week ago i got twice warning message , engine is overheated so i turned the engine off and checked under the hood, coolant was full, everything seems to be good. I started the car and there is no more warning light or anything, what can be wrong ??

check to see that your fans cycle on and off.

yeah i checked and it was on at that time

does it cycle off or does it stay on?

Do this with the ac off.

it does stay on with a/c on, but I'll try tomorrow w/o a/c

I have had the exact same thing happen to my car for the last two days. It only happens in the morning, on the way home from work after the car sits for ~8 hours I get no warnings or alarms as I drive home. Were you able to determine the cause of the error? I'm thinking that may be the engine coolant temperature sensor is faulty, or may be the thermostat isn't opening up in the morning.

if the fan is working then your best bet is thermostat sticking. BTW make sure the fan is Working when you get that message, as my fan would work only until it got really hot, then it would shut off causing engine to overheat.

The SA just called and I'm getting the water pump replaced. Thank goodness for the CPO warranty! The w/p has a price of $500 + additional parts + labor.

I never would have guessed that it was the water pump. I guess by restarting the car the pump was tricked into starting.