Mine quit working after we returned in October having been gone all summer. It doesn't work even after 2 consecutive hourlong highway drives. The car sits all summer in our garage connected to a battery maintainer. Could it be that the maintainer doesn't charge the auto-start battery and that has damaged the it? Both batteries are now over 5 years old so maybe it's just time to replace them.
The owner's manual is no help since the Drive-E engine is not included in my manual.