Actually i once came across this problem. It happens after 2 months of buying brand new city. Servant left radiator cap open. I went far away. Went to hill station even, then back and started spinning a harsh driving where i found loss of power and change in noise of engine. Mean after about 2 hrs of real hard driving with AC on, at last that red light of over heating came on. I decided to go home and then check the problem. Before reaching home, it started blinking. Well went home safe n everything remained safe. Nothing unusual happened after that.
Purpose: Pani sar se nahi guzarta. 1st it turns on the light aur jab pani sar se guzarne lage, it starts blinking
Meray bhai jin shikayaat kay baray main aap nay zikar kiya hay to bad news for you "paani sar say guzar gaya hay", ab daikhna ye hay kay ghota kab lagta hay, "aap kee gaari ko aik bar attack ho chuka hay" yaani gaskit pay aik baar bad effect aa chuka hay !!!