Parking sensor relay

[monument7]

Hi guys,
At my wits end here, i have a 2006 e280 s211 with a few queries.
Park sensors do not work at all and can't find the relay.
Also the glow plugs play up making it hard to start first thing and the coil sign comes up on the dash.
Finally does the auto gearbox oil need to be filled from below.
TIA
Dave

 

[Blobcat]

Parking sensors will be controlled by one of the SAM’s (Signal Acquisition Module) - they can get wet, open up and take a look. The sensors also fail due to water ingress.
Glow plug light coming back on is a sign that one (or more) of the plugs has failed (and/or the control module)
Yes, fill from below - change every ~37k miles