i think its a wiring issue get it checked from a good mechanic,,, my friend's city 06 130k driven had this problem of shutting off engine and giving engine check,,, while driving on both cng and petrol,,,, then u hav to turn off the switch and turn it on again after a sec and it would start,,really annoying as it happened every 3-4 km's, we thought the coils need to be replaced but then my mechanic did told its a ecu issue so he took off the battery joined the +ve and -ve terminals of car for a few sec and attached the battery again in order to reset the ecu,,, the car is running gr8 ever since and the milage was also improved,,,
