Auris Sat Nav Issues

[cy457]

I have a 2007 auris with the intergrated satnav and the problem is the whole unit loses power and switches itself off but not in the same way as if you were to cut the ignition.

When the power is lost it is though there has been a power cut and an audible noise is heard through the Speakers which is distracting.

The unit then powers up and operates perfectly for several minutes before losing power again.

It continues to do this and the timing is sporadic.

Any suggestions.