W220 200MY Strange Key/Locking/Radio behaviour

[abl567]

My S500 is behaving strangely. Recently while driving, having started the car with the Keyless Go (The old type with he seperate key card) the radio turned itself off. I stopped and restarted only for it to do it again the turn on and off randomly a few times. I stopped and the car wouldn't lock with the keyfob, or the keyless button on the door handle.
I locked it with the key manually then it wouldn't respond to the key fob or keyless go, giving a key card not recognised error on the dash.
Now it's just random, sometimes all is fine, sometimes key fob only, sometime nothing but key in the barrel will get me in.
Once it it starts and runs fine.
Could it be the battery on it's way out even though it's starting fine?
I've done a full scan and no errors on audio/command or Keyless go modules?

[abl567]

Update, now occasionally the radio will turn on, but no sound. Still random, still in conjunction with keyless/keyfob locking confusion.
I'm charging the battery overnight to see if that helps????

[John Green]

I presume you have tried new batteries in the key fob?

[abl567]

Yes, and the key card batteries changed.
It's no longer random, now neither the fob or the key card will lock or unlock the car and the radio/command is dead.
From what I can find online the SAM in the boot controls both. I've checked all fuses under the back seat and none are blown.
I'll pull the trim in the boot and see if I can see anything untoward

Charging the battery (car battery) didn't help

[John Green]

From what I can find online the SAM in the boot controls both. I've checked all fuses under the back seat and none are blown.

We have seen multiple issues with modules of various types in the boot getting wet from leaks and giving all sorts of issues.

[abl567]

No moisture at all found, dry as a bone.
And nothing visibly untoward, I have no idea where to turn

[abl567]

Now i've discovered the fob will work if I hold it directly on the IR square on the door handle, either drivers or passengers side. And I mean in contact with the handle.
Still no keyless go, key card not recognised error on dash, and still no radio/CD/nav/command. ????
Anyone have a recommendation of who to take it to close to Seven Hills, NSW? Or is a holiday in CBR on the cards?
I'm going to have to start driving the 6.3 daily