@Cultusxxx, thanks for raising the issue again dude.
@spectra, sorry dude its not actually a radiator sign, in fact its a check engine sign.
@Proverbial_Slang, I went to the workshop, the checked the battery terminals and other connections, and told everything seems well, and If the problem comes again I must come for a detailed checkup. and the next day the sign comes again, after that i am a little stuck in my work, so could not go for a detailed checkup. Now after vik_vik's advice I will first go to an expert CNG mechanic.
@vik_vik, dear can you share the details of that expert CNG mechanic? Name locations, contact no. etc... It will be helpful for many of us. Thanks