If it were mine, I would start with the flasher switch. Maybe the switch is bad or has a loose wire(s) causing a momentary close that causes the flash. Maybe over slight bumps or certain vibration. Also, I would go from that to the flasher relay to make sure it is seated well and wires to and from are correct and tight. That is where I would start. If it's still under warranty, have the dealer check those things. Good luck.