Stellmotor Heckklappe durchmessen

[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