2007 Elantra huyandai

No sensors come on? Did you mean that the check engine light does not come on?

Thank you for responding. I just bought the car middle of november and when it happened (2wks after I bought the car) I explained it to the dealership which I bought it from (it was not a hyundai dealership).. my car's senors light all lite up then the car had no power. It stopped. I then turn the engine back on and then it will drive. It first started happening when I would turn into the parking lot. Then very recently when I was going on a straight road going 80 mph. All the sensors lite up and then I had no power. It seems to happen every 2 weeks. Of note the engine light comes on and off. I took it back to the dealership and he said it was the gas cap. I took it to my regular mechanic as the engine light was on. and the reading said P001.. A camshaft position- timing over - advanced or system - performance bank 1. I showed this to the dealership and he said since the sensor light came back off he could not fix the car. Even though I showed him what my mechanic saw. I have taken it back to the Dealership and they have had the car since thursday evening. Of note the engine sensor light comes on and off. I really do not know what to do. Any help will be greatly appreciated.