for the past 5 days, when i start the car for the first time i get about a 5 second beep that seems to come from the dashboard area. no idiot lights come on and everything seems normal. even if i start the car another 50 times that day, it doesn't beep again until the next morning. anyone else have this?

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04 6MT sedan, black/willow

 

My guess is it's the low tire pressure warning chime. Should also be accompanied by a warning light. The manual says it will ring for about 10 seconds if sedan tire pressure is below 25 psi. The warning would occur in the morning because ambient temperatures are lowest then and the tires are cold. Pressure will rise as the car is driven and might not fall below 25 psi all day, so there wouldn't be any warning later in the day.

04 G35X

 

My '03.5 Sedan used to do the same thing, but it hasn't done it in a long time.
BTW, I do not have tire pressure monitor.

 

tire pressure is ok but one of the sensors may be on the blink. will have it checked at my 15k maintenance. thanks for the input guys.

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04 6MT sedan, black/willow