I have a Ford Mondeo mk 4 2012. I have owned it for 5 years with nothing major untoward happening. Two days ago we realised that the car radio had turned itself on as it was sitting on the drive. It was showing on the display FM Radio Derby; we live in Somerset but I know the car’s only previous owner lived in the Derby area! Although it started OK I was concerned for the battery and took it for a good 20 minute drive. During that time the radio constantly turned itself on and off and  always reverted back to FM Radio Derby on the display. I’m sure it wasn’t Radio Derby actually playing but a station more local to us using the same frequency. I spoke with my village garage (where I now take it for mechanical servicing) and was advised to visit a company in Taunton that has a local name for dealing with car audio issues. They were able to look at it the next day. As I drove it in there, the same thing was happening. Their report reads “Carried out diagnostic fault code read – no faults stored. Unable to confirm concern. Suspect internal stereo fault or software issue. Advise contacting Ford dealer before further work carried out.” Since that initial occasion, it hasn’t (yet) turned itself on again.

In principle I am happy to refer it to the local dealer (from whom I bought it), but not confident of receiving a reasonably priced service with a sensible explanation of what is wrong and what needs to be done.    

Has anyone out there experienced a similar issue and if so, how was it sorted?

I can now update my original posting which might be helpful for anyone who experiences anything similar. With the Christmas weekend looming and the radio having come on again overnight of its own accord, I decided to try and deactivate the radio. I’m no mechanic and did not fancy disconnecting the battery, but decided to look at any fuses that according to the handbook linked to the audio unit. There appeared to be three – one in the boot fuse box, one in the box under the dashboard and one in the engine fuse box. I removed the ones in the boot and the engine boxes quite easily. The box under the dashboard was awkward to get at and awkward to open and I gave up on that one. However having removed two fuses the radio was clearly dead when I tried to operate it. So that gave us a peaceful long weekend. On Tuesday 29 December I thought I had better ‘bite  the bullet’ and phone the Ford dealer and book it in. Very fortunately the phone was answered by one of the technicians, who was covering the desk when the usual chap had his lunch. He explained that they would run a computer diagnostic test. If that didn’t show anything they would disconnect the battery, leave it for 30 minutes or so and reconnect again and try it. (I might have got those two options the wrong way round). If both of those failed, then they would remove the unit and send it off to Sony who would either repair it or decide it needed replacing. He suggested I could disconnect the battery myself, but when I said that I had removed a couple of fuses and had thereby disconnected the radio, he said that was as good as and suggested I reinsert them and try it and only then book it in if the problem was still there. So I reinserted the fuses and lo and behold, apart from the first time coming back on in FM it has been fine ever since. I have waited before posting this in order to give it a reasonable chance and also to have driven several times. So all good at present. I feel I was fortunate to have spoken with the Ford technician who was happy to discuss with me rather than automatically just booking it in.  Why it happened in the first place remains a mystery.