Power-closing door problems

So understanding the voltage issue, I've done a further search on the forums and found this info on the California forum - There's definitely a change over relay that has lost power or something along those lines. Someone had a similar door issue, the door would only open when the engine was running, which would suggest increased voltage to the system / door opening motor. Any ideas of a relay that could be at fault...
 
It sounds like a high resistance path where you are getting a voltage drop.

All electric motors have a startup surge because when they are stationary they are a dead short electrically, it's only as they start moving that electrical energy is absorbed and changed into movement/kinetic energy. So the first burst of current can be between 3 to 8 times the running current.

So what does this mean for the wiring?

Well that motor still needs that fixed amount of energy to start, so it will always try and draw it.

Remember that for electrical energy power(watts) is current(amps) times voltage(volts)

So if you have voltage drop due to thinner than required cable, or cable with poor connections that adds resistance, then the only way a motor can get more energy from a falling voltage is drawn more current.

Now if left unchecked a jammed/stalled motor could continue trying to draw more current, generally with a battery/alternator/generator that will cause the voltage to drop further and more current drawn, a vicious cycle where the current will climb very high and start melting things - that's why all motor circuits are fused (and now you know why they are higher than you might expect) but also motor controllers generally measure the current drawn and if it's unusually high or the surge lasts too long power will be cut.

This is exactly the what the door module is doing and why you get that message.

There are two physical reasons why the motor can be drawing too much current and from a controller point of view they look the same:
  • There is more resistance/drag requiring more torque for the motor to start
  • There is more voltage drop in the electrical supply than designed for
 
If you are a T6 then this is the current flow diagram for the doors:


As @n10n noted earlier V293 is the door motor and J558 is to door control module - ideally finding a place to measure the voltage getting to those as close to them would give the best clues but I suspect in a moving door that might be hard.

So you'd need to trace the power for J558 - which looks like the 4mm feed in column 55 - then column 6 - then a variety of routes depending on model through fuse SH27 to SA3

On the diagram that looks like quite a high current direct route but worth checking it as carefully as you can and trying to see voltage levels under load with a multimeter. The T17j white coupling point might be a good place to check under the seat.

The only relays I can see near that route are because the supply also feeds charging/isolation relays in models with factory fitted second batteries.
 
Hi thanks for the info. My van is a T6.1. I looked for the 40amp fuse under the seat, but i think the T6.1 has the fuses in the fuse board under the dash. I can see x3 green 40amp fuses. Under the passengers seat, there were only a coupe of fuses, these were c10amps and below. I'll see what wires i can find to trace...
 
If you're a 6.1 then you should be the same as mine - you are looking for two 40A J type cube fuses on the edge by the door

20230711_093931.JPG
 
This morning, left door light started flashing, started up the van up, ran for 5 minutes, light went out when the voltage in the battery picked up. This afternoon I’ve checked the Van Battery which is at 12.8v, at the two 40amps fuses, 12.8v. No fuse, left door stops working, fuse back in, door works fine. 12.8v at the input to the main control box at rear. Control boxes switched over, so it’s not the control box. Sliding door - Door open / Door close 12.8v on the white & white brown wires to the motor. I now find it hard to believe the voltage is dropping in the main power wire, therefore the wire must be good. All of the wires under the front seat are perfect condition. Where is the Gemlin that requires high volts for the door to work…
 
I’ve checked the earth wires, they seem ok, clean and get 12.8v volts on the live when using the earth wire or earthing the multi meter to the body. Door is currently working fine. I’ll keep a check on the battery and do more digging if/when the light returns. Thanks for the help
 
@T6 - G how did you access the drivers side main control module? I have the rear space heater which is where I expected it to be. Mine has been working OK until u used my heated front screen this morning and now it's gone haywire again.
 
@T6 - G how did you access the drivers side main control module? I have the rear space heater which is where I expected it to be. Mine has been working OK until u used my heated front screen this morning and now it's gone haywire again.
Right side rear, behind the panel by the rear wheel arch / light cluster. Same position as the left hand side.
 
Right side rear, behind the panel by the rear wheel arch / light cluster. Same position as the left hand side.
Ah I think it is either different or impossible to get to with the rear heater installed! How is your door behaving?
 
Ah I think it is either different or impossible to get to with the rear heater installed! How is your door behaving?
Door is still very temperamental, the level of battery charge is definitely the issue that makes the door work or stop working.
What I need to do to find out what part requires that level of charge is now beyond me. I’ve ran out of things I can check..
 
My t6.1 has a similar problem, but with offside door. Swapped everything from side to side. Is outer handle doesn’t open door, inner does- opens very abruptly- not “soft” opening like normally. Soft close works if I get door into position for it to operate- I’ve got 12.2 v at motors & fueses below nsf seat. Battery is showing 11.95 on multi meter. Just stuck on charge- most uses have Been 2 miles or less the last few months, and battery is original
 
My t6.1 has a similar problem, but with offside door. Swapped everything from side to side. Is outer handle doesn’t open door, inner does- opens very abruptly- not “soft” opening like normally. Soft close works if I get door into position for it to operate- I’ve got 12.2 v at motors & fueses below nsf seat. Battery is showing 11.95 on multi meter. Just stuck on charge- most uses have Been 2 miles or less the last few months, and battery is original
I’d be interested if the battery charge solves the problem - I know when the start / stop function works, the door should also work
 
Charged battery sitting at 12.7- no change, fault still the same.
There are a pair of wires to a micro switch on the outer door handle from the “soft closing” unit(?) one has no continuity, pipes another cable in but still no joy
 
Long shot, but I don't suppose anyone ever made any progress with this? I've just had my T6.1 converted and I'm now getting this exact issue with one of the sliding doors. If I hold the button while turning on ignition it'll open a few inches then stops, VCDS says motor over current.

Has been working throughout the conversion then suddenly started happening one day. Van is kept charged always, happens if the engine is running or not. Van isn't even a year old so I'd be surprised if there are rusted rollers or anything.

Just thought I'd check before ripping everything back out...
 
Hi, I still have the issue. If you get further than me with fault finding, please provide updates.
 
Hi all, just thought I'd provide my situation and solution in case it helps anyone who finds this thread in the future.

Vehicle: 2023 T6.1 with two power doors - suddenly from nowhere, driver's side sliding door would not open nor shut on the switch. VCDS showed pinch sensor was to blame, but I tested it with a meter and it wasn't the issue. (Note as well that VCDS actually reported it was the wrong door that was causing the issue so make sure you read both sides - VW confirmed this can happen in VCDS, something to do with RHD vs LHD vehicles)

The door could be "fooled" into opening by holding the dash button while turning the ignition on, this presumably worked because it was sending the "open the door" signal before it was reading the status of the pinch sensor. The inside handle would open the door sometimes, other times it wouldn't. All wiring checked, could not find anything, so returned it to VW as it was under warranty.

The issue ended up being the receiver unit in the back of the van, where there are two units above the wheel well - I think the receiver is the smaller of the two units, the larger is the motor controller which clearly worked fine.

I believe how it works is that inside the door there's a wireless sender unit (which presumably charges its battery when the door is shut) which sends the pinch sensor signal to the receiver which is over by the motor controller. The receiver had failed, so that signal wasn't getting through and so the van thought the pinch sensor was activated.

Receiver was replaced immediately from UK stock and the door has (touch wood) worked ever since.

Hope that helps somebody.
 
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