TT 8N Roadster 2000 01134 - Horn (H12) 49-00

Hello,
I'm having a problem with the alarm system (DWA) in my 2000 Audi TT Roadster. The alarm horn isn't working, and the following error code is stored:

Address 35: Central locking Label file: DRV\8Nx-962-267.lbl
Part number: 8N7 962 267 C.
Component: Central locking system, DWA D06.
Encoding: 14171
Operating number: WSC 00444
VCID: 408B294C40ED2B46CA-4EE6

Sure, here is the translation of the text from German to English:

"1 error found:"
01134 - Alarm horn (H12)
49-00 - no communication


I was on vacation last week with my car, and based on my experience, I would really like to have a working remote central locking system again. My alarm system is triggering and "flashing." Unfortunately, the horn doesn't work.

"I have the horn installed in the water tank, and it works when I temporarily bypass it with 12V from the battery. It's a "normal" horn with two wires: brown (ground) and yellow/black (signal wire to the central locking control unit?). It doesn't have a backup battery like some other TT models. I temporarily installed a multimeter instead of the horn, triggered the alarm, and checked the signals." Variable signals are arriving in the MV range (similar to CAN), which seems quite strange to me. Actually, shouldn't there be a switched 12V signal at my car alarm system?

I must also mention that the TT received a new comfort control unit this spring. It was a used unit, as the old one was defective and no communication was possible after water damage to the rear window. The code could not be read from the old control unit, and the current code is 14171. The convertible top, central locking, wind deflector, etc., are all working perfectly. However, the DWA horn doesn't work...

Perhaps you have an idea about how I can proceed, or where the error might be?

Here's another recent scan:


VCDS Version: DRV 17.8.0.1
Data as of: 20170809 DS276.3

Vehicle Identification Number: VD 555 555
License plate: VD 555 555
Mileage: 136,600 Repair order: AC



"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein wunderschöner Tag, um spazieren zu gehen oder ein Picknick im Park zu machen. Viele Menschen genießen das gute Wetter und verbringen Zeit im Freien."
"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein wunderschöner Tag, um spazieren zu gehen oder ein Picknick im Park zu machen. Viele Menschen genießen das gute Wetter und verbringen Zeit im Freien."


Vehicle type: XX (8N - Audi TT (1999 > 2007))
Scan: 01 02 03 08 15 17 22 35 37 45 55 56 76 77

Vehicle Identification Number: XXXXXXXXXXXXXXXXX
"Der schnelle braune Fuchs springt über den faulen Hund."
Address 01: Engine Control Module
Label file: 06A-906-032-APX.clb
Part number: 8L0 906 018 M
Component: 1.8L R4/5VT G 0002
Encoding: 05710
Operating number: WSC 00421
VCID: 397D44A823377A8E8D-5120

No error codes found.
Readiness: 0000 0000

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 03: Brake Electronics Label file: DRV\8N0-907-379-MK20-E.lbl
Part number: 8N0 907 379 E.
Component: ESP 20 CAN V004
Encoding: 18446
Operating number: WSC 01236
VCID: 3E7757B43A195DB6B8-4AE6

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 08: Climate Control/Heating Module. Label file: DRV\8N0-820-043.lbl
Part number: 8N0 820 043 A
Component: TT-KLIMAVOLLAUTOMAT D03
Encoding: 00040
Operating number: WSC 01236
VCID: 285B91ECC89DF306E2-2572

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 15: Airbag
Label file: DRV\8N8-909-601.lbl
Part number: 8N8 909 601.
Part: Front and Side Airbag 1005.
Encoding: 10102
Operating number: WSC 01236
VCID: 77F9829055A3ACFEBB-5120

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 17: Terminal block module Label file: DRV\8Nx-920-xxx-17.lbl
Part number: 8N1 920 860 J.
Component: COMBINATION INSTRUMENT + TRIP COMPUTER. M73 D54
Encoding: 05144
Operating number: WSC 00645
VCID: 3A7F5BA42631719684-4ACE
XXXXXXXXXXXXXXXXX AUZ5Z0A9112039

No error codes found.
or error codes are not supported by the control unit.
or communication errors occurred.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 22: All-wheel drive
Label file: DRV\02D-900-554.lbl
Part number: 02D 900 554 B.
Component: HALDEX LSC ECC 0006.
VCID: 1F498A309DD334BE93-4AE6

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 35: Central Locking
Label file: DRV\8Nx-962-267.lbl
Part number: 8N7 962 267 C.
Component: Central locking system, DWA D06.
Encoding: 14171
Operating number: WSC 00444
VCID: 408B294C40ED2B46CA-4EE6

Sure, here is the translation of the text from German to English:

"1 error found:"
01134 - Alarm horn (H12)
49-00 - No communication.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 45: Interior monitoring. Label file: DRV\8E0-951-177.lbl
Part number: 8N7 951 177.
Component: Interior monitoring system. D14
Encoding: 00001
Operating number: WSC 00421
VCID: 7BF19EA0698B889EDF-5120

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 55: Headlight range adjustment. Label file: DRV\4B0-907-357-AUT.lbl
Part number: 4B0 907 357.
Component: DIMMER SWITCH D004
Encoding: 00010
Operating number: WSC 01236
VCID: 65C5D8D8FF0F2E6E19-5196

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 56: Radio Label file: DRV\8D0-035-1xx-56.lbl
Part number: 4B0 035 186 D
Component: Radio D05
Encoding: 00013
Operating number: WSC 01236
VCID: 214D8CC8ABA7024EA5-4ACE
Note: Too many communication errors.


