. Incorrect connection results in the lamp not lighting up. In some cases, such inclusion may lead to damage. If a connection polarity violation is detected, this indicates that the repair on the vehicle was carried out by an unqualified person.
Carrying out pre-installation diagnostics
Before purchasing and installing a new sensor to replace a broken one, it is recommended to diagnose the old sensor and, if there is a breakdown, fix it yourself. There are two nuts on the sensor body, the first of which is located at the bottom, and the second at the top. The nut located at the top should adjust the clearance of the part (sometimes it is set incorrectly). This leads to disruption of the normal functioning of the button, therefore, you will need to set the gap so that there are no obstacles to its normal movement.
After the adjustment, the ECU error is reset, then you need to start the engine and wait about fifteen minutes, since errors are not recorded immediately. If error 0504 is not marked, it means that the cause of the engine malfunction was an incorrect sensor setting. If it appears again, you will need to replace this element with a new one.
Car alternator malfunction
LED lamps are very sensitive to voltage surges in the on-board network (along with this, the current through the LEDs increases, which leads to their destruction). The voltage may increase if the generator components (namely the stabilizer) are faulty. This is especially common on domestic cars due to the lower quality of component production compared to more well-known brands.
Therefore, if the brake light on a VAZ 2114 or another model does not light up (provided that LED lamps are used), you should also check the generator and replace the damaged element, then change the lamp.
Such a malfunction can occur periodically and is associated with wear and tear of the entire generator. If the brake lights on the VAZ 2115 do not light up and other breakdowns often occur, you should also think about replacing it with a more reliable car (in some cases, this is more profitable than constantly investing money in endless repairs).
Auto-assistance
In the diagram we presented, the elements are depicted as close as possible to how they look in reality. Don’t be alarmed if you only find a schematic diagram for your car with symbolic images of the elements. Schematic diagram of external lighting for VAZ 2114, 2115:
- 3 – mounting block;
- 8 – lamps for side lights and brake lights;
- 11 – brake light limit switch;
- K4 – relay for monitoring the serviceability of brake light lamps and side lights.
Fault localization Understanding the operating principle allows you to determine exactly why the brake lights may not light up:
Malfunction of brake lights together with other indicators
Quite often, the brake indicator lamp is used together with the side lighting of the car. One cylinder contains two filaments, one end of which is connected to the base, and the other two are brought out to separate contacts. If the brake lights and parking lights do not light up, the most likely loss of contact is at the point of their connection to the body (“ground”) of the car or in the socket. This can happen due to a broken wire or oxidation. The broken end is connected to the terminal by soldering or crimping. Oxides are cleaned off with a sharp tool (knife or screwdriver); after repair, it is advisable to cover the joint with paint or grease to prevent re-oxidation.
It is quite rare to encounter a malfunction when not only the brake light, but also the other indicators on the car do not light up. This is usually observed in “drowned” cars that have somehow been in water (as a result of careless driving or an accident). Even after thorough drying, moisture still remains inside the interior trim and electronic components. Its presence leads to increased oxidation of conductive surfaces. In such a car, having eliminated the malfunction of one system, you cannot be sure that it will not appear again.
Power fuses Lada Kalina
The main power fuses and the diagnostic connector are located under the cover next to the cigarette lighter.
You can also read about Lada Granta fuses, if you have such a model in your fleet.
I hope this article will help solve your electrical problem. Just in case, take with you spare fuses and, if possible, relays, then you won’t need to look for them at the most inopportune moment or after hours in car dealerships.
Other causes of brake light failure
Sometimes the reason why the brake light on a car does not light up is a malfunction of the electronics. In this case, it is better to take the car to a service station.
There are also exceptions, for example, when a defective light bulb comes across. In addition, lamps may burn out due to normal wear and tear. In these cases, the problem is solved by simply replacing them.
Do not forget that you need to contact only trusted workshops. Often, the intervention of unskilled workers leads to additional malfunctions.
Prices and options
| Execution option | Engine | Equipment | Plastic bag | Transmission | Model | Price, rub.) |
| A0 Standard | 1.6 l 8 class, 64 kW (87 hp) | 001 | MT | 21901 | 519 900 504 900 | |
| A1 Classic | 501 | MT | 21901 | 550 500 535 500 | ||
| 538 | Optima | M.T. | 576 500 561 500 | |||
| A1 Comfort | 1.6 l 8 class, 64 kW (87 hp) | 543 | MT | 21901 | 598 500 583 500 | |
| 1.6 l 16 cl., 72 kW (98 hp) | 501 | AT | 21902 | 683 500 668 500 | ||
| 1.6 l 16 cl., 78 kW (106 hp) | 544 | MT | 21907 | 618 500 603 500 | ||
| A2 Luxe | 1.6 l 8 class, 64 kW (87 hp) | 501 | MT | 21901 | 637 800 622 800 | |
| 1.6 l 16 cl., 72 kW (98 hp) | 501 | AT | 21902 | 722 800 707 800 | ||
| 1.6 l 16 cl., 78 kW (106 hp) | 501 | MT | 21907 | 657 800 642 800 | ||
| 537 | Prestige | 676 800 661 800 | ||||
| #CLUB | 1.6 l 8-cl. (87 hp) | V04 | MT | 21901 | 615 900 | |
| 1.6 l 16-cl. (106 hp) | V02 | MT | 21907 | 635 900 |
Additional payment for metallic body painting is RUB 9,000.
* — Recommended retail prices taking into account the maximum benefit from current promotions
