Strange noise

[Black_griffin6]

Hey guys, last night I heard a weird noise coming from my 09 Yaris LB.
The noise sounded like a buzzing noise, almost like a pump or something except the car was off and had been off for about 5 or so hours.
It was only on for a few minutes, and i've heard it before, but it sounds like it's coming from under the car.

I'm not really worried about it, I just wanna know what it is. :biggrin:

[henry33]

have you unlock the car and open the door and after that the sound appears ?
if so it will be fuel pump

[DARK AGE 53]

the next time you hear the noise remove your gas cap, I think you'll find the noise goes away.

[BLH]

My 2007 is the same way.
The Evaporative Fuel System does a check after sitting a few hours.
Yes it is the fuel pump running and if you remove the gas cap. The test may fail and you get a check engine light.

[NinjaPirate]

That would be creepy lol. Mine doesn't seem to do that. I went out tonight just before it's been turned off for 5 hours and listened for a lil while. (yeah I got nothing better to do :P)

maybe only on US delivered cars..?

[xtremist]

Hey guys, last night I heard a weird noise coming from my 09 Yaris LB.
The noise sounded like a buzzing noise, almost like a pump or something except the car was off and had been off for about 5 or so hours.
It was only on for a few minutes, and i've heard it before, but it sounds like it's coming from under the car.

I'm not really worried about it, I just wanna know what it is. :biggrin:
Black_griffin6, I got yaris sedan and I've always heard a buzzing sound only when I reached 100 kph but will be gone if I go beyond 120 or more. I'm also curious about that...:confused:

[DARK AGE 53]

My 2007 is the same way.
The Evaporative Fuel System does a check after sitting a few hours.
Yes it is the fuel pump running and if you remove the gas cap. The test may fail and you get a check engine light.

never heard of that, any TSB or anything showing that?

[BLH]

It is described in my 2007 Owners Manual on page viii and also was on a string tag hanging on my dash when I purchased it.

Basically about five hours after the car is turned off. It does a Leak Detection Test.
The fuel pump turns on and you may hear it running. As it checks for leaks.
My thoughts where it you caught it when testing. It could flag an error if you loosen the cap. I know the manual says to check you gas cap if the Check Engine Light comes on.

[Black_griffin6]

I thought it might be the fuel pump or something, but at the same time I didn't think it was the fuel pump because it didn't make any sense to me as to why it would be pumping fuel a few hours after the car had been turned off.

At first I thought it was some insect caught in my garage, since it sounded similar to that. Then I listened and it was coming from under the car.
Thanks for the answers guys. :thumbsup:

[yougojay]

I took the recyclables down to the garage about 2 hours ago, and mine came on and was humming/running for awhile. I knew I had heard about this before & I knew everything was cool. Kinda spooks you as it starts on its own. It was about 5pm and, yes, I had returned from the store 5 hours earlier...

[IllusionX]

wow.. strange i haven't seen this thread 4 years ago.

Both my 05 echo and my 07 yaris came with a cardboard attached to the shifter, saying that there may be noise coming from under the car 2 or more hours after the car is parked.