my TPMS light comes on occasionally. and goes off.

not the low tire pressure light.

tires are at proper pressure.

i took it into tire shop when light was on and all tires read right pressure using their tpms reader. they did some sort of system reset and a little while later it comes on again.

how do i isolate which sensor is bad or if it is something else?

when the light is on, will each tire still give a low pressure light if they are low?

thanks

tom