Microgo m8 E2 error how to fix 

Ive just picked one of these scooters up, with an issue... When i turn it on, The brake light is constantly flashing, and doesnt accelerate.... Sometimes E6 appears on screen,. But not all the time though... Probably 1 time out of 50 powers, it will show E6... But always just stuck with brake light flashing, and accelerator not responding.... I did double check all the connections.. A couple of times, it has worked... accelerated fine, until i turn it off... then it will continue to fault again...