Five warning signs showed up on the dashboard and multi-information display. The fan for the hybrid battery pack started running all the time. A trip to the dealer determined that cell #5 in the battery pack was weak. Fortunately it was under warranty. Otherwise the service guy thought it would take $3,300 to replace it. He said it's the first time he's had to replace one of those cells. Mileage dropped by about 3 mpg recently. I'm blaming that on the bad cell. Warnings: /!\ + (!) + VSC + Check Engine + red car with "!" The dealer replaced it free within 24 hours and the car is running fine again.