Electronic Whistle

[BobbyPosh]

Can anybody tell me what this is? Toyota main dealer and local garage do not know. At a speed of 30mph or less, usually at the end of the day, after quite a lot of driving I get an electronic whistle in my 2002 1.8 Avensis Auto hatchback.

It seems related to the brake because it stops as soon as I touch the brake and returns when I take my foot off the brake. Often it starts when I go round a slow corner and it will disappear again for no known reason. Sometimes I can vary the pitch of the whistle by gently varying the pressure on the brake, almost play a tune! Sometimes it will continue a bit (quietly) even when I am stationary.

It is annoying if it just will not go away but usually it does after 20 minutes or so. The brake's efficiency is not affected , although I am a little concerned that something could be going wrong in the brakes that could prove significant. Servo? Trapped air? But it is an electronic sound, not a release of air pressure.

THIS IS NOT AN APRIL FOOL'S JOKE!