Alarm - False Activation. Help Please?

[worroourkid]

Hi, my Skoda Octavia Estate is possibly the best car I have ever had (5 years now), that I keep professionally well maintained (not a Skoda Dealer), and have had no issues in that time.

 

Recently however, the Alarm system has been firing off intermittently. I have taken the car to my regular engineer who has given the battery and charging system a thorough check and clean bill of health so,  using the old "look for the simple things first" principle I was hoping you fine folks could answer a couple of questions.

 

1. Would simply dis-connecting and re-connecting the battery "re-set" the electrics, including the alarm, (similar to the old computer "switch it off & switch it on again remedy)"?

2. I have never understood the door pillar switch; what it does or how to use it, could this have any effect on the issue?

3. Should the car "self-lock" if just left; I thought it should did but last night it did not?

4. Finally, I read on another post on this forum that locking with the key should isolate the alarm but currently mine does not.

 

Sorry if I seem a bit dim, but as I said, the car is so reliable, I have never before had any issues or reasons to to ask advice.

Thank you for looking and any thoughts or advice would be greatly appreciated and accepted.

 

Thank you........Brian.

[Vrsburnzy]

1: doubt it

 

2: it turns the interior sensors off so you can lock the car with a dog or kids inside for example, I’m not sure if it also disables the tilt sensor too so it can be pressed when on a ferry or anything that mean the car will sense movement.

3: it will self lock if is programmed too, but self locking is deactivated as soon as you open a door or the boot, and this is in regards to cars without keyless entry, a common problem is people unlock their car and the door micro switch is broken so the car then self locks itself usually locking the owner out.

 

4: not sure to be honest usually that is the case.

 

i recently had an alarm problem on my A6 of same vintage and I plugged VCDS in and it gives you the alarm trigger codes, so it takes away the guessing, mine turned out to be the rear hatch setting the alarm off which in turn was the wiper motor leaking onto the central locking motor and corroded the electrical plug contacts that set the alarm off intermittently.
 

Edited 16 December, 2019 by Vrsburnzy

[pikpilot]

Most common cause of uncommanded alarm activation is the alarm battery nearing end of life. The battery is part of the alarm unit and Skoda recommend changing the alarm unit every six years. They have been known to last over 12 years but more and more people are reporting alarm failures at 6+ years.

 

Do a search on the forums and you will find much advice from a) where to find and how to remove the alarm unit b) experts only - how to change its battery and c) where to buy a replacement unit cheaply in China.

[KenONeill]

(4) in the OP normally disables the volumatic and vibration sensors, which is very useful on, for example, ferries.

[pastiche]

Believe it or not, September is the month of spiders coming out, often I find one on the mirrors surviving  a journey of umpteen miles . They seem to get in places, Last time we all had a hot spell my alarm was off and on constant at night times . My Skoda mechanic lowered the "whatsit" so being less sensitive it has not come on . Of course when tested the alarm does go off as intended/

[AndyDoc]

vrsburnzy, can you tell me how to find the alarm triggers in vcds as I have only just bought vcds and have tried to do the very same thing as I have an alarm fault but can not find how to view the triggers. Many thanks 

[moley]

On 15/12/2019 at 12:26, worroourkid said:

2. I have never understood the door pillar switch; what it does or how to use it, could this have any effect on the issue?

The door pillar switch is to deactivate the internal sensors. I prefer double pressing the lock button on the remote. When you lock the car the red light on the top of the drivers door card flashes slowly, if you press lock and then press again a few seconds later the car remains locked, but the sensors deactivate and the red light on the door car stops flashing. If the alarm still goes off it won't be the internal sensors.   

[Vrsburnzy]

53 minutes ago, AndyDoc said:

vrsburnzy, can you tell me how to find the alarm triggers in vcds as I have only just bought vcds and have tried to do the very same thing as I have an alarm fault but can not find how to view the triggers. Many thanks 

I think 46 CCM controls the alarm, you’ll need to go into meas blocks on there and flick through the blocks, I can’t remember off by heart unfortunately, if I get chance tomorrow I may be able to go take a screen shot.

 

all 4 blocks will be populated with a single digit number iirc, each block you hover the mouse over will give you the legend for the numbers, first block will explain what 1-4 mean, for example 1= driver door activation, hover mouse over second block explains what 5-8 mean and so on.

