A TPMS light that stays on solid usually means a sensor's battery has died or a sensor was damaged in a recent tire change; a blinking light means the system isn't receiving a signal from one or more wheels at all. San Antonio Tire Shop diagnoses which one it is and replaces sensors at 4510 W Commerce St.
Two different lights mean two different problems. A solid TPMS icon means one tire is reading outside the correct pressure range — check it, air it up or down, and the light usually clears on its own once the pressure's corrected. A light that won't clear even after every tire is confirmed at the right pressure, or one that's blinking, means a sensor itself has failed — most often the battery, which is sealed inside the sensor and isn't something that gets replaced on its own.
Sensors also get damaged during a routine tire change if a valve stem tool catches one wrong, which is why it's worth mentioning if the light came on right after a tire swap somewhere else. That timing usually points straight to the cause instead of a longer diagnostic.
Does a new tire always need a new TPMS sensor?
No — the sensor lives in the wheel, not the tire, so a tire swap alone doesn't touch it. It only needs replacing if it's already failed, if the valve stem it's built into is cracked or corroded, or if it gets damaged during the dismount. A sensor that's working fine gets reused on the new tire without a second thought.
What happens after a new sensor goes in?
The vehicle's computer has to be told a new sensor exists — that's the relearn step, and skipping it means the light stays on even with a perfectly good sensor installed. Some vehicles relearn automatically after a short drive; others need the relearn triggered with a tool before the light will clear. Either way, the job isn't finished until the light's actually off, not just the part swapped.
Can I just ignore the light?
You can drive with it on, but you're driving without the one system that tells you a tire's losing air before it's a problem on the highway. If it's been on for more than a few days, it's worth having it looked at rather than waiting for a slow leak to become a flat.
How much does a TPMS sensor replacement cost?
It depends on the sensor type your vehicle uses and whether one sensor needs replacing or the full set — call (830) 251-4817 and we'll quote it once we know the vehicle and how many sensors are actually bad.
Will the light turn off right away after the sensor's replaced?
Only after the relearn procedure runs, whether that's an automatic drive cycle or a tool-triggered relearn done in the bay. If the light's still on when you leave, that's not normal — come back.
Can a TPMS sensor be repaired instead of replaced?
No — the sensor is a sealed unit with a battery inside it, so a failed sensor gets replaced, not repaired. The valve stem it's mounted to is the only serviceable part, and that gets replaced routinely at every tire change regardless of the sensor's condition.