Central Control Unit Upgrade for Comfort Systems (J393)

A brief question regarding the installation/expansion of the central control unit for comfort systems (J393):

Since I always read repair manuals before working on anything, the following sentence from VW confused me:

Quote:

Turn off the ignition and all electrical consumers, and lock the ignition key or starter button in position 0 (off).

So it seems the battery doesn't need to be disconnected. And I assume that the control unit will not lose its coding and settings (so I don't have to note anything down beforehand).

Aber was soll ich da Besonderes mit dem Zündschlüssel veranstalten? Uand why?

I should have just turned off the ignition and removed the key.

What is special about "position 0", and why is it required here?

Or is this just a "misunderstanding" on my part, and simply removing the ignition key is perfectly sufficient (and "position 0" is equivalent to that, meaning "removed, but still parked in the holder"...)?

While this is probably being overly precise, having written technical manuals myself, I tend to notice these kinds of things (here's the following text from the VW repair manual):

Quote:

Turn off the ignition and all electrical consumers, and lock the ignition key or starter button in position 0 (off).

I now have a clearer understanding of where my confusion stems from:

According to the owner's manual, the ignition switch in my vehicle has three positions, numbered as follows (and no "position 0"):

- 1: Ignition off, steering lock engaged.
- 2: Turn on the ignition or preheating.
- 3: Start the engine and drive

. Regarding point 3: "Once the engine starts, the ignition key remains in this position." If someone had asked me, I would have probably said that when driving, the ignition key is in the "ignition on" position:-).

After the engine is switched off, the key automatically returns to position 1. The key fob can then be removed.

Whether something is already (or still) turned on in position 1 is something I still don't quite understand, but I can live with that. (Probably, for example, the radio will remain on until the key is completely removed.)

It's completely unclear to me why the key is supposed to remain in this position during the expansion of the central control unit for comfort systems (J393), especially since, as mentioned, there is no "0" position.

I will, as usual, completely remove the ignition key while working on it.

Position 0 comes from the old "Zünschlüsseln" (a type of key) for turning.
Pos 1 = Turn on the radio.
2 = Turn on the ignition.
3 = Starter motor
0 = completely off.

"Ignition off" probably refers to that, even though the German is interesting...

Disconnecting the battery won't hurt anything, but it's not a necessity.

Quote:

VW Repair Manual: "... engage the ignition key or starter button in position 0 (off)"

Quote:

Guste: "Position 0" comes from the old ignition keys used for turning

.
Logically speaking, that might be the case. However, since I am certain that VW did not simply use sloppy wording in the repair manual that corresponds to the vehicle, I have looked into it more closely:

- The (yellow) warning light for steering assistance briefly illuminates when the ignition key is inserted in position "1" (and then turns off again), not only in position 2, "ignition on".

- At the same time, the radio will turn on (if it was on when the key was removed).

- When you remove the key from this position "1", the radio turns off, and (if the engine has been turned off), the interior lights turn on.

So far, so good (and well-known).

My original objection was:

Quote:

There is no position labeled "Position 0 (Inventory)" (and the user manual does not mention it anywhere).

But what's amazing is:

The "0" position actually exists in my vehicle as well (Passat Variant B6 (3C5), 2006).

When removing the ignition key from position "1" (and you can hear a relay sound), it is not immediately released, but rather, before the actual release, there is first another "park position" of the key, which is defined by spring tension.

This will be the "Position 0 (Supplies)" referred to in the repair manual.

Why, and this was my original question, must the ignition key be placed in the "position 0" when removing the comfort control unit? (This position corresponds to the state of "ignition key removed").

My answer:

According to the repair manual, the vehicle does not need to be de-energized when removing the comfort control unit (disconnecting the battery is not required, which is usually strictly enforced and clearly noted). Therefore, the key should be in a position where the buttons on the remote locking system cannot be pressed. (Without the comfort control unit, the vehicle's locking system will not function, so conversely, operating the remote key would send signal voltages to the lines leading to the comfort control unit.)

As I mentioned at the beginning: none of it is very important. (But I always like to understand what I'm reading, and if it doesn't make much sense, I'll make a note of it first.)

For me, the puzzle is now sufficiently solved.