Passat 3B: No Turn Signal When Locking/Unlocking

Hello everyone.

My girlfriend's car has been having a problem for a while where the turn signal doesn't work when locking or unlocking it with the remote.

I have the following errors saved:

01333 - Rear left door control unit (J388)
49-10 - No communication - Intermittent.
01131 - Control of turn signals.
25-10 - Undefined switch state - Intermittent.

What is likely meant by "undefined switch state"?

There's probably a microswitch in the lock that's broken.
This refers to an undefined state.

Regards,
Maxx.

Thanks for the tip! Am I correct in understanding that all the locks are equipped with microswitches? If that's the case, how can I locate the defect? Unfortunately, I haven't found anything useful through searching...

Hello, yes, you can localize it by using a multimeter set to resistance measurement or continuity testing, and checking each microswitch one by one. Check it once when you press it and once when it's not pressed/activated. Then you'll see which one shows a change in value and which one doesn't.

Thank you for the reply! So, I need to remove the locks, or rather, the door panels and rear trim?

Before you completely disassemble everything, start by looking for the source of your problems where they are most frequent. How about the rear left door? It seems you have a VAG COM device; use it. You can check the status of all the doors: opening, closing, locking, and pay close attention to the readings on your laptop.

Another important thing to check are the cable conduits at the back of the doors.

Quote:

Thank you for the answer! So, I need to remove the locks, or rather, the door panels and rear trim?

Okay, I'll start by examining the supposedly defective lock.

For example, the front locks contain 5 microswitches.

1 Safe.
2 Unsaved.
3. Door open or closed (switch on the latch).
4 Unlock.
5. Conclusion.

Very often, cold solder joints on the ground plane of the circuit board are the cause.
The entry lights in the front doors are also controlled via this system.
If these (when the lamp is working correctly) do not function, it is an indication of cold solder joints. In rare cases, the microswitch (latch mechanism) may be the cause.
If the save function fails, a dislodged or broken save lever could also be the cause.

See here:
/viewtopic.php?t=14500&highlight=

Edit:

Oh, I just remembered that there have also been issues with a connection point "in the wiring harness" between the rear door and the comfort control unit.
You would have to really put the search function through its paces.