Graphics Card Failure After 8 Weeks? Troubleshooting.

My brother has a 1999 Passat Variant with an AFN engine. I replaced his steering column switch with one that has the GRA function and bought the corresponding wiring harness on eBay.
Alles verkabelt, Steuergerät freigeschaltet mit der 11463, alles ok. Test drive available.

Now he uses the cruise control every day on the highway, and suddenly, it stopped working. No matter what speed you're going, pressing the 'SET' button does nothing.

Okay, I've searched through the measurement data blocks and found group 006, which displays the switch positions. I'm now toggling the steering column switch back and forth and recording what happens each time. This is the actual state in the vehicle. I can't find anywhere to see the desired state; could someone please verify that everything seems okay?

For further information: The speed signal on position 1 in the instrument cluster (MWB 6) normally increases and decreases while driving, so the V-signal is present and functioning correctly. Another test in the climate control system on channel 16 also shows a perfect V-signal! Although an aftermarket radio is installed, I already disconnected the GALA signal from the connector about 1.5 years ago.

The clutch pedal switch and the brake pedal switch are also shown here in group 6. I was able to see and verify the values again in group 21, and they are also correct!



Group 006:

All done.

0 km/h
0 0 0
0 0 0 0 0 0
0


Cruise control on.

0 km/h
0 0 0
0 0 0 0 0 1
1.



Press the 'SET' button.

0 km/h
0 0 0
0 0 0 1 0 1
1.



Slide the switch to 'RES'.

0 km/h
0 0 0
0 0 1 0 0 1
1.



Cruise control activated and brake pedal pressed.

0 km/h
0 1 1
0 1 0 0 0 1
1.



Cruise control activated and clutch depressed.

0 km/h
1 0 0
1 0 0 0 0 1
1.




As far as I can tell, all the prerequisites for the cruise control function are met, but it simply doesn't work anymore. For the past eight weeks, it was functioning perfectly.

Check the connector located at the bottom of the footwell (or under the control unit). During my modification, I had pushed a pin out of this connector, and sometimes it worked, other times not.

I'll do that right away, but shouldn't that also be visible in the data logging section? Also, even while driving, the values cleanly switch from 0 to 1 when the switch is activated...?

Steering column lever is broken/defective...

I'm experiencing a similar problem with my A3, manufactured in 2002.
Er geht eigendlich nur wenn es kalt ist. Im MWB66 werden aber immer alle Tasten beim drücken korrekt angezeigt. An was kann es liegen? Steering column lever?
The clutch switch and brake light switch are new.

Hi Rainer, how do you know that? Is it the measurement display? Or something else? The steering shaft lever is only 8 weeks old...

It's a guess, but apparently it's unfortunately a fairly common cause. It's also worth observing the device for a longer period of time (to check for intermittent issues with the switch).

Here are the details about the bits:

Quote:

1xx - Brake light switch (F) closed. ; x1x - Brake pedal switch (F47) open. ; xx1 - Clutch pedal switch (F36) is open

.
0 1 1

Quote:

; 1xxxxx - Clutch pedal depressed. ; x1xxxx - Brake pedal pressed. ; xx1xxx - Resume/Accelerate ; xxx1xx - Speed delay ; xxxx1x - GRA with memory ; xxxxx1 - GRA enabled

0 1 0 0 0 1 1

Just wanted to give you an update – it was actually the steering column lever! Even though all the measurements from the diagnostic tool indicated everything was okay.

Great, thanks for the feedback.

The problem is located at the flat ribbon cable connector on the steering column lever.
The circuit board traces are rubbing against each other at one corner when the light flashes, which is causing the contact to break.
Can you also repair it with silver conductive paint if you're skilled?
Then you need to be careful during installation to make sure the cable doesn't get pinched again.

"I also experienced this with my AJM, and I noticed it during the disassembly."