I keep my tires properly inflated to 36 PSI here in florida... on cold days my TPSM usually comes on... when i check my pressure all 3 tires are at 34 PSI but my rear left has dropped to 32PSI.

What would cause this one tire to lose pressure more than the others? Theres no big leak because i last filled up my tires a month or so ago.

Chances are its either your valve, or you have a slow leak in the tire. Sometimes the bead with the rim is the culprit.

The TPSM will go off if all or one of the tires drops more than a couple lbs.

Its normal for the tires to loose pressure when the temp drops.

its normal when its cold... when it gets below 30 mine with go off but when the day gets warmer it turns off...

I had the same issue shortly after I had my Volks installed left front kept
losing air. Took my car back to the tire shop where they put the tire/wheel
in water barrel and noticed the leak coming from the tire bead. After breaking
the tire they discovered a sticker on the inside of the wheel close to the
leak point....removed the sticker....problem solved! Tire wasn't seating
correctly.

Mine did this last week, it wasn't really that cold only about 45 and it came on. I checked and all the tires were the same pressure and then I decided to just drive it and it went off by the time I got to work, it was 73 that day. It's never done it before so I'm not gonna worry about it.
Lisa

pressures fluctuate depending on heat

hot = pressure rises
cold = pressure drops

the change is very minor, but it's there, and it might be enough to throw on the TPMS light

+1 fill your tires when they are cold