What is a tire pressure sensor?

A tire pressure sensor (TPS) is an electronic device fitted to the wheel of a vehicle. The function of the TPS is to measure and feed information to your car’s ECU about the air pressure inside the tires. These sensors sense pressure as it varies with temperature, making them susceptible to variation in ambient conditions such as humidity and heat. They are usually made of a metal wire that is coiled up in a canister. Inside the canister, wire is a disc with mercury (Hg) coating on one side and vanadium oxide (VO2) coating on the other. When pressurized air gets into the sensor, it moves the disc to separate contacts between the two. This sends a signal to the ECU based on whether the mercury or vanadium oxide contacts have been triggered by pressure, thus determining what the tire’s air pressure is.

How do tire pressure sensors work?

A malfunctioning TPS can cause your car not to start or even damage your fuel system. This is because the ECU cannot determine the correct tire pressure based on the incorrect data it gets from your TPS. It will either shut down or run with incorrect air pressure, resulting in fuel economy loss and overheating.

The most common causes of TPS failure are below:

1) Tire damage – A tire can be easily punctured by debris on the road or wear and tear that comes with regular use. If you suddenly feel like your car is pulling to one side, it could be because you have a punctured tire. In this case, you should immediately replace your damaged tire to avoid further damage and danger.

2) Voltage spike – A voltage spike happens when the TPS is connected to a voltage supply higher than it was designed for. This can be caused by a car battery that has been left on charge overnight or faulty wiring. It can also be caused by electric shorts, switchers, and electrical storms. This is dangerous because it can cause an explosion or ignition through your TPS contacts. If the voltage spike happens frequently, it might damage your engine components due to excessive heat generated during fuel/air mixture (which won’t be optimum).

3) Physical shock – A TPS should be protected from physical shocks as much as possible, but sometimes surprises happen. If your air pressure is incorrect and you run over a pothole or a sharp object along the road, this can damage your TPS and cause it to stop functioning correctly.

4) Poor electrical connection – This is another common cause of TPS failure. Some vehicles have their battery located inside the trunk (for example, in some older Honda Accord models). This means that if your box or boot is not closed correctly or your car’s bodywork has rusted at any point, and metal has come into contact with wires, it can cause poor electrical connection.

5) ECU failure – If your ECU malfunctions, this can cause the TPS to malfunction too.

If you are having trouble with your car’s TPS, take it to a mechanic or an auto electrician to fix the problem for you. This is because it requires concrete tools and knowledge of electronic circuits to repair your TPS.

You can avoid these problems by continuously checking the air pressure in your tires before you drive and ensuring that your trunk or boot is closed correctly. If the problem persists, see a mechanic as soon as possible to prevent further damage to other components on your car.

-Tire pressure sensors are electronic devices fitted to the valve stem of a car’s tires. The TPS is used to measure and monitor tire pressure, giving data to the electronic control unit (ECU) about how much air pressure there is inside each tire. The ECU uses this information, and other signals such as throttle position and engine speed/load, to adjust torque, acceleration, and deceleration. If your car’s TPS malfunctions, you might end up driving with too much or too little air pressure in your tires, risking tire failure and causing damage to other components on your vehicle.

A TPS is composed of a small cylindrical metal canister (housing) with two electrical connectors at one end. Inside the canister are two small metal plates which rest against an air valve when they are not connected to the car’s electrical system. These metal plates are held apart by a flexible rubber ring. When connected to the car’s 14-volt battery, charge runs through the connector and into the TPS’ inner workings. This causes a license to build up between the metal plates. The electrical charge causes a small amount of current to flow between the two metal contacts inside the sensor housing, making them hot enough for the solder to melt and join them together. This creates an electrical path from one connection to another through the sensor’s rubber ring. In this way, as soon as the sensor is activated, the rubber ring is heated and begins to expand. This causes the electrical path between the contacts inside the canister to become more open, and as a result, tire pressure is measured and sent to the ECU.

