Stellmotor Heckklappe durchmessen

[Tux]

Hello Audiot

First of all: Very well documented and good initiative !

From what I've read so far I deduce that boot lock motor V53 is O.K. but you have a problem/shortage in the wiring.

The reason beeing that always both signals (locked/unlocked) are on or off at the same time. This can be caused by a shortage or a loose (floating) ground connection !

The wiring error is located somewhere between motor V53 and control unit J256.

Pin 1,2,6 (belonging to the micro switches) of the boot lock motor connect to a green 3-fold connector in the lid.
The signal of Pin 6 is then conducted by a brown 1,0 sqm cable to another red 2-fold connector in the trunk lid. This connects to 0,5 sqm ground connection in the boot loom.
The 2 signals of Pin 1+2 end in a green 6-fold connector in the boot itself, right side.

Now several measurements have to be taken

• Green an red connector in boot lid securely plugged
  
• Is Pin 6 of the V53 plug really connected to ground with low Ohm's ?
  
• Is a shortage between Pins 1+2 of V53 plug measurable, when green 6-fold connector in the boot is unplugged ?
  
• Is a shortage between Pins B13+B14 of J256 plug measurable, when green 6-fold connector in the boot is unplugged ?
  

Remember, that with a faulty boot loom measurements can vary between open and closed state. But you said that you replaced the loom already. (With what ? Both sides ?)

Best of luck
Tux

[lemmy]

Hi Ed,

the symptoms of your problem are looking quite similar to those I had (click me) several years ago. I also read that your car is of the same age as mine.

I hope it's not true, but I really am afraid that the only solution will be the changing of your controller (this is what Yahoo's Babel Fish calls the "Steuergerät") for the roof.

Good luck!

[audiot]

Hi, thanks and yes, thats what Im worried about as well.. Even more so when I manually did the switch at the controller, to pin b13 and b14, and still got the same faulty results.
If anyone has a spare controller for sale I would love to hear.
Thanks!

[audiot]

Hi Tux, apologies, I only just now saw your answer. Thanks for your your reply!!
I indeed did the measurings between the green boot lock motor plug, but didnt have any different result.
In what I thought would be the 'defining' test, I unplugged the plug in which the right boot loom ends. So as to count out any potential malfunction of broken wires in the boot loom.
Then I took the B plug on the roof controller/j256 apart and took out the wires on pin b13 and b14 out of the plug.
Then I plugged it back into the j256 and put the ground (originating from the brown 1 sq m) first to b13 and then to b14. That gave me exactly the same faulty readings; xxxx00xx, and xxxx11xx.
That must mean the roof controller/j256 is faulty, isn't it?
Many thanks!

[Tux]

Hi audiot

The last thing that came into my mind was a possible fault in the wiring between J256 and the boot. The location is depicted in a FAQ entry.

But since you put a defined signal to pin b13 and b14 while the controller is still malfunctioning, I am afraid you have to hunt for a used J256 out there. I.E. Lemmy was right.

Tux

[audiot]

Hi Tux,

Thanks - yes I'm afraid so.
One thing I would like to check, is to do the Block readings from the j256 without the B plug attached, to see if any other lines in the B plug are playing a role in the problem. (in my previous reading as mentioned above I only disconnected b13 and b14 from the plug). However, when I unplug the B plug, VAG COM looses connection to J256 - apparently because J256 looses power.

Do you know the pinout of the J256, so I can try and connect only the power lines, and simulate b13->GND and b14->GND - and that way omit the rest of the pins/cables?

Also - I presume its unlikely, but is there a way to test anything on the J256, disconnected?

Thanks!

[audiot]

Tux,
I've did all the tests again just now, and it still feels weird that most other bits react perfectly well - handbrake, central console roof switch, roof latch etc. - all going from 0 to 1 and back where and when they need to.

From your experience, is it still likely that the J256 is broken, if only one bit (V53) is wrongly measured from the whole sequence?
I don't know, but it feels that if the J256 would be faulty, more would go wrong than just and always one and the same bit (the boot lock motor v53) - or not? (as indicated in my earlier mentioned diagram, image: http://img97.imageshack.us/img97/1029/bo...roblem.jpg )

By the way, with the green 6-fold connector in the boot unplugged (as well as all connectors unplugged), I get bit 5 and bit 6 both value 0. Shouldnt that be 1 and 0?

Also, how serious can I take the VAG COM fault readings? They seem rather random, and some come and go, but
01111 - Luggage Comp. Lock Actuator Motor 1
28-10 - Short to B+ - Intermittent
seems persistent.

[audiot]

edit: sorry, just now I found some more on the pinouts here
but still curious if anyone has any ideas on if its possible to test J256 / Steuergerät on itself / unplugged

[Tux]

Hi there Audiot

Wann ich mitt der Stellmotor nicht angeschlossen, in der plug (die normalerweise in der Stellmotor sitzt) 6 und 1 mit einander verbinde, dan gibt VAG COM Gruppe 1, Block 1: 10110011. Wann ich 6 und 2 mit einander verbinde, dan gibt es 10111111
Wann nichts verbunden ist, gibts wieder 10110011.
-------zzzzzzziiiiipppppp-------------
By the way, with the green 6-fold connector in the boot unplugged (as well as all connectors unplugged), I get bit 5 and bit 6 both value 0. Shouldnt that be 1 and 0?

A zero (0) reading is OK in this case, since it indicates an open switch. All switches close the loop towards ground potential.
A reading of one (1) indicates the the specified switch has made contact from sensor pin on J256 to ground. The switch has pulled the 12V+ potential to 0V Ground.
Only that these two readings should have an XOR behaviour. (From engineering point of view this is a waste of hardware and connections. One signal say it all) Therefore both open/unconnected pins at the same time on the controller J256 is a "shortage to B+". One line carries the signal of the other.

Then I took the B plug on the roof controller/j256 apart and took out the wires on pin b13 and b14 out of the plug. Then I plugged it back into the j256 and put the ground (originating from the brown 1 sq m) first to b13 and then to b14. That gave me exactly the same faulty readings; xxxx00xx, and xxxx11xx.

You measured it yourself. Seeing is believing. A ground connection on one input is immediately detected on the other one too. B13+14 are coupled by an error in the circuit.

From your experience, is it still likely that the J256 is broken, if only one bit (V53) is wrongly measured from the whole sequence?

Yes ! It is still likely that the controller is broken. Even though only 2 sensor inputs are concerned, this corrupts the whole sequence.
I dare not say if the sensor circuitry may be repaired. No one I know of has tried yet. No one has the circuit diagram.

Other intermittent error can originate form a disrupted open/close sequence.

Best regards
Tux

[Grappa]

Hi there,

I was reading this thread since some time now. As TUX and lemmy were already feeding in all the information I could provide to you, I did not write redundant posts...

But, to this point I can at least deliver some insights:

...
I dare not say if the sensor circuitry may be repaired. No one I know of has tried yet. No one has the circuit diagram.
...

I have got currently the broken CU from lemmys car. He gave it to me after he had resolved his issue with his roof by replacing his unit.
My intention was to open it and check it for errors that could be detected visually. Result: nothing...

But I took some pictures that show the comlexity of the circuit board. I doubt that someone (like me) without specific knowledge may be able to repair something in the unit at all.
The pictures can be found in this posting. Just klick on the links in posting #54, they forward you to high definition pictures...