Central Locking Not Working on Internal Switches

[jilesA]

Hi, I'm new to this forum, I have searched for this issue, but nothing seems quite the same as my current concern:

I have a Caravelle 2016 T6. I disconnected the battery while checking other things on the vehicle, but when I reconnected, the central locking system stopped working (it was working fine prior). It is not to do with the key fobs, they all work fine and are connected correctly (I know this because the immobilising system activates and deactivates correctly remotely on all of them). ALL the door locks do not respond either by the locking switches on the drivers door or by the key fobs. The indicators do flash however and a relay is clicking somewhere under the dash. I have double checked all fuses both in the cab and in the engine compartment and they are all ok.

Does anyone have any suggestions as to the issue, could there be an issue with the BCM?

Many thanks!

 

[Lightrofit]

Are your keys genuine VW OEM keys? How many do you have?

If you sit in the van with the doors closed, does the unlock button on the inside drivers door trigger the locks?

Does the key work in the drivers door manual lock on the outside handle?

FYI, the immobiliser system and door locks are not part of the same system.

 

[Deleted member 11283]

Hi thanks for replying!
1. Yes they are oem keys.
2. No, the unlock/lock buttons do not activate the mechanisms but the lights and red leds flash.
3. The manual key works in the drivers door but only turns that door’s mechanism.
4. The immobiliser system is functioning fine, it’s the central locking system that is at fault.

 

[Loz]

2. No, the unlock/lock buttons do not activate the mechanisms but the lights and red leds flash.

not the fob, the button on the door card by the mirror switch?

 

[Deleted member 11283]

those are the buttons I’m talking about, not the fob!

 

[Loz]

Are the doors showing as closed on the display? Do they all show open and closed.

 

[Deleted member 11283]

All doors are shown as fully shut on the display. As I originally stated this error only occurred after battery disconnect, all sensors were not disturbed in any way. Electrically and electronically everything is functioning correctly bar the central lock mechanism.

 

[Loz]

Are the one touch windows working?

 

[Loz]

those are the buttons I’m talking about, not the fob!

Yet in your answer 2. you said the lights flash when you press the door buttons? The lights don't usually flash when pressing the door card buttons?? please clarify.

 

[Lightrofit]

Hi thanks for replying!
1. Yes they are oem keys.
2. No, the unlock/lock buttons do not activate the mechanisms but the lights and red leds flash.
3. The manual key works in the drivers door but only turns that door’s mechanism.
4. The immobiliser system is functioning fine, it’s the central locking system that is at fault.

Ok:

There should be no flashing when the door button by the mirror switch is operated so that’s strange.

When I get a sec, I’ll check for any fuses but both doors communicate with the BCM for central locking auth and trigger.

Have you scanned the van for stored fault codes?

It shouldn’t have but with everything else working it could be worth checking that the BCM hasn’t magically set itself into transport mode as that would kill the central locking. Usually you can tell if this has happened as the interior lock button will still audibly trigger the unlock command but won’t trigger the lock command.

Lastly, is it a high mileage van? Could be worth casting an eye on the door hinge wiring, just in case it was failing and the battery disconnect pushed it over the edge.

 

[Wag86]

@jilesalcock did you get this sorted. Just noticed mine doesn’t work.