Low tire pressure light won't go out

recheck air level in all tires --if pressure good then tpi failure --when pressure is correct tri resets automatically

Are you sure it's not tpms this is the tire pressure monitoring system check the tire pressure if good it's just a sensor for tire pressure and should reset if pressure was low and you added air

That is the low tire pressure warning. It can come on for several reasons. It commonly comes on in the fall as temperatures drop, the air in the tires contracts and the pressure drops. Check the air pressure and fill as needed. The tires also all need to be within 4 psi of each other.
Another common cause is that one or more tire sensor needs the battery replaced. This is not generally considered a DYI project because for most cars the tires must be removed from the rims. Finally the sensor can be damaged by hitting a curb or by adding chemicals into the tire used to seal small leaks.
As long as you check your tires visually prior to driving it is usually ok to wait to service the sensor for when you replace or rotate your tires.

Please keep in mind driving on a tire with low pressure can damage the tire, the rim or even cause delamination of the tread and cause an accident. The Firestone recall that involved Ford Explorers several years ago was from driving on tires with low pressure.

Tire/s have low pressure and needs additional air added u ntil the proper tire pressure on all 4 tires are within operating limits. This will also extend the tire life. Tire pressure is printed on tire sidewall.

tire low on air pressure

TIRE PRESSURE MONITOR SYSTEM
The Tire Pressure Monitor System (TPMS) uses radio and sensor technology to check tire pressure levels. If your vehicle has this feature, sensors are mounted on each tire and wheel assembly, except the spare tire. The TPMS sensors monitor the air pressure in your vehicle's tires and transmit tire pressure readings to a receiver located in the vehicle.

The TPMS is designed to alert the driver, if a low tire pressure condition exists. This system also allows the driver to check tire pressure levels using the Driver Information Center (DIC).

When a low tire pressure condition is detected, the TPMS displays the "CHECK TIRE PRESSURE" warning message on the DIC, and at the same time illuminates the low tire pressure warning symbol.

You may notice, during cooler weather conditions, that the tire pressure monitor light, located on the instrument panel cluster, and the "CHECK TIRE PRESSURE" message will appear when the vehicle is first started and then turn off as you start to drive the vehicle. This could be an early indicator that the tire pressures are getting low and need to be inflated to the proper pressure.

Each tire, including the spare (if provided), should be checked monthly when cold and inflated to the inflation pressure recommended by the vehicle manufacturer on the vehicle placard or tire inflation pressure label. (If your vehicle has tires of a different size than the size indicated on the vehicle placard or tire inflation pressure label, you should determine the proper inflation pressure for those tires.)

As an added safety feature, your vehicle has been equipped with a tire pressure monitoring system (TPMS) that illuminates a low tire pressure telltale when one or more of your tires is significantly under-inflated.

Accordingly, when the low tire pressure telltale illuminates, you should stop and check your tires as soon as possible, and inflate them to the proper pressure. Driving on a significantly under-inflated tire causes the tire to overheat and can lead to tire failure. Under-inflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability.

Please note that the TPMS is not a substitute for proper tire maintenance, and it is the driver's responsibility to maintain correct tire pressure, even if under-inflation has not reached the level to trigger illumination of the TPMS low tire pressure telltale.

The "CHECK TIRE PRESSURE" warning message and low tire pressure light (telltale) will appear at each ignition cycle until the tires are inflated to the correct inflation pressure.

The Tire and Loading Information label (tire information placard) shows the size of your vehicle's original tires and the correct inflation pressure for your vehicle's tires when they are cold.

Your vehicle's TPMS can alert you about a low tire pressure condition but it does not replace normal tire maintenance.

NOTICE: Do not use a tire sealant if your vehicle has Tire Pressure Monitors. The liquid sealant can damage the tire pressure monitor sensors.

