Oh, that's kind of a scary message. I know how much I freaked out when mine recently died on me (in the middle of the road, no less).
Spent a week biting my nails and pulling my hair out, waiting for Tesla Service Center to get back to me on how much it was going to cost to get it back on the road again.
Message should read - "$$$ Powertrain Problem - Restart When Safe $$$"