Got a 2010 Skoda Fabia 2 (1.4 Tdi) & the siren started sounding today about 30 secs after locking the car. 

 

Checked that all windows/hatch/bonnet were closed & did a vcds scan which showed no fault codes

 

Its been a hot day here & was wondering if the radiator fan may have kicked in after switching off after Id been for my drive, & whether this may have triggered it?

 

I just did a general scan, but could I delve deeper into vcds to see what set if off? Any setting I could check?

 

Ive read in the manual that the siren may need replacing after 5 years or so - where is this located?

 

Also Ive tried pressing the button on the drivers door to deactivate the sensors but it doesnt seem to change colour or click when pressed - is this how its supposed to be?

Edited 5 June, 201610 yr by nia573

You should be able to see the last trigger in the measured values for alarm (09 central electrics).

The siren is mounted in the centre of the plenum under the wiper scuttle trim.

Haha very good! I do like it when I see these topics, my car has been having an alarm issue since February..

One question, do your lights flash when the alarm goes off?

Press the button in the drivers door panel, and lock the car within 30 secs. Alarm deactivated. The button doesnt change colour. Must be done everytime you lock the car.

Edited 5 June, 201610 yr by xman

Im not sure if the lights were flashing actually - its the first time Ive heard the alarm sounding so it caught me by surprise!

 

I went into 09 central electrics & looking at the measuring blocks no groups corresponded with the alarm system?

 

I then had a look at Address 46: Central Conv & saw the following values for the alarm

 

128  1st Alarm Source 

  160  2nd Alarm Source 

  160  3rd Alarm Source 

  160  4th Alarm Source 

 

Do these values mean anything?

Ahh ok. Then yours must be an early 2010 car without a BCM. Yes those are the values to look at.

Thanks

Ive just had a look at the button in the drivers door.

From my understanding with the ignition off, & if I open the door, pressing the button should change it from a red colour to orange, then locking the car within 30 secs will de activate the interior sensors?

 

Well when I press mine it stays red & doesnt change to orange at all

 

Could this be related I wonder?

Alarm just went off again & these were the values that popped up

128  1st Alarm Source 

  128  2nd Alarm Source 

  160  3rd Alarm Source 

  160  4th Alarm Source

 

When the alarm was sounding the indicators were flashing, but the headlamps were not (is this is how it should be?)

 

From a google search does the 128 source relate to the interior sensors? ANy suggestions as to what to do next? Thanks

Edited 7 June, 201610 yr by nia573

According to my info 128 is drivers rotary switch. 32 is interior monitoring.

My interpretation:

The 1st to 4th alarm source is the alarm history.

1st being the newest, 2nd is the next, and so on. So when the alarm goes off, the latest source is stored in 1st position, with all former position data shuffled down a position, the old 4th dropping off completely.

Alarm sources are stored as binary bits, so 128 is bit 8 - the rotary switch, 32 is bit 5 - imterior monitoring.

160 is 128+32, both bits were active when the alarm was triggered.

The question is what is the "drivers rotary switch"? Is it the ignition switch? In that case it looks as if it has an intermittent connection or wiring fault.

Rotary switch in drivers door is what I understand it as.

If you want to rule out interior monitoring simply press the lock button twice.

Ah cheers thats interesting. I've pressed the lock button twice for now to attempt to rule the interior sensors out.

What is the rotary switch, the actual locking module inside the door?

Was wondering if the interior sensor button on inside of door was faulty too since it stays red when pressed?

Cheers for any help!

Could it be the alarm backup battery dying? When the backup battery was going on parents Saab it would randomly go off.

Ah cheers thats interesting. I've pressed the lock button twice for now to attempt to rule the interior sensors out.

What is the rotary switch, the actual locking module inside the door?

Was wondering if the interior sensor button on inside of door was faulty too since it stays red when pressed?

Cheers for any help!

The rotary switch is part of the lock module. It would be worth checking in measured values, it might be stuck showing an unlock signal?

I've only ever seen the deactivation button light up red.

Ah thats great, thanks

 

Someone mentioned on facebook that the siren battery could be a culprit - better to replace the unit or is it possible to open it up & replace the battery itself with one from maplin etc? Any ideas of cost for the siren & part no's?

 

Might need some guidance regarding what to look for with the measured values etc - Im new to using vcds 

 

I thought that I read somewhere that the door switch changed to orange when pressed

2013 monte - interior monitoring button alway showed red and functioned as it should. I have never seen it any other colour.

Sent from my iPad using Tapatalk

thinking about it wouldnt I have had a alarm source code relating to the horn if the battery in that was at fault?

 

Might it be worth looking at the loom from the a pillar into the drivers door just to check whether the wires are not chaffed or broken?

Afaik there is no "backup battery". Why would there be? In case someone nicks your main battery?

In 12 years of fabia ownership, never had to change this mysterious battery.

You have a dicky door lock switch, imo, have you tried simply locking/unlocking it mechanically with the key just to exercise it and clean the contacts a bit? At the same time check the windows wind down/up functionality (by holding the key in lock/unlock positions)

Edited 8 June, 201610 yr by xman

I thought the alarm sirens needed an internal battery, so that they sounded if the main battery feed from the car was cut or tampered with

 

This article deals with replacing the siren & opening up the old one (in russian but you get the idea)

http://skoda-ural.ru/repair/remont-zamena-sireny-shtatnoi-signalizatsii-na-a-m-skoda-octavia-a5-fl

 

Ive just tried locking & unlocking using the key in the barrel of the door handle & the windows go up & down fine

 

Should the windows drop & raise if I hold the lock/unlock buttons on the fob too? (like it does with the Mk5 Golf). Mine doesnt do this (another pointer towards a faulty door module?)

 

Cheers

To check if you have this mythical battery, lock the car with the bonnet open and remove the main battery negative terminal.

If the siren was at fault that would have its own source code. The system is telling you why the alarm is going off, that needs investigation.

Yes the siren has an internal battery, it's even part of the service schedule to change it.

In which area & What sort of values need I be looking for The drivers side door lock? Is an easyish job to replace them? I've done a mk5 golf but that had quite good access since the outer doorskin came off

Access is easy, door trim off and remove a foam cover.

Is the lock sticky?