Random Noise When Parked

[77tcb]

Recently purchased a used 2014 RX 350 F Sport,  when I walk into the garage I sometimes hear what sounds like an electric motor running somewhere in the vehicle. Any thoughts? 

[TrevC]

How long after parking it in the garage do you hear the noise?

 

[grhack]

Several hours, overnight

[1990LS400]

It's a "feature" of all/most vehicles made by Toyota.

The following text is from the Toyota Venza owners manual:

" Approximately five hours after the engine is turned off, you may hear sound coming from under the vehicle for several minutes. This is the sound of a fuel evaporation leakage check and, it does not indicate a malfunction. "

The first time I heard it on one of our Toyotas, I opened a garage door thinking the buzzing was coming from outside.  Nope, it was just the emission system doing a self check.