Barn-door To Tailgate Conversion
- Thread starter Ads_Essex
- Start date
I am not sure how this would be possible or for me to check. As I mentioned I did goto the trouble of running the 2 wires all the way back to the bcm. I am pretty sure the switch in the tailgate the soft close switch is just shorted to ground in order to send the message to the bcm.
But the issue will be somthing like you suggested. So if you know anyway I can check this I will
I mean any fault codes now after a couple of lock/unlocks, playing with tailgate handle at different tailgate positions, etc.
Correct - that's why I'm thinking when the door contact switch opens (=door closed-closed) the BCM can't see the handle switch anymore.
Just the same fault as before now after a while of testing. As nothings really changed to as I had it before.
You must be right about this central locking and the switch having issues. But I don’t understand what would be causing it nor what to do in order to cure the problem. If you have anymore suggestions I will keep trying.
You must be right about this central locking and the switch having issues. But I don’t understand what would be causing it nor what to do in order to cure the problem. If you have anymore suggestions I will keep trying.
So, the tailgate handle switch was obviously a new wire - connecting into BCM pin 23 (black connector).
Can you tap on that wire and simply short it to ground - and verify with VCDS measurement group 008-4 that BCM recognises it (the red box showing as "Active"), also in tailgate position closed-closed. If still not seen in 008-4 perhaps need cut the wire (to isolate tailgate wiring completely) and short to ground just the BCM end of the wire.
If still struggling please measure voltage (against chassis ground) on that wire in different tailgate positions - both handle switch not pressed and pressed.
Earthing the wire (close to BCM without tailgate wiring involved) is just to verify that the BCM registers it correctly as "Active" in 008-4 even when tailgate is in position closed-closed.
The would prove there is a wiring issue inside/close tailgate. The earthing is not meant to be a permanent solution, only a measurement.
Ok so I did some further testing. I will try to describe what I did. I did also make a video to show the behaviour of the locks whilst carrying out the test.
So what did I do
I connect to the the wire which goes to the tailgate handle soft switch. The switch we’ve been talking about that just needs to go to ground to activate. I had a good length of wire so was able to earth it on the chassis near the sliding door away from earth point it uses at moment.
What to point out
What I should point out at this point is the earth is the same which is used in the tailgate catch which registers if the tailgate is closed and open.
So open closed status
Now when I carried out the test I got slightly different results. Firstly though earth the wire would still show in group 008 box 1 either open or closed as it still triggers the central locking for some reason every time. So I still have to do the same thing , which is unlock the van with remote and then quickly try to open the tailgate. It will then power the actuator to release the tailgate. Group 008 box 4 show active as I ground the wire. So same results as before.
So now closed closed status
Now this is where I now also get a reading which I don’t get when using the earth in the tailgate. Using the earth on near the sliding door. It now does register the button press of the handle and shows active when pressed or in this case when I earth the cable. This has never happened before and when I test agin with earth in the tailgate it doesn’t register the button press with status closed closed. Unfortunately what it still doesn’t do is power the actuator to open the tailgate.
But this is a significant step forward
- obviously need to get button to register also with earth in the tailgate. Missing earth or wiring issue?Did you bring a dedicated wire through the bellows for tailgate earthing?
Another or the same wiring issue as above???
Yes it seems that with earthing the tailgate switch it will register the button press even when closed closed status in the messing blocks. But that still doesn’t explain why it still won’t open the tailgate even when it knows the correct status ie closed closed.But this is a significant step forward
Did you bring a dedicated wire through the bellows for tailgate earthing?
Another or the same wiring issue as above???
So yes I took the correct esparto for the tailgate and also checked with multi meter that I had continuity with the earth going to the tailgate and the chassis. Also other things in the tailgate are happy to use the earth.
So I am not sure what else to do. If I go to the trouble of running another earth to the tailgate for example it still wouldn’t act correctly and make no actual difference unless there’s something I can change in the vcds?
Also I still have no idea why it keeps activating the central locking when the handle is pressed. Surely this isn’t normal?
Just thinking that something dislodges at closed-closed because the solenoid definitely should pull then.
Well, perhaps you could try the following - keeping tailgate open and manually operating the tailgate latch.
Ignition off, no keys in the barrel.
By using VCDS set up monitoring of BCM groups 006 and 008.
Leave the tailgate open and "simulate" door switch open/closed by operating manually the latch mechanism in the tailgate.
Verify by VCDS open-open and the handle button are registered
Verify no solenoid pull (as tailgate is open-open)
Push the latch tongue with screwdriver ONE click inwards
Verify open-closed and then press&hold the handle button - verify the button registered
Verify the solenoid pulls and doors return back to open-open
THEN
Push the tongue with screwdriver TWO clicks inwards
Verify CLOSED-CLOSED, and now press&hold the handle button
Verify by VCDS the button is registered
How about solenoid now???
