vajper

Hi there, first post here!

Got myself an 2005 A8 a couple of days ago. Maybe not the smartest car choice but oh, so much fun :-) Now I'm working my way through all the problems that needs attention. VCDS indicate many of the common problems, so far nothing major though.

Now to my problem... I think I have read all the threads on AW related to the keyless functionality and it's problems but I just can't my head around how exactly it is supposed to work. Currently I can open the doors and start the cars with the key in my pocket. I can also lock/unlock the central locks with all external handle buttons except the one on the drivers door. Finally, I can open all doors (and the trunk) by pulling the handle twice. First time it unlocks the central locks, second the door is open.

I get the impression, that there should be some kind of proximity sensor in the handles that actually should do the unlock when I put my fingers under the handle instead of having to pull the handle the first time for the unlock. Is this correct?

If yes, then the trouble shooting. From reading the archives I got the impression that if a specific handle is problematic (drivers I guess in my case, the non-workning button) the proximity stuff isn't working on that specific handle. The rest of the handles should still work. Am I correct about this? On my car I cannot trigger anything just putting my hand inside the any of the handles.

OK, what does the computers say?

Here we have something:

<snip>
Address 05: Acc/Start Auth. Labels: 4E0-910-131.lbl

1 Fault Found:
00179 - Access/Start Authorization Antenna; Drivers Side (R134)
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 4
Fault Frequency: 0
Reset counter: 109
Mileage: 251424 km
Time Indication: 0
Date: 2019.05.22
Time: 20:44:38
</snip>

And another one:

<snip>
Address 25: Immobilizer Labels: 4E0-910-131.lbl

1 Fault Found:
00179 - Access/Start Authorization Antenna; Drivers Side (R134)
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 4
Fault Frequency: 0
Reset counter: 109
Mileage: 251424 km
Time Indication: 0
Date: 2019.05.22
Time: 20:44:38
</snip>

Can the above problem cause the symptoms I'm experiencing or are the keyless functionally actually working just fine (the double handle pulling)?

If there's a problem, is it the external door handle on the drivers side where I should start looking (code + broken button)?

TSHong

Yes, the way it should work is when you put your hands underneath the handle, it should unlock without you pulling the handle to unlock.

Not sure if the 000179 code is the culprit. Will any of the other doors unlock without pulling on the handle?

vajper

OK, that's why I was asking. No other door works that way. That is, putting my hand in/under the handle doesn't trigger anything on any door. When I bought the car I cleared out some low power conditions on the Battery Regulator but those were caused by low-power conditions due to a faulty battery during winter storage. Those errors have been cleared out and I haven't seen them since then. Thus, probably no low-power mode causing the proximity stuff to be shut down.

But back to 00179, what part is causing that? Either a faulty door handle or a handle with broken wiring (seems to be not that uncommon when reading the archives)?

I

ScottCNelson

Here's the advanced key unlock logic. It seems everything goes through the driver's handle and drivers side aerials. That's German engineering for ya.

vajper

I put great trust in German engineering =) Thanks for the excerpt, need to get used to look at those SPPs!

I'd say the description of the unlock logic doesn't really 100% say that the driver side handle must work but it seems very plausible due to things not working in my car and it is indicated as faulty.

Feel like I'm repeating myself, anyone have experience with this error? To me switching handles may solve the bad button on the handle but the antenna error seems like it is caused by bad components in the J518 control unit.

91quattro

I can unlock my car by putting my fingers under any of the 4 door latches. Granted, I have replaced the driver side door latch, and the handle, I had intermittent issues with both. Do you have the soft close feature?

I have also found that the key needs to be reasonably close to the latch you are trying to use, as in, is your body between the keys in your pocket and the door handle? Distance is kind of sensitive.

vajper

I have the soft close feature but it only works on the right rear door, don't hear any motor sound from any of the other doors so a guess is that the switch in the latch mechanism is broken rather than the cable between the motor and the latch.

I'll try to put my fingers under the other handles with the keys really close to the door. Don't think that will make any difference because the key seems to be detected (possible to open door by pulling the handle twice).

91quattro

Yes, microswitch in latch can go bad, so soft close doesn't work. Some can take the latch out and repair the switch, I decided to get a new latch. The battery in your fob may also have an impact, but it sounds like the driver's latch may be the culprit.

vajper

For the soft close I'll order a new latch and replace the current. Then I can repair the other one and mount in the rear door.

When it comes to the keyless stuff I'll order some components to have a look at the J518 keyless/entry control unit. Seems easier to start there than pulling the door trim =)

vajper

Does anyone know if the R134 antenna is integrated in the drivers side door handle? That is, replacing the handle gets me a new antenna?