W164 electrical glitches

[Grandad010]

Hiya Guys
Purchased a 2009 320ML in May and in all honesty it's bee fairly trouble free motoring. Just about to turn 150k miles (not that you'd notice) I've got a couple of things I want to try and sort:
1) Parktronic - doesn't work at all, no lights or beeps, starting point would be great
2) Heated seats don't work again no function from the buttons
3) Rear speakers don't work along with passenger rear door central locking

If anyone can shed any light on any of the subjects I'd be most appreciative
Here's a recent picture of my car

 

[harrye500]

Welcome, I'd say a good start would be to check the fuses relevant to the issues you have. Process of elimination with simplest possible cause first.

 

[mattkh]

clean the parking sensors

 

[mattkh]

passenger rear door central locking
Is it the offside or the nearside that is not working ...?

 

[Grandad010]

UK Nearside (passenger)

 

[mattkh]

UK Nearside (passenger)

Thanks.
Given that it is the nearside, I would look at the cables going from the pillar to the door, the reason being greater open/close compared to the offside door.