If no solenoid action please set VCDS to monitor ONLY group 011 It's IMPORTANT to have only one group monitor to have high enough sampling rate to catch solenoid activation pulse seen in group 011-1.
Repeat the closed-closed and press the handle button.
A short flash of "OK" in 011-1 ???
No, not normal.
Desperate times. It seems that you have swapped the door switches in the wiring. Actually BCM expects to see them as as Closed-Open
Anyways, don't know if that's a significant thing.
Ok so I had time to give everything a go again and take note of my findings. Doing as you asked to test.
Whether it’s relevant or not it needs pointing out. But first I will outline the conditions of the tests.
So I again ran a long wire from the tailgate switch handle which will only require an earth to close the switch. Ie get signal.
I am earthing this wire for testing on the passenger door hook. So I can see the laptop readings.
The tailgate catch has 3 wires 1 is earth and 2 others are signal wires. Depending on the state of the catch it close either one or both of the signal wires to earth. For this exercise I have used jumper wires with pins and a connector block so I can test each phase.
Now below are the results of each state. But for some reason somthing else happened. Whilst in started carrying out the tests. It just stopped but not immediately triggered the door locks as I earth the wire for the tailgate switch. Then as I continued with the tests it seemed to act correctly not triggering the central locking. It has since be ok and remained the same. Ie now when I unlock the van and wait some time before opening the tailgate this doesn’t trigger the central locking and just operates as it should !
Unfortunately a week later and after a long drive to and back from northwales. It has reverted back to the same behaviour. Ie trying to lock or unlock the doors when you press the tailgate switch. But this is still using the earth in the tailgate which could be the issue I don’t know
However as you can see from the results. The bcm for some reason will not trigger the actuator in the closed closed status and therefore keep throwing up faults.
So it is still open closed status that it shows the correct behaviour.
Open open status
Seems to behave it’s
Self.
The door locks don’t get activated so locks don’t either open or close.
Group 008 block 4 shows active when i earth the wire. but I don’t hear the relay in the cockpit drivers side it doesn’t activate the Solenoid.
Group 11 block 1 doesn’t register anything when doors are unlocked
Closed closed
Again seems to now not be activating the locks. Registering the button press when wire is earthed and this time I can hear the relay in the cockpit activating. But still nothing from the actuator
If I locks the doors via remote. Then earth the wire there’s no sound from the relay in the cockpit but I will get a reading in group 008 block 4 saying activated
Group 11 gets Not ok in block 1 when doors are unlocked
Open closed
Again seems to now not be activating the locks . When I lock the van I still see activated in group 008 block 4 but nothing from the relay in the cockpit. When I unlock the doors via remote. When I earth the wire it powers the actuator and acts like it should
Group 11 gets ok in block 1 when doors are unlocked
Closed open
Again seems to now not be activating the locks . When I lock the van I still see activated in group 008 block 4 but nothing from the relay in the cockpit. When I unlock the doors via remote. When I earth the wire it doesn’t power the relay.
Group 11 gets Not ok in block 1 when doors are unlocked
I think it would have been better to have tailgate up/open and just operate the latch with a screwdriver - to see how the actual microswitches register.
Correct - the solenoid does not activate normally when open-open.
What does group 011-1 actually show - as mentioned doesn't register anything?
What does group 011-1 show "normally" - thus when not flashing "the "ok"???
At this phase does the group 011-1 show permanently "not ok", or only when the switch is earthed? What does group 011-1 show "normally"
A good piece of information!
011-1 is the solenoid activation status - and obviously the "open circuit" is seen as status "not ok" at the solenoid feed
To me it looks like there might actually be two issues
(1) earthing issue in the tailgate when "closed-closed"
(2) wiring problem only when closed-closed
Possibly the solenoid is fed accidentally via a door position switch - because only "closed-closed" creates the open circuit.Or possibly (1) and (2) are just a single issue
Possibly somehow accidental wiring via door position switch is the root cause - as when closed-closed(a) handle switch is not registered, and
(b) solenoid doesn't get electric feed - status "not ok" - also fault "Open circuit" appears
It seems like a rabbit hole. I tend to agree with you. I really don’t understand why it is so and won’t work after taking the time to run the 2 wires from the bcm to tailgate. Why it would then on the computer not function as it should at all. For example the closed closed this is where it should be unlocking of course but it has always refused to do it from this status.
Also to me changing earths may or may not be the issue. I am next going to try
Instead of using the earth that’s currently being used in the tailgate for the latch giving the status of the tailgate open, closed etc. I will also run a new earth to the body and test that to see if anything else changes
Sorry to jump in! I know for struts you need T5 ones. I have these and the height is now perfect. Only thing is they are hard to shut! Feels like I’m doing lat push downs at the gym to shut. How is everyone else’s feel? They aren’t the uprated ones, they’re like 900 odd Nm ones
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