Does the low tire pressure let me know which tire is low on aire

When the TPMS light is staying on - using a quality tire pressure gauge - check air pressure in ALL tires - including the *spare* tire. Then you're good to go.

To answer your question, depending on the vehicle you can look in the driver information system and it may tell you which tire is low, but this it only good if the system has been programed after the tires have been rotated so that the system knows that the sensor say reading the right front wheel is on the right front at this time and not on the left rear. It is always good to have all the tires checked even the spare tire if your vehicle has one. That way the light isn't back on next week because one of the tires where just a little low this week. I hope this helps if you need more just let us know. Thanks Bobby