Disco 2 PDC PROBLEMS

Hi folks.
Only second time here and am looking for some help with my 04 disco td5 auto.
PDC worked fine then sound went wobbly, faint , then just stopped working.
Orange light on dash flashes. Tested speaker and it is fine. With key in positiin 2 and put in reverse, checked for power coming from pdc ecu, hitting 9.9v with engine not running.also can hear Clicking from all four rear sensors.
What else can I check and what can the problem be! All suggestions welcome.
I am reluctant to take a shotgun approach and just replace parts without a clear direction.

Any help is much appreciated.
Thanks.
T

Hi, some questions to clarify:
1. which orange light on dash is flashing?
2.how did you test the speaker to conclude it's OK?
3. where exactly did you get that 9.9V?

Orange light on pdc enable/disable switch on dash
Speaker tested with 9v battery to speaker terminals to hear crackle/hum sound
Voltage read from connector that speaker slots into

Thanks.
T

Having read your first post on the AG board, you reckon that you could hear each bumper mounted sensor clicking, which is usually accepted as a quick check that each one is working.
There's very little an owner can do with the system by the look of it, basically it comprises of the four sensors, the sounder, the dashboard switch, the little orange "tell-tale" light and the PDC ECU.
The power for the PDC system is via the fuse F16 (15 Amp) in the passenger's compartment fuse board, the same fuse as feeds the radio. The activation of the system is by sensing the reversing light circuit so that it starts working when the reverse lights are on.

From RAVE:-

Diagnostics
The PDC ECU has no diagnostic connection to enable faults to be retrieved using TestBook/T4. An on-board diagnostic routine monitors the system and alerts the driver to a system fault by emitting a tone from the sounder.
If a PDC system fault has occurred, the sounder will emit a continuous tone for 3 seconds and the PDC switch LED will flash continuously when reverse gear is selected.

That being the case, I would say that a replacement PDC ECU (Pt. no. YWC000790) might be in order. There is currently one on ebay:-
http://www.ebay.co.uk/itm/LAND-ROVE...D5+4x4&hash=item4d45ac2581:g:mw4AAOSwjXRXX-x0