Parking sensors not beepimg

[Sterny666]

So i finally decided to get round to fixing the parking sensors as they have never worked since I bought it. Upon inspection I found the predicatable water in the PDC module under tray! The module was beyond repair so I bought a second hand one with the same numbers as the original in the hope it wouldn't need to be coded. After replacing it I plugged in my BMW code reader erased all fault codes and checked the data stream. All sensors were now working but I wasn't getting any beeping sound. It also showed the acoustic generator as 0V so decided to unplug the speaker and check with a multi meter. This confirmed there was no power reaching the speaker. All cables seem fine and the fuse is ok so I'm well and truly stuck on what the problem could be? Could the second hand module be faulty? Or will it need coding for the speaker to work? No fault codes are showing up anymore. Any suggestions would be much appreciated

[MauiM3Mania]

Moved from BMW General sub-forum.