Hi everyone,

Earlier this year I purchased a 5J (2007 so awkward crossover year) fabia, making it the fourth Skoda outside the house. I think we've got a problem!

She's a beauty all blacked out and elegance spec 1.9TDI so best engine and all the bells and whistles for its time. But have sorted out quite a few bits on it to get it where it is.

Im now onto the fairly minor niggles. Parking sensors being my next adventure. Its the only diag codes I have for the car now (other than aftermarket radio) and I would like to have them working. When I run a scan in VCDS it comes back as all sensors mechanical failure. Which says to me its unlikely a sensor issue and likely an issue with ground or supplied 12v power. Unless they are wired in such a way that one sensor dying brings them all offline, but I find that unlikely otherwise whats the point in having separate diag codes for each!

Obviously the first thing I've done is check all the fuses relating to parking sensors. No luck there.

I'm just here to ask before I spend ages poking around with a multi meter, are there any common faults with these sensors I should check first? Does anyone know where the sensors ground to and where the wires run for them? I'm thinking tomorrow morning I will be pulling most of the boot trim out and having a hunt for their incoming 12v and ground as I can see them entering the car towards the center of the bumper assuming into the boot.

Any info helpful. Many thanks :)

Heres my VCDS export:

Edited 8 November, 20258 Nov by Space_Cow
add image

You might have a problem with a ground as mentioned, also just a tip a mate was convinced his were broken and he forgot to leave the ingnition on and the car in reverse just saying, the multi plug on mine was in the nearside rear in the boot area about a foot or so from the rear boot interior light , the connection some how had corroded inside the plug female part but i manafed to clean it with WD and then used the old favorite vasaline, on mine it was the MK2 but was a 2008/58 plate so don't know if yours might be different, it still didn't work correctly but after this it did bleep when selecting reverse. I did have it checked out and it came back that the sesors on the one side were not working ,they told me it was the off side but once i had taken the bumper off to replace them i was not convinced so used a multi meter on them guess what they were ok it turned out to be the nearside outer sensor that had gone,so it seems the VCD readout worked the wrong way around, I did purchase a genuine sensor whichh was around £80 at the time but was gutted that it only came in black and had to spray it myself, also had to cut the old sensor off and use fibre glass mat to fix the new sensor ion place but i see now people use baking sods and super glue with a little mess looks a better job

1 hour ago, Murdockman said:

You might have a problem with a ground as mentioned, also just a tip a mate was convinced his were broken and he forgot to leave the ingnition on and the car in reverse just saying, the multi plug on mine was in the nearside rear in the boot area about a foot or so from the rear boot interior light , the connection some how had corroded inside the plug female part but i manafed to clean it with WD and then used the old favorite vasaline, on mine it was the MK2 but was a 2008/58 plate so don't know if yours might be different, it still didn't work correctly but after this it did bleep when selecting reverse. I did have it checked out and it came back that the sesors on the one side were not working ,they told me it was the off side but once i had taken the bumper off to replace them i was not convinced so used a multi meter on them guess what they were ok it turned out to be the nearside outer sensor that had gone,so it seems the VCD readout worked the wrong way around, I did purchase a genuine sensor whichh was around £80 at the time but was gutted that it only came in black and had to spray it myself, also had to cut the old sensor off and use fibre glass mat to fix the new sensor ion place but i see now people use baking sods and super glue with a little mess looks a better job

Nice one mate thanks for that.

The area you describe the connection to be is suspect cus the boot light there is also out so possible corrosion or something has gone on there. Il have to take that boot trim off then. I get the solid tone whenever I go into reverse and clearing the codes they re appear once ive been into reverse so I deffo know the sensor's connections are kaput but until I fix that I've got no way to know if any sensors are kaput. If I get to swapping any sensors il make sure not to glue them until ive verified its the correct side.

