I have a similar problem on my 2.7d XS 2007. The led above my head is amber though, but the fuse ( 29 in the cabin fuse box) is ok and and there is no sound from the sensors. There is no sound in the cabin. I have also pulled the connection plugs out of the module in the boot and refitted them. But still no sound. I assume its the module as well . Stratstone have quoted £95 for a new module.