Passat 3B, FFB+ Fensterheber+Interior lighting without function

Hello dear diesel engine enthusiasts, who can help us (me and a colleague):

It concerns a Passat, manufactured in 1999 (3B), with engine code AFN.

Neither the window controls, nor the remote control, nor the interior lights are working.
The door/unlock function with the furthest button on the driver's door still works.

It all started with spor. Problems that FFB only worked on the second or third attempt (we were still thinking about the battery in the key).
Then the same problems occurred with the window lifts, and eventually, everything stopped working.
I can't say exactly when the interior lighting stopped working.

All fuses have been checked, at various locations. Cables and connectors were checked (e.g., in the driver's door, in the A-pillar below the footwell, at the engine control unit, and with VAG-COM, error codes were read out).
It has been noticed that the comfort control unit (address 46) cannot be accessed.
All other control units are OK and without any error codes.

The STGR list from better times (2005), when everything was working:
----------------------------------------------------------------------
Chassis Type: 3B - B5 VW Passat 97>Scan: 01,02,03,08,15,16,17,19,35,36,37,46,55,56,57,58,76

Address 01 -------------------------------------------------------
Controller: 038 906 018 P
Component: 1.9l R4 EDC 00SG 1629
Coding: 00002
Shop #: WSC 05311
No fault code found.

Address 03 -------------------------------------------------------
Controller: 8E0 614 111 AB
Component: ABS 5.3 FRONT D00
Coding: 0273004281
Shop #: BB 24548
No fault code found.

Address 08 -------------------------------------------------------
Controller: 3B1 907 044 B
Component: CLIMATRONIC V 1.0.0
Coding: 05000
Shop #: WSC 05311
No fault code found.

Skipping Address 15-Airbags

Address 17 -------------------------------------------------------
Controller: 3B1 919 880 C
Component: B5-COMBINATION INSTRUMENT VDO V01
Coding: 04140
Shop #: WSC 00111
IMMO-IDENTNR: VWZ7Z0W1174516
No fault code found.

Address 46 -------------------------------------------------------
Controller: 1J0 959 799 AH
Component: 33 Central-SG Cooker 0001
Coding: 04097
Shop #: WSC 05311
No fault code found.

End -------------------------------------------------------

If you repeat the query now, the address 46 is simply missing!

Also, even replacing the comfort STGR 46 with a trial unit didn't make any difference (battery disconnected, comfort-STGR removed, used one with the same part number (1J0959799AH) installed (two different ones), battery reconnected).
Or must the new one be "authorized" first in order to be seen with VAG-COM?

On the STGR 46, there are also various... Measure voltages and also measure +12V on a pin.
However, since I don't have the pinout of the STGR, I can't say whether the values are okay.

Who has tips on what the possible causes could be, such as the wiring harness, the SUB-STGR in a door, the motor-STGR, etc.?

Could the STGR 46 be checked outside the vehicle (using only a VAG-COM, a +12V source, and a few connections in between), or does the communication run through the engine's STGR?

While it's not my car, I'd like to help my colleague.

Thank you for your responses.

Peter

Hello, have you ever checked the wiring to the central control unit? They are located in a wiring harness directly on the chassis and are often corroded by moisture. So, simply unwrap the wiring harness 40cm, and the connectors will either be wrapped with thicker tape or have a type of shrink fitting. If there is anything green underneath, you have already found the fault! This sounds like the control unit is missing a power supply. I have also had this problem myself twice. Cut out the original connectors and properly solder the wires together, and then put a proper shrink sleeve over them, and you will no longer have any problems. Best regards, Carsten

Hello Carsten,

Bullseye

We checked this on Friday, and out of the five cable connectors, two were completely faulty. By unwinding the insulation and exposing the connectors, we were able to separate the two. The remaining three are still okay.

The connectors were so well "hidden" in the cable harness, we would never have found them without your tip.

After renewing both connectors, everything is working perfectly again

Unfortunately, I couldn't reply earlier because I only have internet access/email in the office.

Thank you again for the super help.

Greetings, Peter

I have a similar problem with a Golf IV, 2002 model, where the power steering and window motors are not working.

If the window regulators are not working, I also cannot access the 46th control unit. If I then disconnect and reconnect the connectors from the central control unit, the window regulators will work again. I can also access the control unit with VAG-COM, but the FFB (front/rear blind function) does not work.
The window mechanisms then work again for a while, and then the same problem occurs again.
If the window switches are working, I can unplug the connectors from the central control unit again, and surprisingly, the window switches still work.

Should the window motors still function without the central control unit? I haven't found any connection between the control units on the wiring diagram, except for the CAN lines. I measured this with the oscilloscope, and I observed a signal on both lines.

I have checked the power supply and ground supply at the connector, and they are OK, however, this was without the control unit being connected. It is also not a defect entry.

LED on FFB illuminates when a button is pressed, but it is not displayed in the measurement blocks.

Does the cable harness also lie under the carpet in the Golf IV, and could I have the same problem as described above, or is this only a problem with the Passat?


Thank you.

Chris

Hello!!!

I'm having almost the same problem, but my original alarm system is also acting up and keeps going off (even at night). The KSG (central locking system) no longer responds to the command to turn off the alarm by activating it twice, so it can't be turned off. I had the hood contact switch replaced at the dealership, as it was constantly flashing/dimming, but that didn't fix the problem. Could it be the KSG?

Best regards, Enrico