Every driver at least once faced with a situation when the dashboard lights up an incomprehensible symbol, causing alarm. One of the most common but often ignored signs is the image of a tire with the letter "S" inside a yellow triangle. This indicator is directly related to the tire pressure monitoring system (TPMS) or simply indicates the need to check the condition of the wheels. Ignoring this signal can lead to serious consequences, including increased wear of rubber, increased fuel consumption and even an emergency situation on the road.
In modern vehicles, such as Toyota Camry, Hyundai Solaris or Kia RioElectronics carefully monitors every parameter of the machine. If you see that the "S" in the triangle is burning, it means that the system has recorded a deviation from the norm. Most often, we are talking about a drop in pressure in one or more wheels below the permissible threshold. However, there are other reasons that you need to know about, so as not to spend extra money on diagnostics in the service.
Understanding what this signal means is a basic skill for any motorist. It is not just a light bulb, but a direct way of communication between the onboard computer and the driver. Mindfulness This prevents expensive suspension repairs or buying a new rubber kit ahead of time. In this article, we will discuss in detail all aspects of the indicator and the algorithms of actions.
The main value of the indicator and types of control systems
The symbol "S" in the triangle, which is often called the "tyre pictogram", serves as a universal warning. In most cases, it lights up in yellow or orange, which signals the need for intervention, but does not require immediate engine stop, as would be the case with a red indicator. The main purpose of this sign is to inform the driver of the low-pressure. The TPMS (Tire Pressure Monitoring System) system continuously reads data from sensors installed inside wheels or analyzes the speed of rotation of wheels through ABS.
There are two main types of systems that use this indicator. The first type is a direct control system, where a physical pressure sensor is installed in each wheel. Such systems are more accurate and show the pressure in each wheel separately on the display of the onboard computer. The second type is an indirect system that operates through ABS sensors. It does not measure pressure directly, but calculates it by the difference in diameters of the wheels: the flat wheel has a smaller radius and therefore rotates faster. That is why after pumping wheels in such systems is often required. manual settings.
It is important to understand that the indicator can burn constantly or flash. If the "S" in the triangle caught fire and burns smoothly, this usually indicates a static low pressure. If the indicator flashes within a minute after the ignition is turned on, and then burns constantly, this often indicates a malfunction of the TPMS system itself, for example, about the discharge of the battery in the sensor or a communication break with the control unit.
⚠️ Warning: If the indicator flashes when the engine starts, it could mean a failure of the pressure sensors, not just a flat tire. In this case, a simple tire swap will not extinguish the light bulb.
Causes of low pressure indicator lighting
The appearance of a warning sign on the dashboard always has a specific physical reason. The most common and common of these is the natural air leakage. The rubber wheel is not a completely sealed structure at the molecular level, and the air slowly leaves the tire during operation. In addition, the changes in ambient temperatures directly affect the pressure: when it cools, it falls, which is especially important in the autumn-winter period. If you have not pumped the wheels for several months, the probability of the indicator catching fire at the first cold is extremely high.
The second group of causes is associated with mechanical damage. Puncture of a nail, screw or sharp stone on the road leads to rapid air etching. Also, the cause may be a loose fit of the tire to the disc or a faulty spool in the nipple. Sometimes the driver himself becomes the culprit of the problem, forgetting to close the cap or not twisting it, which leads to a slow leak. In rare cases, the problem lies in the malfunctioning of electronics after replacing the car battery or carrying out repair work in the field of wheel arches.
Separately, it is worth mentioning the seasonal change of rubber. If you have installed wheels without pressure sensors (for example, old wheels or new rubber rearranged without rearranging the sensors), the system will fix their absence and give an error. An error may also occur if the sensors have not been “re-registered” after re-wheeling. In premium cars, such as BMW or Mercedes-BenzThe system may require calibration even after a slight change in pressure.
- 🌡️ A sharp decrease in the temperature of the air outside, causing compression of air inside the tire.
- 📌 Mechanical puncture or cut of the sidewall of the wheel by a foreign object.
- 🔋 The battery of the TPMS sensor (life is usually 5-7 years).
- 🛠️ No calibration of the system after wheel replacement or tire pumping.
