Parking sensors What next

[Brockuk]

I have a 2011 c220 w204 estate rear parking sensors given up 4 red lights and beep showing, scanned with icarsoft pro showed both outside sensors faulty, replaced them no difference, what next to try parktronic module or rear loom first.
Many thanks in advance for suggestions.

 

[mioba]

I car soft doesnt read sensors properly or the module - just says all fine.
I done a thread on this a while back.
Put it on live data and see which sensors read zero cm. When nothing there its 255cm. Get a helper to go round near each sensor as you look at the live data - then the fun starts of swapping good with bad.
It took me almost a day on my W220 and i was even thinking its the module.
I had 2 sensors out. Managed to get three of ebay the same colour for 15 each - MB wanted 162 each.