While having an onboard computer in cars has considerably improved overall car safety, glitches can occur that become more of a hindrance than a help. If your tire pressure indicator has been blinking at you for days and you’re getting sick of it, a reset may be in order. In this article, we’ll be looking at methods on how to reset TPMS.
What is TPMS, and Why is it Blinking?
Tire Pressure Monitoring System or TPMS is an electronic gauge responsible for keeping track of changes to the pressure of a car’s tires. This system is meant to ensure that the air pressure in tires remains at a safe level. The warning light comes on when the pressure changes too drastically.
If the pressure drops too low, the tires will rotate faster and strain the car. Excess strain can result in skids and blow-outs.
How Does TPMS Work?
There are two different systems of tire-pressure monitoring used in Europe and North America.
European cars use what is called an indirect TPMS. It works through sensors located in the ABS or on the speed sensors of each wheel. Some vehicles use both.
Indirect TPMS measures changes to the wheels’ rotation speed. As stated earlier, the less inflated a tire is, the faster it turns.
North American cars most often use a direct TPMS. This type of system is found directly –as the name implies – on each tire’s rim or pressure value.
Direct TPMS can show false readings in bad weather or if they corrode over time. They also may put the tire out of balance.
How to Reset TPMS
Be 100% sure that the tires are correctly inflated before trying to reset the TPMS. There should be a label inside the driver’s door that dictates the appropriate tire pressure. Do not go by what the tire says as that is the maximum possible inflation; not the recommended.
To reset the TPMS, use a TPMS resetting tool. This tool uses the IDs of each tire’s sensor to reprogram them. The manner in which TPMS tools work can vary, so be sure to follow the instructions closely.
If, for some reason, this doesn’t work, or you are looking for a method that does not require a specialized tool, try the following option.
How to Reset TPMS: Take Two
It is becoming more and more common – at least for cars with direct TPMS – to have a dedicated reset button. The button’s location can vary by brand, but they are usually located under the steering wheel.
Turn the car on, only to the accessory level – don’t start the engine – and hold down the reset button for three seconds. Once the TPMS light starts blinking, turn on the ignition and go from a 20-25 minute drive. Following these steps should recalibrate the system.
If your car does not have a reset button, drive around at 50 miles per hour for about 10 miles or so. Keep the speed consistent. This method is best suited to indirect TPMS models but may work for direct systems, as well.
Still Didn’t Work?
Sometimes the issue isn’t with the TPMS at all, but rather it’s the computer itself. To reset the computer, you could disconnect the battery. However, it may be a better idea to take it to the service department at a Phoenix Ford dealership.
Make sure the car is off before tinkering with the battery. Disconnect the battery’s positive cable, and then hold the horn to drain any residual power. It should take about three-ten seconds.
Once the horn goes dead, reconnect the battery. The computer should have reset, and the light will be off.
Other Reasons TPMS May Glitch
If none of the above methods work, the sensors may be damaged. Unfavorable weather, regular mechanical services, or faulty parts could cause the sensors to break. Many sensors also have their own batteries. If the batteries are dead or dying, the readings may be skewed.
If this is the case, the sensors will have to be replaced. In some cases, if the sensor is built right into the wheel, it may be cheaper to buy a new wheel.
A Note on Resetting TPMS
Always let the tires cool first before trying to do anything with them. As you drive the car, the air inside the tire heats up and expands. This heat may skew the readings.
Additionally, only fill the tires when they are cool as well. Filling the tires with hot air will give a false pressure reading, and they will end up being underinflated.
While the little light may be annoying, it is always important to remember that it is there as a warning. Only try to reset it if you know the tire pressure is correct. If the above methods do not work or you are unsure what to do, it is always safest to take the car in for service.