The dangers of operating a car with a burning indicator
Many drivers perceive the burning yellow indicator as a minor detail that can be ignored until the nearest convenient occasion. However, operating a low-pressure car in tires carries real safety risks. With insufficient pressure, the area of the tyre contact spot with the road increases unevenly, which leads to overheating of the sidewalls. As a result, the rubber structure collapses, which can cause the wheel to explode suddenly at high speed, especially in the summer heat or on a long trip along the track.
In addition to the risk of rupture, low pressure negatively affects the handling of the car. The car becomes more "rolling", the braking distance increases, and the behavior in corners becomes unpredictable. The ESP and anti-lock braking system (ABS) may not work properly because they get incorrect data about the speed of rotation of the wheels. This is especially dangerous in emergency situations when the count goes on for a split second. Traffic safety It depends on the condition of the tires, and ignoring the signals of the control system can be too expensive.
The financial aspect cannot be discounted either. Under-inflated tire wears much faster, and unevenly: more ished edges of the tread. This leads to the need to purchase a new set of rubber much earlier than planned. In addition, the rolling resistance increases, which leads to increased fuel consumption. On a year-wide scale, saving time on pressure checks results in significant overpayments at the gas station and in the tire store.
Algorithm of actions during signal lighting
If the dashboard lit up "S" in a triangle, do not panic, but you can not postpone the solution of the problem. The first step is to visually inspect all four wheels for obvious damage or critical pressure reduction. If one of the wheels appears to be flat, stop in a safe place and either replace it with a spare one or call for help. If visually all the wheels look normal, you need to drive to the nearest gas station or tire assembly to measure pressure with a pressure gauge.
After measuring the pressure and bringing it back to normal (usually the values are indicated on the sticker in the driver's door opening or on the gas tank hatch), the error reset procedure must be performed. In most modern cars, such as Renault Duster, Volkswagen Polo or Lada VestaThis is done through the menu of the onboard computer. Find the option “Tyre Pressure” or “TPMS” and select the option “Install” or “Calibrate”. The system will then begin a new monitoring cycle.
☑️ Actions when lighting up the indicator
After resetting the settings, you need to drive a certain distance (usually from 10 to 30 kilometers) with a speed above 40 km / h. Only after this cycle does the system read new data and, if the pressure is normal, the indicator will go out. If after all the procedures the light bulb lit again, then the problem is not temporary, but permanent, and requires diagnosis by specialists.
⚠️ Note: Do not ignore the indicator re-ignition immediately after resetting. This is a sure sign that there is an air leak in the wheel that needs to be fixed.
Seasonal features and change of rubber
The change of season is the most common trigger for the appearance of pressure error in tires. When you switch from summer rubber to winter rubber or vice versa, the physical properties of air change. As the law of physics says, when the temperature drops every 10 degrees Celsius, the pressure in the tires drops by about 0.1 atmospheres. Therefore, if you install the wheels after summer storage, you are likely to see a burning indicator, even if the pressure was ideal in the summer.
In addition, with seasonal replacement of rubbers, the wheels in the assembly often change. If you use a set of drives without TPMS sensors (relevant to indirect systems or systems where sensors have not been rearranged), the car may not “understand” that the wheels are replaced. In some cases, for example, in cars. Nissan or MitsubishiIt requires a mandatory procedure for training the system to new parameters through a diagnostic scanner or a special sequence of actions with buttons.
In winter, it is also worth considering that in the cold, rubber blubbers, and micropunctures, imperceptible in the summer, can cause a faster loss of pressure. It is recommended to check the pressure in winter more often than in summer, preferably once every two weeks or before each long trip. Use of the nitrogen instead of air In tires, the pressure can be slightly stabilized, since nitrogen is less susceptible to temperature expansions, but this does not eliminate the need for regular monitoring.
Effects of Temperature on Pressure
When the tire is heated in motion, the pressure inside it increases. Therefore, manufacturers recommend checking and adjusting the pressure only in the “cold” tires, when the car stood for several hours. If you pump the hot wheel to normal, then after cooling the pressure will fall below the permissible, and the indicator will light up again.
