Hi All

My father-in-law owns a 2000 Fabia Elegance TDI and has an annoying fault where the alarm keeps going off randomly!!

I have read several threads where this seems to be a common problem with the interior sensor being at fault. I know someone who has VAG-COM and has plugged in to which has revealed that there is a fault with this sensor.

Can the sensor just be unplugged (hence a cheap fix) or does this have to be replaced with a new one (cost approx £60?)? It is just that f-in-l being tight and also not being bothered about his Fabia being alarmed!!

Advice greatly received!!

Many thanks

Dan

Hi I have this intermittent alarm fault problem too (along with a few others) on my Fabia 2000 hatchback. According to the dealer, the fault is either with interior sensor or door sensor (having done VAG-COM). To cut a long story short however, despite logical argument they told me they cannot disable it but can only replace it.

Anyway I thought this was absolute cobblers (although obviously a free new working sensor would be best). I've now become so annoyed by the problem I decided to read more about the interior sensor and then take thing into my own hands. The sensor is indeed accessed via the interior light, but it is not part of that assembly. To reach the sensor you first need to remove the translucent plastic with a small flat blade screwdriver, then undo the two Phillips retaining screws. Next pop out the two side lamp push-buttons with a screwdriver. You will then be able to prise the whole plastic lamp holder assembly from the ceiling with a screwdriver by depressing the 2 lugs at each side. The whole thing will hang out and if you look just inside the ceiling behind the hole there is a 5x5cm black box stuck (with sticky pad / tape) between the roof panels which is the sensor.Pull this out and you will notice a 3 position slide switch on the side of the box marked + o - (mine was in the - position). Unfortunately changing the setting of this switch did not seem to noticeably affect the sensitivity of the sensor as the alarm still triggered when i tapped it. (I also note mine is made by Cobra AG + Skoda Auto and has multiple numbers incl Part No 6Y0 959 121). Anyway in the end I just disconnected sensor from the 4-pin minature socket, and bingo... sensor problem solved!

..... or so i assumed until the alarm kept going off! :eek: I could not believe it - despite the fact that the garage had me booked in to fit a new interior sensor next week, removed or not, the alarm is still playing silly buggers and I still don't know where the fault is. So much for the diagnostics! Or maybe the garage's lack of diagnostic skills... who knows.

Next plan - disconnect siren (however, I have not yet managed to find anything - including my hand that I can fit between the plastic at the bottom of the windscreen and the bonnet bulkhead to reach the siren connector without removing everything).

I'll keep you posted!

You may have the same problem that I have had recently, which was down to poor solder contacts in the front passenger door switch. Do a search on faulty central locking, there is plenty of info. Try here:

VWvortex Forums: MKIV door locks explained - why you're having problems!!! :(

To identify which door may be causing the problem, disconnect the bottom (white) multiplug at the relevant door pillar at each door in turn. This will isolate the door lock can bus system from the convenience unit and alarm - it will revert to manual lock/unlock but when the alarm stops playing up, that's the door to sort out. Another suspect is the bonnet microswitch, but I think that also stops wipers working if that's duff.

Hi I have this intermittent alarm fault problem too (along with a few others) on my Fabia 2000 hatchback. According to the dealer, the fault is either with interior sensor or door sensor (having done VAG-COM). To cut a long story short however, despite logical argument they told me they cannot disable it but can only replace it.

Anyway I thought this was absolute cobblers (although obviously a free new working sensor would be best). I've now become so annoyed by the problem I decided to read more about the interior sensor and then take thing into my own hands. The sensor is indeed accessed via the interior light, but it is not part of that assembly. To reach the sensor you first need to remove the translucent plastic with a small flat blade screwdriver, then undo the two Phillips retaining screws. Next pop out the two side lamp push-buttons with a screwdriver. You will then be able to prise the whole plastic lamp holder assembly from the ceiling with a screwdriver by depressing the 2 lugs at each side. The whole thing will hang out and if you look just inside the ceiling behind the hole there is a 5x5cm black box stuck (with sticky pad / tape) between the roof panels which is the sensor.Pull this out and you will notice a 3 position slide switch on the side of the box marked + o - (mine was in the - position). Unfortunately changing the setting of this switch did not seem to noticeably affect the sensitivity of the sensor as the alarm still triggered when i tapped it. (I also note mine is made by Cobra AG + Skoda Auto and has multiple numbers incl Part No 6Y0 959 121). Anyway in the end I just disconnected sensor from the 4-pin minature socket, and bingo... sensor problem solved!

..... or so i assumed until the alarm kept going off! :eek: I could not believe it - despite the fact that the garage had me booked in to fit a new interior sensor next week, removed or not, the alarm is still playing silly buggers and I still don't know where the fault is. So much for the diagnostics! Or maybe the garage's lack of diagnostic skills... who knows.

Next plan - disconnect siren (however, I have not yet managed to find anything - including my hand that I can fit between the plastic at the bottom of the windscreen and the bonnet bulkhead to reach the siren connector without removing everything).

I'll keep you posted!

Did you manage to sort this problem?

Dan

It's normally the interior sensor, there was a Technical Bulletin ages ago about it.

I had this problem for years on a 2000 Fabia Elegance. The dealer replaced the interior sensor under warranty, but it did not solve the problem. They eventually reduced the sensitivity, so they said, and although this seemed to reduce the frequency of the problem, it did not stop it completely. The weather seemed to be a main cause, and I was able to disable the alarm by pressing the key fob twice when locking the doors, but this had to be enabled by the dealer. In the end, I just learned to live with it. Interestingly, at work there is someone with a 2000 Fabia Elegance and sometimes when I lock or unlock my car it causes their alarm to sound.

The factory siren is mounted at te rear of the car behind a shield just next to the fuel tank.

Mine now keeps bloody going off at will, I have lubricated the bonnet sensor as it seems dry as a bone.... and it seemed to help.

Can I just take the plug off of the bonnet switch and short it across temporary as I can disable the interior scan with a double press of the key but the alarm still goes off.

The only way to stop it is to leave the car open.......has anybody any ideas??????

Edit:

Would somebody like GSF do these sort of parts? or does anybody know anywhere else?

Cheers!!

Edited 18 January, 200917 yr by Conshine

Well I may have solved my cause of this problem - I probably haven't left it long enough yet (<1day) but alarm usually goes off within an hour or two of locking car, so I'm hopeful! I had previously disconnected the interior sensor and checked fault codes but these didn't seem to tell what had triggered the alarm as they didn't change. I haven't explored the door locking mechanism connections but I do have intermittent trouble with the rear nearside door lock unlocking itself a few times when I'm trying to lock the car so that could be faulty.

Basically - i found a broken fuse in the junction box on top of the battery and this had resulted in the ABS light coming on (although it was intermittent but recently has stayed on). While looking for a solution to the ABS problem I may have fixed my alarm problem. See my post here! 00301 - ABS Return Flow Pump (V39) - BRISKODA - The Skoda Forums

If I don't post an update then you can assume this has stopped my alarm problem completely.

Edited 30 June, 200917 yr by docdlb

In the meantime I had changed the siren tone/region to "Germany" using VAG-COM which stops the tweeting alarm and just leaves a slightly more bearable horn sound!