Warning sound

[goddo]

I hope one of you guys can help me with this?
I have a 2007my DB9 and when I started it up this morning there was a high pitched warning sound (it is like a whistle)that lasts for maybe five seconds, stops for a few seconds and then starts again. Same in D, P or R. There are no warning lights or messages showing on the instrument panel. The only thing that I can think of is that the car has not had a decent long run recently. Could it be a low battery warning although it started quite normally without any signs of being down on charge?

[drmw]

mine had a failure of the parking sensors which meant the beep would sound as and when it wanted. It needed a new control unit. Does it make that sort of noise?

[goddo]

drmw said:

mine had a failure of the parking sensors which meant the beep would sound as and when it wanted. It needed a new control unit. Does it make that sort of noise?

No, instead of short beeping sounds, this is more a continuous whistle sound for approx. five seconds

[yvr]

Alarm sounder backup battery starting to fail? Does the whistle come from behind the rear wheel?

[goddo]

yvr said:

Alarm sounder backup battery starting to fail? Does the whistle come from behind the rear wheel?

No, not from the rear of the car. This sounds as if it's coming from the dash somewhere.

[Billieray]

tyres air pressure check up?

[goddo]

Billieray said:

tyres air pressure check up?

I don't think this is the problem.
There is no warning light on the dash to say the TPMS is warning on low pressures.