Hi I need some help /advice. My jeep renegade longitude has a problem with sound system which affects the parksense and sat nav. The front drivers speaker had stopped working and apparently this also affects the parksense and sat nav voice commands. Now I took my jeep to the place I got it from and they replaced the speaker and all worked fine. And now only two weeks later the same problem has occurred again but it's the front drivers side speaker not working and no parksense or sat nav voice commands. You can get music on the radio even though it says sound system unavailable! Could the problem actually be the head unit itself? Any help or advice would be much appreciated ?