Alarm horn fault

[BAIKAR]

After nearly four years of ownership and my car now out of warranty my alarm horn has quit. I used my vcds to run a scan and it showed up as a faulty horn.

Has anyone had to change this unit themselves rather than the dealer? Ive seen on other sites that the unit gives trouble on a lot of models and also within the VAG group.

I gather from searching that it is encased within a metal shield which is riveted to the dsf wheel arch behind the splash guard.

[ZephyR]

Sounds like it could be an expensive job for a fairly simple problem.
If all else fails you could look at wiring a new horn up to the excising horn wiring or relay and abandon the old one.

[RW1]

My alarm horn was changed in warranty at 14 months from new. The main difficulty is removing two pop rivits & fitting the replacements while closing up. Access is restricted around the Horn unit and if not careful, tools like a drill and the pop-rivit pliers can easily cause creases to the outer front wing. The outer wing is not strong and is easily bent (crumple zone).

The fault was DTC 01134 - Alarm Horn (H12) in VCDS. The red LED in the driver's door by the wing mirror would, on locking, come on perminently initially for about 2 seconds, then start its slow flashing.

Left it to the dealer as it was warranty.

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First de-activate the alarm system by unlocking the car and opening a door. As you say, its right hand wheel wheel off, remove the inside wing mud splash sheild. The unit is behind the box shaped stainless steel cover up at the top rear of the front wing/bottom of the A pillar.

This is the more difficult part as you have to drill out the 2 stainless steel rivits (Part No. N 905 113 02) which hold the cover guard on. Access is from above to drill the rivits, so a straight drill has to be small. Drilling out the pop-rivits is done with a 6mm diameter drill.

Having removed the rivits, the horn unit third securing foot is locked into the bodywork slides outwards. Pull the Horn connection cable from the alarm itself through the inner wing towards you so that the plug connection can be separated. Replace with a new Horn (Part No. 1K0 951 605C upto 06.12.10 production build, 1K8 951 605B from 07.12.10 onwards). Re-connect the Horn connector.

In VCDS, clear the fault code.

Shut the door(s) and activate the alarm with the key fob. Check the door red LED on locking the Scirocco rapidly flashes for about 2 seconds, then starts its slow flashing with no Horn activated.

Unlock the car and open the door. Now to fully function the alarm. Follow this topic and select the alarm Horn H12 in VCDS Output Test using Controller 09 - Central Electrics. You will have to cycle through the whole of 09's Output tests until you reach the alarm. The Horn will sound when you activate it and stop when you move VCDS onto the next test. Unfortunately, its the 2nd last test in the list. Exit the Output Tests.

Final check the fault memory is still clear.

If OK, offer the Horn's cover's securing foot into the inner wing and fit/secure the two pop-rivits with the pliers. Apply a little paint and underseal to any damaged areas. Then put the mud splash sheild back in place and tighten the torque bolts (T25, torque: 2Nm - 12 off) and re-fit the wheel. Job done.

C.

[skippy]

After nearly four years of ownership and my car now out of warranty my alarm horn has quit. I used my vcds to run a scan and it showed up as a faulty horn.

Has anyone had to change this unit themselves rather than the dealer? Ive seen on other sites that the unit gives trouble on a lot of models and also within the VAG group.

I gather from searching that it is encased within a metal shield which is riveted to the dsf wheel arch behind the splash guard.

Could be worth still seeking goodwill from VW for a fault such as this, even though the car is out of warranty. I know I would do this, I would normally expect the horn unit to be reliable so could be worth pursuing.

Apart from that I see Chris has given an excellent technical breakdown (as always) of what is involved with this.

[BAIKAR]

Thanks very much for the detailed reply. I have just decided to replace it myself and ordered the parts from my local dealer. The parts come in under £100 at retail so its not too bad. I would be tempted to try the goodwill but I think you normally end up paying for either the parts or the labour and Vw picks up the other. Based on that i reckon i could replace for the same or less than the goodwill option plus i have my own vcds.

I agree that this should not fail so soon especially because it has security / insurance implications. When i called my local dealer they keep the units in stock and have replaced 15 in the last year alone so it must be a unit likely to fail.

[SN10459]

Hello first time posting. I seem to have the same problem with the alarm.. It appears it only goes off when it's raining. Is this more and likely the same problem with the horn alarm?? Had the car for 5 years and had no problems!!

[chelspeed]

I would say not. The horn is a device that makes sound when you put volts on it. If there's no volts to it then it won't matter if it gets wet or not it won't make a sound.

I would think your problem is the alarm itself, it should only send volts to the horn when the alarm goes off. It sounds like it's getting wet and sending volts when it shouldn't.

Pretty hard to accurately fault find something like this on a forum with such little info so don't rely on what I say without looking into it more. But I'd be looking at the alarm not the horn. No idea where the alarm is mind.

[MR13MOS]

Bumping this (very old) thread as my 61' Scirocco's alarm seems to have given up the ghost recently..

Error 01134 Alarm Horn H12 as suggested above.. Dropped the part numbers into Ebay (1K0 951 605D) & have come back with several parts for various other models – Golf, Passat and some Skoda, Audi.

This Passat part looks to be the most suitable - https://www.ebay.co.uk/itm/274011911081" onclick="window.open(this.href);return false;

Anyone able to confirm this will fit for me? Matching part no. so i'm pretty sure it would, just nice to know for sure if anyone could lend me a hand.

Much appreciated, thanks