T6 tailgate on T5 tailgate van

thanks for your help @mmi

Still a couple problems occur, when I unlock the van with the key it unlocks the tailgate, and when try the handle nothing happens.

Before the handle would work with the ignition on, and the tailgate gate would open on lock/unlock by the key

Plus fault showing control circuit for unlocking rear lid, could be from a slightly bad pin to pin 23, and I’ve got a replacement for that now.

IMG_7306.jpeg

IMG_7305.jpeg
 
when I unlock the van with the key it unlocks the tailgate, and when try the handle nothing happens.
Not sure if I understand - unlocks the tailgate? How do you know it is unlocked? Is it T6 tailgate?

1710885283301.png
Hmmm.... this is not T6 BCM but T5.1. Need to check if the coding is the same.
 
Thanks @mmi, its a T5.1 conversion with a T6 tailgate ☺️. The lock is unlocking and leaves the tailgate door in its first unlocked stage partially open, but not fully. You can hear the tailgate door move slightly up, but to open it fully, i press unlock again on the key and open the tailgate.

Thanks you so much for your help and this why the T6 forum is great!!
 
The lock is unlocking and leaves the tailgate door in its first unlocked stage partially open, but not fully.
That's interesting - wouldn't expect the tailgate to "eject" when only unlocked - should be totally silent

Hmmm...it seems that the codings are not exactly the same on T5.1 and T6.
Below the codings of bytes 1, 2, 7 and 27 of a couple of T5.1.

I'm assuming green ones are tailgate (based on coding, byte 2, value 39 or 79 (opening switch also inside)).
Hopefully @WillWillWill can confirm his van below has barn doors?


1710964575019.png
The top 11 (above thick line) are exactly the same BCM - P version.​
Still can't see the coding to be wrong....​
The full BCM decoder in the downloads:​
 
Thank you again @mmi

Interestingly I have this fault code on control circuit for unlocking rear lid, could this be a bad earth or something

IMG_7310.jpeg
 
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Are you using your original wiring? I didn't have to code anything in when I did mine. I just adapted the plugs to suit and everything works as it should. Could you have a duff handle or a broken wire?
 
Ok, so.... and thanks everyone for your help. The van is now not unlocking when I press the key to unlock, if I run output tests on VCDs everything is ok and I can unlock the tailgate from here and if I bridge the two wires to the handle the lock opens, does this mean i have a defective rear tailgate handle mech, all faults are cleared and stay cleared. Is there another fuse i should check other than the central locking main fuse?
 
well still need to figure out the inside switch not sure what’s happened there,
Oops, missed that you have also switch inside - sorry :oops:
OEM switch would need the codings below to activate:
Byte 1 = B8 (hex)
Byte 2 = 79 (hex)
Try the following changes:
byte 1 from 2C to A8 (hex)​
byte 2 from A1 to 39 (hex)​
byte 7 from 31 to 11 (hex)​
byte 27 from 00 to 01 (hex)​
OR simply replace the full coding string with:
A8A839BA0A61341192284E106E6B9C55008071FF60860040320000010800​
 
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