Hello. I'm facing rear PDC in MK3 FL. It just stopped working one day. There is no sound and no visulisation on the screen.

I did research and: there is no DTC in VCDS (connection to module with no problems), front PDC is working, reverse light are on when reverse gear selected (normal short "beep" sound is heard as it was before), camera displays what should display. Test in VCDS turn on the beeper. Tried to disconnect the battery, updated infotament software.

I'll tried to hear or feel sensors as I was doing in other cars and can't hear or feel none of the sensors (front and rear). Tried to remove rear bumper and check all connections even though there was no sensor related error.

I'm out of ideas what cause the problem. Don't know if maybe some wiring from reverse switch to module (form module to sensors probably would caused an error).

Any hints?

What happens when you press the button on/off which disables rear sensors? It’s next to gear stick

 

I’ve never used it but I’d imagine it only disables it until next restart, but might be worth pressing it harder than usual to see if anything happens

Tried to press it many times. Short presses, long ones. Long press causes turning off braking assist during parking maneuvers. If it's off there is no "beep" sound when selecting reverse.

After resetting still no signals from rear sensors.

Problem solved. Maybe someone will find it helpfull. In my case at least one of the sensor was the cause. 

As I wrote earlier, I couldn't feel the "click" of sensors but checked once again and there was quiet but audible "click" sound. 

 

Troubleshooting based on decay time of sensors in VCDS. One of them had quite static time comparing to the rest (time was oscilating aroun 1ms, where one had almost constant 0,95ms). After replacing this one nothing changed in working of PDC but other sensor started to give static decay time. After replacing second one, PDC started to work. 

Oh...and info about rear buzzer. In Superb FL there is no rear buzzer - in prelift versions buzzer is in B pillar behind the driver, as in lift version same buzzer (near PDC module) is for front and rear PDC.