The TPS should not be used on some higher-powered vehicle models because it can cause damage due to incorrect voltage requirements of the vehicle. Also, if you are using the TPS on an older vehicle model with its battery located inside the trunk or under the front seat of your car, it can cause poor electrical connection due to corroded wires/connections causing inconsistent voltage levels.

It would help if you also took extra care not to touch any of the wirings in your car’s engine bay or TPS with your hands because the natural oils and residues on human skin can cause corrosion, interfering with voltage measurements.

If you do not follow these guidelines and accidentally touch electrical wiring in the engine bay or TPS, then you could end up causing damage to other components of your vehicle. You might also cause a short circuit, which is dangerous because it keeps the car electrically alive even when it’s turned off.

Keep in mind that if you are having problems with your car’s TPS at any point, you should always take it to a mechanic or auto electrician for repair and replacement. For example, if the rubber ring has melted and broken, you should replace the entire TPS, not just the rubber ring. This is because if you try to repair the sensor yourself, you could use inferior materials that corrode quickly and faulty parts that cause other problems on your car.

How to fix the tire pressure sensor?

-Tire air pressure sensors are used to measure and monitor tire pressure, giving data to the electronic control unit (ECU) about how much air pressure there is inside each tire. Replacing your faulty TPS will require you to follow these steps:

-The first step is to find the location of your car’s TPMS unit. You can do this by looking under the driver’s side of your car’s dashboard and following the wiring from the back of the TPS unit to where it connects to your car’s wiring system.

-Next, use a wrench to unscrew and unclip any fasteners holding your car’s TPMS unit in place. Stick the tape onto anything you don’t want to be scratched by other components under your car’s hood before you unscrew anything.

-Support your car’s TPS unit with a jack so that it is not hanging from its wiring, causing undue pressure on the connector. Then, disconnect the wiring harness which attaches to the back of your car’s TPS unit by pushing in clips and pulling out connectors until everything has been disconnected.

-If your car’s TPMS unit is still working, you will need to switch it on so that you can see which tire(s) are low on pressure. Put the key into the ignition and turn it clockwise until all of the dashboard lights come on. Then move the key back towards yourself, stopping when you hear a clicking sound. This means that you have switched on your car’s TPMS.  

If the tires do not go into the red zone, then more tire valves need to be replaced. If that doesn’t solve the problem, check for any issues with sensor batteries and replace them if necessary.

-After replacing each tire pressure monitoring sensor valve, reset your TPMS by removing the key from the ignition and turning it back on again.

-The last step is to put everything back in its original position so that you can drive safely. Reinstall all of the screws, clips, and fasteners holding your car’s TPS unit in place.

How to reset the tire pressure sensor?

-You can reset the TPMS by waiting for six hours, after which it will automatically reset itself. If you wish to reset your car’s TPMS unit manually, turn the key clockwise until all of the dashboard lights come on, and then move it back towards yourself until you hear a clicking sound. Turn the key again, so it is not entirely on position, and then wait six hours. Once this time has passed, turn the key back into the entirely on assignment for a few seconds before turning it off again.

-Whenever you change a tire or fix a flat, make sure that you reset your car’s TPMS unit so that it can monitor each wheel properly. Make sure that you check the color of the light which appears on your dashboard when you start your car to make sure that all tires have been appropriately reset.

-You can also manually fix a TPMS sensor by removing it from its place, waiting for 20 minutes, and then putting it back in before driving the car again. This will reset the TPMS.

-The last possible way to reset the TPMS yourself is by using a flat, flexible tool like an unbent paper clip or guitar pick and pushing it into the small circular button on your tire’s tread, which resets most TPMS sensors. This will require you to use some force, but if done correctly, it will allow you to reset the TPMS so that you can continue driving.

-If none of these methods work, your car’s TPMS unit may have to be replaced. This will require you to take your vehicle to a professional who can diagnose and replace or fix it for you.

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