Thread: L322 Front parking sensors fault

My L322 front parking sensors don't work. According to the manual if a fault is detected by the PDC ECU in one sensor then all 4 are disabled. Thus I cannot listen at each one to ascertain which is one faulty. The manual also says that if a fault is detected the PDC led will flash and sound a 3 second warning tone, however, mine is not doing this ! The front internal sounder is OK. Is there a way I work out which one is at fault without paying the garage to use their diagnostic kit ? Thanks.

So, I’ve now tested each front sensor and checked its wiring. All found to be working/OK. I accessed the front 2 outer sensors quite easily via the wheel arch. The 2 inner sensors I gently prised out from the front with a small bladed screwdriver quite successfully. I then removed one of the known good rear inner sensors by pushing it out from the back of the rear bumper. This is easy by just reaching up underneath. Thus I was able to plug in each front sensor in turn to test them. No front or rear bumper removal necessary ! Since I have no flashing LED on the PDC switch nor any 3 second audible warning tone, I can only assume that my front sensors have been switched off at some earlier time via the IDS – do you agree?