Freelander 2 (LR2) Parking sensor advice needed

Hi,
I'm trying to tackle a problem on my wife's 2009 LR2 with front and rear parking sensors - the problem is that they are not working. Yes, I have searched different forums etc and tried the tricks to diagnose but I'm running out of ideas so this is a last try before going to the stealers.

What I have done:
1. Turn the car on, put it into reverse and checked the sensors (both rear and front) for clicking and vibration - none of them do it.
2. Disconnected the fronts from the loom (LH side wheelarch) and checked the rears - still nothing.
3. The fuse in the boot is ok, changed it for good measure.
4. Connected an OBDII reader and checked for codes - the list is clean.

When I engage reverse the parking sensor button blinks a couple of times but doesn't stay on so obviously there is a fault somewhere.

Maybe anyone has tackled similar situation and has some advice for me.

Thanks in advance!

The PDC system needs a full system diagnostic read to say what is wrong. An OBD2 won't tell you anything that isn't engine related. I've got 3 missing sensors, and my diagnostic equipment tells me exactly which sensors are missing.