Amiko Tsanava

I have dissembled the motor and assembled it back again just the correct way I guess. I've done it several times. Trying to use lubricants and other exploration.
Before placing the motor back on its place, I pluged the cables to the motor and let it rotate until it stopped in the open position and only then connected it back to its place.
So, I don't think that gear positions have to be corrected. They are cycling and they find their positions anyway, no matter how you put them back after reassembling the motor.

Am I correct?

By the way, the motor behaves the same way when it's not attached to the lid. When I push the CLOSING button in the lid, the motor rotates to the end position and goes back to the other end position again. I mean, the motor does the same thing regardless it's attached to the lid or removed.

ltooz_a6_a8_q7

There's a sensor with little gear. It can only rotate so many turns for the arc to swing, the electrical sensor must be correct.
Using the electrical to rotate and set the max/min is the problem

Amiko Tsanava

Do you mean this one?



How can I define the correct position for it?
I have removed and assembled this motor several times.
Are you sure the initial position of this sensor really matters when you put it back? It just rotates and counts the position of the gears I guess. So, the main thing is to locate those gears in OPEN LID possition before attaching the motor back to it's place.

dvs_dave

Seems like you have some sort of position sensor calibration error.

The motor should automatically calibrate itself when you plug it back in and will go from full open to closed and back to open. The position sensor is driven by a keyed shaft from the output shaft that only fits in one position in relation to the output shaft. So it’s not possible to have the two mechanically out of sync.

The position of rest of the drivetrain gears, clutch and motor are irrelevant and are not monitored.

Although as your trunk motor is already weak, as it needs a helping hand, save yourself a bunch of wasted time and effort and source the updated version with the metal body. If there’s anything you can take away from the numerous weak trunk motor threads and the various Rube Goldberg ways to fix it, is that none of them are reliable long term fixes, compared to installing the updated motor which is the only true long term solution.

ltooz_a6_a8_q7

I forgot to add the pictures on my page - https://www.dognmonkey.com/audi/how-...-audi-a8l.html




Use big screw driver that fits the gear


Rotate the gear clockwise until stop

When the gear stops, the position on the sensor should be as the first picture. Put it back, it should work. Your motor sounded very strong on Youtube.

Amiko Tsanava

thank you for that useful information.
I have just removed the motor AGAIN.
Here is the photo of it.




You can clearly see the position of the sensor.
Does it need any correction?
I think it's pretty close to the position on your photo.

I tried to turn the gear to the end position anyway and it went a little bit further and here's the result:



Now I'm going to put the motor back and see what happens.


*******

...and the result is the same.....

May be the gear on the lid mechanism side is damaged?
How can I remove the lid mechanism itself to take a look at it and see what's there?

********

So, I have removed the mechanism and here's the video of how it works without lid:


here are the photos of the connector from the mechanism-side:






It's teeth are arranged in such way that they can not be fitted to the motor any other way besides the way it should. It's hard to identify with eyes but I measured them and they are different sizes.

dvs_dave

As previously mentioned, it’s not physically possible to assemble the motor or mechanism so that the parts are out of synchronization with each other.

The output shaft position sensor on the motor can only be assembled one way in relation to the motor output shaft. And as you’ve found out, the motor can only be connected to the hinge mechanism one way.

There is some sort of electronic problem with the motor/position sensor that’s causing this fault. It’s a self calibrating system, so unless there is a way to recalibrate it using VCDS or do a deeper diagnosis with it (I don’t know of a way), its time for a new motor. Although I did notice on your video that the wiring to the motor doesn’t look factory. Has something been done with the wiring, as that could be where your problem lies.

And as previously mentioned, if you somehow manage to get your current one working again, it’s already become too weak to open the trunk lid so its still useless anyway. You’ll be fixing one problem, only to then be faced with the other well known problem.

Just buy yourself a replacement metal body motor and be done with it. Anything else is futile.

Amiko Tsanava

Yes I agree that the motor is weak. But I'm trying to find some way to repair it if it is possible and make it stronger or replace that particular part with stronger one.

Related to the position sensor, that's very weird. What can be wrong with it? I'm trying to figure out but without any results yet.

I'll try to solve this problem with current motor in a couple of days. If not, I'll buy a newer one that you mentioned with metal housing and more power.

Regarding those cables - yes they don't look like factory way, because one of those wires was damaged and I had to repair that wire and isolate the whole harness with my tape.

ltooz_a6_a8_q7

I had the same problem going halfway and reverse back before, it's the position sensor and full rotation setting before putting it back in. Keep fiddling with it you'll get it right.

Amiko Tsanava

But I did exactly what you told and it didn't work.
What else can I try?