What does it mean if yout TPMS light comes on while your driving but turns off?

The LETTERS coming on means a code or several codes are stored in the TPMS control unit.The tire SYMBOL coming on and then going off after driven and tires warm up is pressure related. Typically if the control unit sees all tires below pressure threshold at any given time , it will turn on the letters and would just need to be cleared with a scanner. From your description , you may have a sensor that is failing , or you are using power adapter(s) for cell phone or some other device , that may be causing intermittent signal interference. For others out there that deal with reprogramming sensors , at least on newer Hondas' , it's becoming more common to see this problem. TO MUCH ELECTRONIC CRAP!....IMO...

that will happen as the air expands in tires,set all tire pressures at 36lbs and you will be fine