I have a 2004 with 25K miles. Every couple of weeks when I push the power button to start the car the dreaded triangle appears along with the check engine light and the brake light. A couple of months ago this happened when I was close to the dealer so I drove into the service department, turned off the car, and got a service technician to look at it. To my dismay, when he powered it up the lights did not appear. So I left. Then it started to happen every couple of weeks and to solve the immediate problem I would drive a couple of miles, power down, power up and the lights would not come on again. I called the dealer and was told the next time it happens bring it in and DO NOT TURN IT OFF! It happened last week and I immediately went to the dealer. They had a technician ready to plug in his analyzer. They kept it overnight and checked it again in the morning. The trouble code of concern turned out to be P0560. He traced the problem to a faulty High Voltage Battery ECU not telling the car to charge the battery. It had to be ordered and was installed yesterday. I hope this solves it!