Access rear park sensor module

[Wizzzzz]

Hi all. I need to check my rear park control module which, after a VCDS scan, looks like it may hav been disconnected when a Skoda towbar was fitted.

ive been told it sits behind the rear off side trim panel in the boot but can’t figure out how to remove or loosen the boot panel to access the module. I’ve googled for ages and can’t find anything on it

 

any help or advice would  be greatly appreciated 

 

TIA

[chimaera]

It's a pain in the arse to remove. Your best option is to go to https://erwin.skoda-auto.cz/erwin/showHome.do, pay for an hour's subscription, and download the service manual. For this particular job, you need the Body Work pdf, but an hour is enough time to download everything else for the car too.

[Wizzzzz]

Thanks for that Chimaera.

im almost tempted to cut an inspection hatch in the rear right side to just to check it out as it’s behind the door for the first aid kit. I’m hoping that someone can confirm where the module is placed so I can ensure I access that area and not 2 feet away but I can’t find any diagram. 

[chimaera]

It sits on the wheelarch pressing facing the rear, so it wouldn't be too far from the side of the storage compartment in the side. You can see it on the right in this picture I took during my towbar install.

 

Edited 30 September, 2021 by chimaera
Added picture

[Wizzzzz]

Thanks mate. I now owe you many beers🍻🍻

[Wizzzzz]

Hi again. Managed to access the park sensor module and it appears I am missing the centre connector plug which is showing on the previous pic. Unsure what that cable is or where it may be tied up. I'm trying to avoid removing all of the boot trim

Edited 1 October, 2021 by Wizzzzz
Add picture

[chimaera]

Do you have front parking sensors?

[Wizzzzz]

No just rear

[chimaera]

I just dug out the wiring diagrams to check what each connector is going. The black one on the far right is the connector for the rear parking sensors, so that's the one you need to be looking at for problems. The brown one in the middle on my photo is the connector for the front parking sensors, so if you don't have them there's no reason for it to be there.

 

Was there any response from the controller when it was scanned with VCDS? If not, there's a problem with the controller itself, the power supply to it, or the CANBUS lines are damaged. If it did respond, there's a problem with the wiring from the controller to the sensors. I'd be surprised if the CANBUS lines were damaged as the parking aid controller sits on the drivetrain CANBUS network and if the car is starting and driving normally it's unlikely there's damage there.

 

I'd start fault finding by checking the integrity of the wiring to the controller and from there to the sensors. Fuse 5 on the dashboard fuse panel is the one that powers the system, so check if that's ok first. It's also useful to pop out the fuse and see if there's power available on the top contact for it. At the controller, check that there's power available at pin 1 of the brown 16-pin connector: that's the power supply from the fuse. Probe from that pin to ground on a nearby earth point or some bare metal on the bodywork to see if it has power. Do a continuity check from pin 8 of that connector to ground as well to make sure there's no break in that wire. 

 

If everything on the power side checks out, I'd go to checking continuity on the connections between the parking sensors and the black connector.

Start with the leftmost sensor as that one is the master power supply for the 4 sensors. Check from the black connector at the controller to the connector on the sensor.

• Controller pin 11 to sensor pin 1 (red/green wire)
• Controller pin 5 to sensor pin 2 (blue/white wire)
• Controller pin 8 to sensor pin 3 (brown/green wire)

For the other three sensors, check continuity along the red/green wire between each connector (power supply) and the brown/green wire (earth/ground). For the signal wires, check continuity back to the controller connector:

• Controller pin 3 to centre left pin 2
• Controller pin 2 to centre right pin 2
• Controller pin 4 to rightmost pin 2

If everything has checked out so far, I'd suggest taking a look at the towing electrics that were fitted. If they're OE and were fitted properly there should be no impact on the parking sensors. OE electrics will also show up in a VCDS scan at address 69.

 

Skoda sell the electric kit and the towbar separately, so it's entirely possible for someone to fit a Skoda towbar with aftermarket electrics. If the OE electrics are fitted, you should find the controller attached inside the boot liner panel, on the left hand side of the boot beside the tailgate opening (more or less behind the light cluster). It possible for it to be fitted on the right hand side too (this would be normal for installing on LHD cars, and some people do it that way on RHD to avoid stripping out the boot liner on the left). If there are aftermarket electrics used, you'll need to track down how they were wired in and whether that could have disrupted or damaged the parking sensor system.

[Wizzzzz]

Is anyone aware of where I can identify the cable route to the buzzer which I believe is under the headliner. If it runs from the control module, I can try to locate the cables coming from the module plug cut and add in a new buzzer and se if the fault lies there.

id be happy to mount the replacement buzzer in the boot area.

[chimaera]

1 hour ago, Wizzzzz said:

Is anyone aware of where I can identify the cable route to the buzzer which I believe is under the headliner. If it runs from the control module, I can try to locate the cables coming from the module plug cut and add in a new buzzer and se if the fault lies there.

id be happy to mount the replacement buzzer in the boot area.

I don't think the buzzer is the issue based on what you've said. If it was just the buzzer you'd still have the display on the nav unit and the controller would show up on a diagnostic scan.

[Wizzzzz]

Cheers Chimaera. I’ll replace the module and see where we end up 👍👍

[Wizzzzz]

Sent you a PM Chimeara

[chimaera]

46 minutes ago, Wizzzzz said:

Cheers Chimaera. I’ll replace the module and see where we end up 👍👍

Why waste money on a new controller when you don't yet know what the problem is? Have you done any of the wiring checks I suggested yet? There are plenty of ways for this to be broken without the controller being the problem, especially when the car has a towbar fitted. Diagnose the fault properly rather than throwing money at it blindly.

[Gospodinov]

Guys, i will use this topic for my question if thats ok. Now i have only rear parking sensors and i want tk

[Gospodinov]

Guys, i will use this topic for my question if thats ok. Now i have only rear parking sensors and i want to add front as well. Do i have to change the module?