Tpms
 

After running through the car wash and a few errands last night, I turned on my 2012 Elantra to find the "Low Tire Pressue" light blinking at me, then staying on after about a minute. I checked manually and found the tire pressure to be at (actually a little above) factory recommendations, and consistent in all 4 wheels.

When I got up this morning- no changes and the light is still on.

Any thoughts on what could have set this off, or why it won't go out?

What year Elantra?

What light? The light that looks something like this: (!) or a light that displays "TPMS"?

its the low tire (!) not the "TPMS" failure light. It blinks for about a minute, then stays on.

The sensor in the wheel might be bad. Are you sure the gauge you are using is accurate?

Yes... I even tried a brand new gauge.

Would the the sensor be covered with the 5yr/60K warranty?

Yes, it should be.

Seems like the vibrations from the car wash may have something to do with it. There are a number of things you can check for. But I would start with driving it for 20 minutes.

From the owner's manual:
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the system is not operating properly. The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash for approximately one minute and then remain continuously illuminated. This sequence will continue upon subsequent vehicle start-ups as long as the malfunction
exists. When the malfunction indicator is illuminated, the system may not be able to detect or signal low tire pressure as intended. TPMS malfunctions may occur for a variety of reasons, including the installation of replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning properly....

And:
Once the... TPMS sensor mounted on the replaced spare wheel is initiated by an authorized HYUNDAI dealer, the TPMS malfunction indicator and the low tire pressure telltale will extinguish within a few minutes of driving.

Other possibilities from the manual:

The TPMS malfunction indicator may be illuminated if the vehicle is moving around electric power supply cables or radios transmitter such as at police stations, government and public offices, broadcasting stations, military installations, airports, or transmitting towers, etc. This can interfere with normal operation of the Tire Pressure Monitoring System (TPMS).
• The TPMS malfunction indicator may illuminate if snow chains or some separately
purchased devices such as notebook computers, mobile charger, remote starter, navigation etc. are used in the vehicle. This can interfere with normal operation of the Tire Pressure Monitoring System (TPMS).

Solution
 

bad TPMS module

Isn't it peculiar that the control module went bad at that moment?

Is there a button I can press and hold down to shut the light off?