End----------------------------(Duration: 03:36)-----------------------------

Hello,

Was your central locking system/alarm system encoding possibly changed?

Can the alarm horn be activated using an actuator test in the corresponding control unit, or does it remain silent?

Best regards, Rainer.

Hello Rainer,
Thank you for your feedback...

The coding was a "problem" because the old control unit (J249) had water damage and could therefore no longer be read. The new, used control unit was programmed with 04698 (Roadster semi-automatic convertible top, alarm system), and it worked perfectly, but I already had the same error code then. Currently, code 14171 is programmed. The alarm system is "active," and I can confirm the alarm via the turn signals. Therefore, I don't think it should be a programming error.

I'm also reading fluctuating voltage signals with the multimeter in the millivolt range. My understanding is that, in the event of an alarm, a 12V signal should be sent to the horn. It looks like a bus signal, which is a bit surprising to me.

"So far, I've only bypassed it manually using 12V from the battery, and the horn works then. To my knowledge, there isn't an actuator test for the alarm horn." Is there a way to do that via VCDS?

Quote:

To my knowledge, there has not been a functional test for the alarm horn. Is there a way to do that via VCDS?

"Good question. My DWA (Digital Window Actuator) isn't original... Was an identical control unit installed back then?" It seems like the current DWA (Driver Warning System) wants to control the horn via CAN, but the horn simply expects +12V.

Best regards, Rainer.

Hello Rainer,
Thank you. The DWA (Digital Waveform Analyzer) was originally installed. I will take a closer look with an oscilloscope this weekend and examine the signal in more detail. "It's likely that there's a broken cable, which is preventing a verschandeln 12V signal from reaching the alarm horn and activating it..."

charmilles wrote:

Hello Rainer, Thank you. The DWA (Digital Waveform Analyzer) was originally installed. I will take a closer look with an oscilloscope this weekend and examine the signal in more detail. Probably, there is a broken cable, which is why a verschandeln 12V signal is not reaching the alarm horn for activation….

Theoretically possible, but I would have expected an error message more along the lines of "short circuit to ground" or "short circuit to positive," etc.

Best regards, Rainer.

Okay, that sounds plausible... I'll read more signals this weekend and see what it might be.

I will also try programming the control unit code, as the error might be located there. "There were code changes within the year 2000 (week 18, May 1st), and unfortunately, I don't know the manufacturing year of my "used" control unit... If none of this helps, I will try connecting a different DWA (alarm system) horn as a test."

Here is a list that will help with coding.

Coding Usage Vehicle Remark
00000 Basic encoding, spare part.
04672 until week 18/00: Coupe, Roadster with manual convertible top.
04682 " " with DWA
06720, starting week 18/00, Coupe, Roadster with manual convertible top.
06730 " " with DWA
06720, starting week 27/01, Coupe, Roadster with manual convertible top.
06986 " " with DWA Generation II
04688 until week 18/00: Roadster with semi-automatic convertible top.
04698 " " with DWA
06736, starting in week 18/00: Roadster with semi-automatic convertible top.
06746 " " with DWA
06736, starting week 27/01, Roadster with semi-automatic convertible top.
07002 " " with DWA Generation II
DWA = Anti-theft alarm system (optional equipment).
KW = Calendar week / year (production time).



Values for function selection

Bit | Value to set | Function | Remark
0 00001 Rear hatch unlocking. When the rear hatch is mechanically unlocked, it opens. The rear hatch can therefore be opened without using the remote control. Irrelevant for TT.

100002 Warning lights illuminate when the DWA (Driver's Warning Assistance) system is activated.

2 00004 Central locking system (SZV): If the central locking system is activated only once (using the key or remote control), the driver's door and the fuel filler door will unlock, while the passenger door remains locked. If the central locking system is activated a second time immediately after the first activation, the passenger door will also unlock.

3 00008 Activate anti-theft system / Enable or disable anti-theft system.

400016 Semi-automatic convertible top.

5 00032 Automatic door locking at a speed of approximately 15 km/h.

6 0064 Comfort closing/opening via the remote control: Holding down the unlock/lock button on the remote control will automatically open/close the windows.

7 00128 Right-hand drive.

8 00256 Rear door logic DWA. Alarm cycle sounder for RDW. Required for DWA Generation II.

9 00512 Warning lights when closing via the radio remote control. Confirmation of locking via the radio remote control (1 flash).

10 01024 Horn sound (DWA): A short tone from the DWA alarm horn when the vehicle is locked. Not allowed in Germany since 2001.

11 02048 Window lifters, USA logic: All window lifters are disabled when the ignition is off and the driver's door is open.

12 04096 Warning lights flashing when unlocking via the remote control.
Confirmation when unlocking the doors or tailgate via the remote control (2 flashes).

13 08192 Enable radio remote control Enable/disable radio remote control.

Do you perhaps still have the VAG part number from the old control unit, or a car scan (which should contain it)?

Then we could take a look to see if there are any differences regarding the encodings.

Best regards, Rainer.