Is there a known problem with air leaks from the TPMS? I consistently lose air slowly from one tire, without any obvious signs of damage/nail/etc. I see there is a tech bulletin on TPMS for 2013 TL but it gives no details beyond requirements for documentation by dealer...

 

The grommet itself may be leaking or the stem may just need tightening down . Buy a tool or just go to a Independent shop and ask them to torque down the stem

 

I had the same issue on one wheel and had to replace the mounting nut and seal. IIRC they were around $5.

 

In some cases, slow air leak could be from the bead seal, between the tire and the wheel.

 

See this Acura Service News article:

B15090E
Tire Pressure Sensor Oxidation Causes Slow Leak

https://acurazine.com/forums/third-g.../#post15570537

 

swap the tpms out to another tire to see if it still leaks.

 

Go to any tire shop, they will submerge it in a tub and see the air bubbles = find the culprit. Or (Discount Tire) if its a nail/screw they will patch for free.(as long as you have good thread)

 

I am having this issue with my front driver side tire, it started this winter. The tire is loosing 1 psi per day and when it goes down to 27 psi I get a warning light in the dashboard. I took the car to the dealership and they found the tire and rim are perfect, I suggested to take a look at the bulletin that EE4Life shared and they replaced the tpms grommet, tmps looks fine. The grommet replacement did not fix the problem, tire is still loosing 1 psi/day. The dealership called me to follow up and asked me to bring the car back to have a different technician look at it. It is really annoying to add air every 2-3 days.

 

Like thoiboi mentioned, check your valve stem make sure it's tighten down properly. I was losing air too. I sprayed some soapy water on it and it started bubbling up from an air leak. Bought a little tool from Walmart for like 3 bucks and my tire pressure hasn't gone down since.