RESETTING THE TPMS IDENTIFICATION CODES
Each TPMS sensor has a unique identification code. Any time you rotate your vehicle's tires or replace one or more of the TPMS sensors, the identification codes will need to be matched to the new tire/wheel position. Each tire/wheel position is matched to a sensor, by increasing or decreasing the tire's air pressure. The sensors are matched to the tire/wheel positions in the following order: LF TIRE (left front tire on the driver's side of the vehicle), RF TIRE (right front tire on the passengers side of the vehicle), RR TIRE (right rear tire on the passengers side of the vehicle), and LR TIRE (left rear tire on the driver's side of the vehicle).

You will have one minute to match the first tire/wheel position, and five minutes overall to match all four tire/wheel positions. If it takes longer than one minute, to match the first tire and wheel, or more than five minutes to match all four tire and wheel positions the matching process stops and you will need to start over.

The TPMS sensor matching process is outlined below:

1. Set the parking brake.
2. Turn the ignition switch to "RUN" with the engine off.
3. Turn the headlamp switch from "OFF" to the parking lamps setting four times within three seconds. A double horn chirp will sound and the TPMS low tire warning light will begin to flash. The double horn chirp and flashing TPMS warning light indicate that the TPMS matching process has started. The TPMS warning light should continue flashing throughout the matching procedure. The "SERVICE TIRE MONITOR" message will be displayed on the Driver Information Center (DIC).
4. Start with the driver's side front tire.
5. Remove the valve cap from the valve cap stem. Activate the TPMS sensor by increasing or decreasing the tire's air pressure for 10 seconds, then stop and listen for a single horn chirp. The single horn chirp should sound within 15 seconds, confirming that the sensor identification code has been matched to this tire and wheel position. If you do not hear the confirming single horn chirp, you will need to start over with Step 1. To let air-pressure out of a tire you can use the pointed end of the valve cap, a pencil-style air pressure gage or a key.
6. Proceed to the passenger's side front tire, and repeat the procedure in Step 5.
7. Proceed to the passenger's side rear tire, and repeat the procedure in Step 5.
8. Proceed to the driver's side rear tire, and repeat the procedure in Step 5.
9. After hearing the confirming horn chirp for the left rear tire, check to see if the TPMS warning light is still flashing. If it is, turn the ignition switch to LOCK to exit the sensor matching process. If the TPMS warning light is not flashing, the five minute time limit has passed and you will need to start the process over beginning with Step 1.
10. Set all four tires to the recommended air pressure level as indicated on the Tire and Loading Information label.
11. Put the valve caps back on the valve stems. The spare tire does not have a TPMS sensor. If you replace one of the road tires with the spare, the "CHECK TIRE PRESSURE" message will be displayed on the DIC screen. This message should go off once you re-install the road tire containing the TPMS sensor. The "SERVICE TIRE MONITOR" message is displayed when the TPMS is malfunctioning. One or more missing or inoperable TPMS sensors will cause the service tire monitor message to be displayed.

Hello. Welcome to FixYa. Please allow us to assist you.

The ( ! ) symbol is the Low TIre Pressure Warning light. This light comes on when the a tire (or combination of tires) has insufficient inflation pressure.

When the ( ! ) light comes on, you need to get all of the tire inflations checked, and air added if the pressures are low. The proper pressure for your vehicle are on a sticker inside the metal pillar that is on the driver's side front door area.

Thanks for choosing FixYa for assistance today.

You may be low on air check all tires first then reset light. If it comes on again it is worth it to take it to the dealer

Some cars with tire pressure sensors also sense the pressure in the spare. Have you checked the spare?

Veve713:
You probably didn't need new tires unless you had some miles on it. Remember that the spare tire also has a pressure monitor as well. It most likely is causing the low tire pressure light on the dash and only needs to be inflated back to what ever your other tires are set to. I had the same problem on my RX and took it back to the dealership where they told me since the spare is exposed to the same elements (it's under the back of the RX - you have to use the tire iron to let the spare down), it will inevidably lose air.

Good luck.

MDGolfHacker