Car tire warning light, if it comes on you will get in trouble: this is what it means

When and how to reset the TMPS sensor: find out what to do if the tire pressure light is on.

Car tire reset button
Car tire reset button –

A warning light may appear on the dashboard of the vehicle, the icon of which may resemble an exclamation mark floating in a swollen tire. The light is usually yellow and can be solid or flashing.

Typically, this light indicates a puncture or an air free tire. What it indicates is a malfunction rather than a real and concrete problem. It is therefore advisable to stop the vehicle as soon as possible and to check the condition of the tires as soon as possible.

Tire pressure warning light: what to do and why does it come on?

The tire pressure warning light comes on when a fault strictly related to the condition of the tires is detected. This means that as soon as it comes on, the car’s sensors send a low tire pressure signal to the ECU. It does not indicate a specific fault, so if you are driving, you must stop and check the situation.

The most common problems are related to tire pressure. However, sometimes it is not obvious that this is a simple pressure drop and there are several problems to be solved. Usually, if the light comes on constantly, it is certain that the pressure has dropped below the minimum parameter. On the other hand, if it turns on and off, it is a completely different anomaly. Often this is also a failure of the sensor used to detect the correct pressure level.

When the tire pressure light comes on, you immediately think about how to reset the TPMS sensor. Today we will talk about the circumstances under which the warning light comes on and the causes of the TPMS sensor failure, we will examine when it is necessary to reset the TPMS sensor and most common mistakes pressure monitoring system.

Tire pressure warning light –

Passive and active TPMS sensors

Since TPMS sensors are required for newly homologated vehicles (starting from 1 November 2014), there were several problems with the tire pressure warning lights.

Before we start talking about TPMS sensor reset, it is important to make a distinction between Passive TPMS (which uses an ABS sensor) e TPMS active (each wheel has its own dedicated sensor).

Active tire pressure sensors are undoubtedly more accurate, but more care must be taken to avoid the tire pressure warning light coming on. Today we will therefore focus on resetting the active TPMS sensor and what to do when the light comes on, as well as some common causes and solutions.

First, it is important to know that resetting the TPMS sensor is different from initializing.

TPMS initialization is usually done in the workshop to program a new TPMS sensor in the event of a tire or sensor repair or replacement. The reset of the TPMS sensor, on the other hand, concerns the reference air pressure and can also be done by yourself.

TPMS reset for flat tires or sensor damage

When the tire pressure light comes on, the most common mistake is to immediately imagine a puncture. In these cases, it is best to slow down, avoid abrupt maneuvers and stop in a safe place for check for a puncture or any other problem.

The TPMS warning light coming on as soon as the engine starts can be an indication that there is no problem with the tires. However, before resetting the sensors, you need to make sure there are no punctured or damaged tires.

Tires –

Check the tire pressure before resetting the TPMS

To ensure that the tires are checked, it is necessary to have a reliable pressure gauge (not always the one at the service station) and to check when the tires are cold.

In general, car manufacturers define “cold tires” in their user manuals as vehicles that are stationary in the shade or that have not traveled more than 1.6 km in three hours. The recommended tire pressure is usually indicated on a plate visible when the driver’s door is opened.

Note: If the tires show the correct value when the rubber is hot while driving, it clearly means that in cold weather they were deflated and the TPMS warning light has come on. It is advisable to let them cool and check them again.

When to reset the TPMS sensors

Surely when the tire pressure warning light comes on and does not go off. However, make sure the tires are properly inflated according to the recommendations above and are not damaged or punctured. It is strongly recommended to reset the TPMS only after having checked and ruled out the main causes of the fault.

You can always find out from the vehicle manual whether the TPMS light is on due to a puncture or a fault. Typically, if the tire is not punctured, the tire pressure warning light should automatically go out once the failure factor is no longer present.

The spy TPMS can light up:

– if there is snow on the wheels.
– if you are near a power station, an antenna or an electronic device near the wheels or in the car.
– if snow chains are fitted.
– if a metallized film or a blackout film containing metal particles is applied to the body (less and less common).
– if the punctured tire has been replaced with a spare tire which does not normally incorporate a TPMS sensor.

Flat tire –

How to reset TPMS sensors

Resetting the TPMS allows you to set a new reference pressure value which will be considered by the control unit as an alarm threshold. Resetting the TPMS sensor can take several minutes, so make sure you:

– be able to drive at a speed of at least 25 km / h
– do not go over 100 km / h
– be able to drive at least 10 minutes
– avoid bad roads.

There TPMS sensor reset procedure it is usually done by accessing the on-board computer menu. However, it is advisable to consult the car manual, as the time and speed to be respected vary depending on the type of vehicle.

If the tire pressure light stays on for several days, it is best to contact the workshop to confirm that the TPMS is defective.

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