Hi Varun..I was told when we purchased our's that the handle sensors can sometimes fail to read if the handles are dirty inside..very wet..or your hands are covered with dirt,oil etc..we have never had an issue with the sensors personally so don't know if the info is accurate..may be worth dropping into your local Toyota dealer to have them suggest solutions...another thought is the fob, as that is all the sensors are reading...I changed both fob batteries when we bought our Presara..always good to know they have fresh batteries
Hope you find a solution, and apart from that issue your ride is sweet
KAA