Hi all, 

 

I wanted to install front parking sensors to my 2018 SE L (comes only with rear sensors) but obviously I underestimated the complexity of the job (hey, I'm an ECU engineer right - should be walk in the park).

 

- Replaced the existing 4k PDC control unit with 8k PDC control unit

- Replaced the dash switch panel so now I have the parking aid activation / deactivation switch, wired it to PDC control unit (both illumination and function works) 

- Added a buzzer for front sensors, wired it to PDC control unit (buzzer works during VCDS output test)

- I haven't installed 4x sensors in the front bumper yet as I wanted to make sure that everything works before installation. I've wired 4x front sensors externally (so all sensors are in a box but correctly wired to PDC unit). 

 

Problem is when I put in reverse gear (or activate park assist manually via switch), only rear sensors seems to work, front sensors show distance about 1 seconds, then park aid system error pops up. VCDS shows "internal system fault" DTCs for all 4 front sensors (B10FX 04 [009]). 

Everything is wired according to system circuit diagrams so I'm not expecting wiring to be the issue, however there are too many new components so diagnosis is not easy. 

 

Any help is appreciated if you can, my questions :

 

1) Does anyone know the pin layout of VAG sensors ? Not crystal clear in wiring diagram but I assumed : B+ / signal / Ground as 1/2/3  

2) Internal system fault DTC really doesn't help for diagnosis but does anyone know what exactly does it mean ? 

3) Probably silly question but, sensors are not fit in place (even if wiring is correct) - could that somehow be the root cause ? 

4) Even if 1 sensor is faulty, does it cause all 4 sensors' internal system fault DTC to be raised ? 
5) When I "upgrade" parking aid system from rear only to front & rear, do I have to change the coding of other control units such as gateway or head unit ? 

5) Any recommendations for next steps ? Frankly I'm out of ideas as I tried different codings / harness open/short circuit checks etc...

 

Thanks for any help. 

 

Welcome to the forum,

 

I tackled the problem from another direction, as I had existing system of F&R parking, where the rear developed a fault.  A faulty rear loom (corrosion) caused only some of the sensors to go down (I could get measurements from some of them only)

 

It lead me to make this post here, as I didn't need help in sorting it, but if you take a look you will see that each sensor has a common + and - shared by all, with only the s (signal) going to each individually.

https://www.briskoda.net/forums/topic/505798-basic-how-to-read-wiring-diagrams/

 

So you are correct that Pin 1 = + feed (single common shared) Pin 2 = s for signal with a wire dedicated to each sensor, finally Pin 3 = - Earth shared on a single feed wire

 

I had issues myself, as I sourced some new rear sensors from Aliexpress that matched perfectly the VAG OEM numbers, and not one worked at all.  So were your sensors from there, or from VAG/donor scrap car?

 

You shouldn't need to touch Gateway coding as it's aware already of you having PDC system, though might need coding elsewhere.

With the forward movement, the system works at low speed, so it must be talking to another system via CANbus for sure, as it activates up to xx km/h in forward.

Thanks varoom, my sensors are from ebay - 4 of them only 28£ so probably similar sourcing to your Aliexpress ones .

 

I think I'll order another 4 from skoda-parts.com - they seem to have relatively better quality OEM sensors. 

varoom, thanks a lot - I got 4x new sensors (allegedly removed from a Tiguan MK2) and it works now! I shouldn't have gone for the cheap ones.

 

Now I just need to remove front bumper (still no idea how to remove that 2nd screw just under the headlights  ), find a nice opening between engine bay and cabin etc...

Good luck in getting this finished off 🤞

Job done - I've used the blanking grommet which is used to cover the unused clutch master cylinder hole on dash panel.

 

When I find time I'd like to polish my .ppt and put here as a guide. 

On 24/10/2022 at 21:36, ronery said:

Job done - I've used the blanking grommet which is used to cover the unused clutch master cylinder hole on dash panel.

 

When I find time I'd like to polish my .ppt and put here as a guide. 

Did you ever find time to make the guide? I’m looking to do this on our my2021 kodiaq se