Hi

 

Octavia Scout 2.0 (2011)

 

I'm having an issue on my vehicle (above) with the alarm and would be grateful if anyone has any experience with something similar and might suggest any diagnostic tricks or repairs. I first noticed that the hazard lights were randomly flashing and I had no chirp on locking/unlocking. After a look on the forum I suspected my alarm siren battery was low/flat so got a second hand replacement on eBay and fitted it today. After fitting the new siren I still don't have a chirp and have uncovered the following additional symptoms:

 

- I have tried to get the alarm to sound (triggering internal sensors, rocking the car, using the key when locked) but get no response - no flashing hazard lights and no siren

 

- I have noticed the little red LED on the driver's door (that I believe should flash to indicate alarm arming/function) does not light at all when the car is locked

 

- The 5A fuse in slot 35 (I think the fuse for the siren?) blows as soon as a fuse is put in, but has held fine when I put in a 20A fuse for testing

 

I suspect the above problems were all present with the old siren unit, and the issue all along has been something else, but I hadn't looked so closely before replacement.

 

I haven't been able to scan for fault codes (but could get a code reader if this would be helpful) and the only thing I've tried is disconnecting the vehicle battery for a couple of minutes to try and reset the alarm.

 

Thank you :-)

Update:

 

- Have checked all the doors, tailgate and bonnet are showing as open/not open correctly on the instrument panel (I expect this rules out a faulty microswitch as a cause of the alarm failing to arm)

 

- Pressing the switch on the B pillar to activate/deactivate the internal movement sensors does nothing (the switch is lit red and stays lit red when pressed) 

Sorry for spamming - I can't find the edit button on my phone. Have managed to use an el cheapo code reader and the following relevant codes are showing up:

 

03156 Sensor for Anti-Theft System (G578) Open Circuit

 

03020 Local databus 2 short circuit

 

01134 Alarm Horn (H12)

 

The top and bottom codes have recurred after clearing all codes and restarting the car.