This connection then is suspect number 1. Its just a question of if any of the sensors are broken once I fix that. Hopefully VCDS will show me

Yes they should then show up that they are not working but as mentioned the VCD's some times throw a wobble and tell you the wrong side is gone but it might only be one sensor, some one once told me but i have never tried this method you put the car in reverse with ing on then go to the sensor one by one but try to keep out of its pick up area and put your index finger over the round part and you should hear the sensor click, if it clicks it's working thinking about it could be a trick to try the outer ones from the side because yu can stand and reach out by the side of the car and perhaps try the other sensors from inside the hatch area and just stick your arm out, never tried this keep meaning to but always have stuff in the boot and we now have a MK3 estate that has a reverse camera as well as the sensors so not really worred if the sensors pack in the camera is pretty good with the guide lines on the front screen

12 hours ago, Murdockman said:

Yes they should then show up that they are not working but as mentioned the VCD's some times throw a wobble and tell you the wrong side is gone but it might only be one sensor, some one once told me but i have never tried this method you put the car in reverse with ing on then go to the sensor one by one but try to keep out of its pick up area and put your index finger over the round part and you should hear the sensor click, if it clicks it's working thinking about it could be a trick to try the outer ones from the side because yu can stand and reach out by the side of the car and perhaps try the other sensors from inside the hatch area and just stick your arm out, never tried this keep meaning to but always have stuff in the boot and we now have a MK3 estate that has a reverse camera as well as the sensors so not really worred if the sensors pack in the camera is pretty good with the guide lines on the front screen

12 hours ago, Murdockman said:

Yes they should then show up that they are not working but as mentioned the VCD's some times throw a wobble and tell you the wrong side is gone but it might only be one sensor, some one once told me but i have never tried this method you put the car in reverse with ing on then go to the sensor one by one but try to keep out of its pick up area and put your index finger over the round part and you should hear the sensor click, if it clicks it's working thinking about it could be a trick to try the outer ones from the side because yu can stand and reach out by the side of the car and perhaps try the other sensors from inside the hatch area and just stick your arm out, never tried this keep meaning to but always have stuff in the boot and we now have a MK3 estate that has a reverse camera as well as the sensors so not really worred if the sensors pack in the camera is pretty good with the guide lines on the front screen

12 hours ago, Murdockman said:

Yes they should then show up that they are not working but as mentioned the VCD's some times throw a wobble and tell you the wrong side is gone but it might only be one sensor, some one once told me but i have never tried this method you put the car in reverse with ing on then go to the sensor one by one but try to keep out of its pick up area and put your index finger over the round part and you should hear the sensor click, if it clicks it's working thinking about it could be a trick to try the outer ones from the side because yu can stand and reach out by the side of the car and perhaps try the other sensors from inside the hatch area and just stick your arm out, never tried this keep meaning to but always have stuff in the boot and we now have a MK3 estate that has a reverse camera as well as the sensors so not really worred if the sensors pack in the camera is pretty good with the guide lines on the front screen

No corrosion on my unit but measuring the input side to the PDC module is interesting. Some vague information online tells me the blue black stripe wire is likely reverse signal which I can see a blue black coming off the reverse light so seems to check out (assuming that's where the signal is coming from). Engine off ignition on, pos2 in reverse 0V, engine on 2V. My reverse light works. So I'm just tracing that wire back now. Measured outgoing from the reverse light at 12v. Although I can't find exactly where the splice is at the moment. My feelings are it's buried deep in that car

I don't suppose anyone has a pin out. My pdc is PN:

5j0919283

Edited 9 November, 20259 Nov by Space_Cow

Well never mind.

Brown on mine was the 12v reverse signal. Despite being ground almost everywhere else in the car!

I couldnt find a pinout, in the end I verified I could find a 12V constant power (red yellow), 12v reverse signal (brown) coming into the PDC and that I was getting 12V on the output side out of almost all pins other than maybe 2 or 3 which seemed normal. So problem exists on the sensor lines after the PDC as far as I can tell. Maybe all 4 are just dead at once! Or theres a break in the line somewhere. Il have the bumper off some other time its freezing!