Central Locking & Tailgate failure

cian.obrn

New Member
VIP Member
Good afternoon all,

I am posting this issue to try and get some clarity on the next steps with my tailgate and central locking.

Concerning a 2018 T6 Panel van in the throws of a conversion, For the past 4-6 months, the central locking has not been working, and the tailgate electronic switch has not been opening from the outside, only manually on inside can the door be opened, by pulling the wire up, which is a super annoying when i get out of the ocean after a surf wet, and have to climb inside dripping wet to open the doors to change and put my board away..

Anyway i have had a couple of people look whilst performing other jobs, and have been unable to diagnose or fix.

I have just spent the last 2 days having a crack myself, and have got pretty far in terms of what is/isnt happening.

Essentially the components all failed around the same time, possibly the same time (i live in Byron Bay Aus, which is possibly one of the safest neighbourhoods in the world so i never lock my car, so i dont know exactly when the central locking failed).
With regards to the central locking, The Key Fob still blinks when pressed, the indicators still blink when pressed, if i long press the key fob it still winds the windows up or down (awesome tip if you didnt know that one), essentially it does everything except operate the locks. I can even still hear some activity clicks in the BCM when pressed, just doesnt lock or unlock the car.
I have had the seats out yesterday, the florr lining too, and checked the wiring extensively for the corrosion, as i could literally throw a rock into the ocean from my house this was my first thought, but the wires all look brand new, and this issue seemed to only be on the T5s.. Havent seen a T6 facing the issue. So just plain exhausted all avenues here.

Concerning the Tailgate switch, again i believe these two guys failed around the same time. There are 2 parts to the electronic tai;lgate switch, the button itself, andf the motor to release the door.
I have tried by passing the switch, and the motor itself didnt fire when i did this. SO... I still wasnt convinced it was the motor, so i removed it entirely fromt he vehicle and wired it to a 12v battery and it still fired, so its working. The signal just isnt getting back to the motor from where the switch sends it.

So essentially im settling on the idea that the tailgate and locking switches are getting signal to fire from somewhere... Im wondering if this is the BCM? Does the BCM control both of these things, and if a module in the BCM has gone, can i fix this myself, or do i need to purchase a new one? I cant find any info on the BCM functionaility online, so just looking for some assistance with this or any thoughts formt he community on what this might be!
Wow that was a long one! Thank you for taking the time to read and any input greatly appreciated.

Cian
 
Have you got something that can read fault codes, because that would be useful to see what the electronics thinks is going on.

If you take out VIP Membership to the forum you will also have access to the wiring diagram downloads that will help you trace the wiring and check for any breakages.

Is there any indication the van thinks a door is open due to a failed switch?
 
Have you got something that can read fault codes, because that would be useful to see what the electronics thinks is going on.

If you take out VIP Membership to the forum you will also have access to the wiring diagram downloads that will help you trace the wiring and check for any breakages.

Is there any indication the van thinks a door is open due to a failed switch?
Thanks so much for the response. Something to read fault codes i think is the next step. I have been looking briefly at this, i think thats probably the direction ill head next; do a little research on what the best module to purchase is.
Also yes the VIP membership is something ill take out after finishing this response, again thanks fr the reply.
 
If you just want to read codes the basic Carista or OBDEleven are well regarded and not too expensive.

If you need to get into detailed diagnosis you may need the richer data and freeze frame data something advanced like VCDS can provide - the other "advantage" of VCDS is there are a number of helpful folks around used to reading the data who may be able to help.

For now I'd get something simple to read the codes and then decide where to invest in diagnostics if needed later, don't dive in and buy an expensive mid range.solution and then find you need VCDS anyway.
 
So i ordered the OBD Eleven.. pretty decent for the price.. Its giving me the fault code:
central locking 03396
Supply voltage terminal 30

Which at least has given me something else to follow up and look into. Looks like a fuse or wiring issue coming out of that location
 
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