[AndyDoc]

Thanks for the prompt reply Vrsburnzy, I will have another go tomorrow. I have trawled through all the resources that I can find, both on this forum and Ross-tech but do not seem able to find a step by step guide on how to use vcds so the going is a bit slow for my poor old brain!🤔

[Vrsburnzy]

I’m sure you’ll get the hang of it, will be just getting used to the layout 👍

[silver1011]

On 15/12/2019 at 12:26, worroourkid said:

3. Should the car "self-lock" if just left; I thought it should did but last night it did not?

 

If you unlock the car, but do not open a door for 45 seconds, then it will relock automatically.

 

If you do open a door, then the relock function is disabled and the car will remain unlocked for as long as you don't lock it manually.

[silver1011]

As mentioned the most common cause of unwanted alarm activations is a failing siren back-up battery.

 

After that it is weak pressure sensors / microswitches in any of the four doors, the boot and the bonnet.

 

Disable the interior sensors by using the button on the interior A-pillar and see if the unwanted alarm activations stop. If they do then the internal sensors are either faulty, or there is something in the car triggering them.

 

After that I'd look to replace the siren (behind the drivers or passenger side wheel arch liner).

 

After that I'd be looking at each of the 6 door triggers. The one for the bonnet is the one that causes the most issues.

 

The easiest, quickest and most cost effective way would be as mentioned above, using VCDS diagnostics software to pinpoint what part of the car is triggering the alarm.

 

Edited 29 December, 2019 by silver1011

[Vrsburnzy]

@AndyDoc I’ve updated the thread so other people can use the knowledge too 👍

 

as I mentioned above, control module 46, then onto meas values.

 

type 018 into group and press enter, this will give you sounder triggers, I currently have a sounder fault so maybe why I’m getting the does not respond message.

 

 

Press up or type 019 and enter, I’ve also got an interior monitoring fault too but I’ve got to check if I even have them first 🤣

 

 

Press up again or 020 and enter, then we get onto alarm sources, these are the last 4 alarm sources, so for me it’s been “rear right door” and “drivers door” one after another.

 

 

your car will only auto lock if it’s been programmed like that, our Octavia wasn’t programmed for auto lock, whether it’s been changed from factory I couldn’t tell you, but with VCDS you can go into coding and change all these values but I’d wait until your comfortable and have a bit more knowledge on the matter before going into coding procedures, don’t get me wrong it’s not rocket science, but you just need to be ticking the right boxes and pressing the right buttons otherwise you might put controllers into fault 👍

[worroourkid]

Thank you fo your replies, plenty to consider there! 

Right now, the problem seems to have corrected itself; heaven knows how, but I'm going to leave well alone for the time being and keep my fingers crossed🤞🙏

[AndyDoc]

Finally got to look at my alarm problem with vcds. 

 

              Address 46: Central Conv.  (1K0 959 433 BT)

15:20:34 Group 019: Interior Monitoring (Alarm Trigger)
  129  1st Alarm Trigger 
  129  2nd Alarm Trigger 
  129  3rd Alarm Trigger 
  129  4th Alarm Trigger 

 

15:20:34 Group 018: Sounder (Alarm Trigger)
  1.0  1st Alarm Trigger 
  1.0  2nd Alarm Trigger 
  1.0  3rd Alarm Trigger 

  6.0  Alarm Trigger Counter
15:20:54 Group 020: Alarm Sources
  13  1st Alarm Source 
  13  2nd Alarm Source 
  13  3rd Alarm Source 
  13  4th Alarm Source 

So as you can see a bit confusing. Group 19 Interior alarm gives 129 when it should be 0,1,2,3 so no idea what 129 means. 

Group 18 Sound alarm trigger gives 1.0 which is the comfort control module.

Group 20 alarm sources gives 13 which is central electronics control module.

 

I have looked at the repair manuals and can only find one module which is the "convenience electric central control unit" J393 behind the dash. I believe the error codes must all refer to this just giving it different names. If anyone can confirm this I would be grateful.

As sods law would have it the alarm has not gone off anymore. 😂

[pikpilot]

On the Mk1 Octavia , as they got older the same problem occurred due to dirt on the interior monitor sensor. The fix was to use a vacuum cleaner to gently clean out the accumulated dust, spiders etc through the slits.

On the Mk2, the sensor is at the rearmost part of the interior lights/sunglasses holder assembly - the bit with the slits.

 

Not heard of anyone needing to do this on a Mk2; you may be the first. It is so simple to do that it seems worthwhile trying it.

 

You probably know that you can disable the interior monitor using the button switch at the bottom of the B pillar or, on most models, by blipping twice when remotely locking the car. See handbook for details.

[Vrsburnzy]

I’d be inclined to go onto the rosstech forum and ask what is classified as a C.E.M trigger, it’s not clear what it means, is it being woken up? Is it a tamper signal? someone on the forum will be able to hopefully answer the question taking the guesswork away 👍