Diagnostics of TPMS system malfunctions
There are situations when the pressure is normal, the wheels are intact, but the indicator continues to burn or blink. This indicates a malfunction of the monitoring system itself. The first suspect is usually a pressure sensor. Inside each sensor is a lithium battery, the life of which is limited. It is not replaced separately, so when it is discharged, you have to change the sensor entirely. The service life of such batteries is on average 5-7 years, which coincides with the life of a good set of rubber.
Another reason may be mechanical damage to the sensor. With careless tire fitting, when the wizard uses the wrong tool to remove the tire from the disk, you can easily damage the sensor leg or its body. Problems can also arise with the antenna reception in the cabin of the car, especially if work was carried out on the cabin tightening or installation of additional equipment that creates radio interference.
Accurate diagnosis often requires the use of a specialized scanner that can read the ID code of each sensor and check its charge. At home, you can try the exclusion method: if after a reset and a long trip, the indicator lights up again, try to visually assess whether a wheel has lowered more than others during the night. If all the wheels keep the pressure, and there is an error - the way is only to the service.
| Symptoms. | Probable cause | Action required |
|---|---|---|
| It's burning all the time. | Low pressure in one or more wheels | Check the pressure with a pressure gauge and pump |
| Blinks for 1 minute, then burns | TPMS system malfunction or sensor discharge | Scanner diagnostics, sensor replacement |
| It only lights up in the cold. | Temperature compression of air | Reduce the wheels to normal, taking into account the temperature |
| Light up after wheel replacement | Lack of calibration or sensors | Perform reset and calibration through the menu |
| Burning after pumping | Failure to reset error | Find the “Pressure Set” menu and confirm |
Tips for Tire and Sensor Care
To minimize the risk of unpleasant surprises on the dashboard, you should adhere to a few simple maintenance rules. First, always use caps on nipples. They not only protect against dirt and moisture, but also provide additional tightness. Second, with each seasonal tire replacement, ask the TPMS sensors to check the condition and replace the O-rings with them if necessary.
If you plan a long parking lot (more than a month), it is recommended to increase the pressure in the tires by 0.2-0.3 atmosphere above normal. This compensates for the natural leakage and will prevent the appearance of flat tire deformation. Before the start of operation, the pressure will need to be returned to normal values. It is also useful to have a compact electronic pressure gauge in the glove compartment, since the readings on the refueling columns are often inaccurate.
Buying a new set of winter or summer rubber, immediately purchase new caps on nipples with sealing pads. Old, shrivelled caps can cause a slow leakage of air, which is difficult to notice visually.
Remember that your blood pressure control system is your assistant, not your enemy. It is designed to protect your money and your life. Regular maintenance of the wheels and timely response to the dashboard signals will allow you to avoid emergency situations on the road and extend the life of expensive components of the car.
Regular pressure check (every 2 weeks) and visual inspection of the wheels can prevent 90% of problems associated with sunbathing of the indicator "Sh".
Frequently Asked Questions (FAQ)
Can I drive if the "S" is burning in a triangle?
You can drive, but carefully and not for long. The indicator warns of low pressure, which worsens handling and increases the braking distance. It is necessary to find a place for tyres to be pumped as soon as possible. If the indicator flashes, operation of the car is not recommended before diagnosis.
Why does the indicator burn after the wheels are pumped?
You probably didn’t perform the error reset (calibration) procedure through the onboard computer menu. The system remembers the previous low pressure and requires confirmation that the normal has been restored. It is also possible that there was a puncture in one of the wheels.
How much does it cost to replace the tire pressure sensor?
The cost of the sensor varies from 1500 to 5000 rubles depending on the brand of the car and the manufacturer of the sensor. Plus, you need to add the cost of work on disassembling the wheel and programming a new sensor in the service.
Does the type of rubber (spikes/Velcro) affect the indicator?
The type of tread itself does not affect. However, if you change the tires and do not “prescribe” new sensors (or not), the system will give an error. Also, winter tires are more sensitive to temperature changes, which often causes the system to work.
How do I know which wheel has the pressure dropped?
In vehicles with advanced TPMS, information is displayed on the on-board computer screen as a car diagram with pressure numbers for each wheel. If you have a basic system, you will have to check all four wheels with a manometer manually.