Warning Lights-Loose Gas cap?

2006 Prius w/75,000 on it with regular service

Filled up with gas Sunday night, drove a short distance, noticed these warning icons were lit up-master warning light, (O) w/! inside--brake, VSC, Check engine and Hybrid system.

Pulled over, gas cap not tight, so tightened that. Stopped 1 hr for dinner--had to eat anyway. Came back, same lights on. Drove 2 miles home, car seemed to drive fine.

Got up early on my day off, called dealership, they said it probably was the loose gas cap and to drive it for 3 trips of some distance and it should be fine. Drove 5 miles that day, no change

Tuesday morning, only the Master warning, check engine and hybrid sytem lights were on, drove 35 each way to work, car seemed to run fine, but on the trip home all the lights lit up again and then a fan sound came from the vent on the right rear passenger side--battery fan?

Ask me a cat health question and I could answer it, this I feel means a trip to the dealership for me but I'd like to go in armed with some info.

Thanks in advance, Teri

 

Have an 8:30am appt tomorrow...I'll need luck,thanks!

 

Sorry for the late update to my post about the warning lights...turned out it was the "main battery" failure and they replaced it under warrently--whew!!