Auris 1.8 hybrid horn doesn't work, alarm keeps going off!

[Carnut1980]

Hi all, if i lock my car with the fob, the alarm WILL go off, within 5 minutes, it is the 'beep beep beep' of the horn!

Now the horn doesn't work, not when you press the steering wheel, but the horn unit itself DOES work, with infra red steering aid (fitted but removable) so passes MOT etc!

I can't help but think that the 2 issues are related?

All windows are shut, boot/bonnet are shut!

I can switch off the internal motion sensor,, but has no effect, the alarm WILL go off, unless i lock with key blade, which is kind of annoying!

The 'break glass' sensor in the boot, is intact, as is its wiring!

No lights on dash, full history, 110k miles!

Any ideas why the alarm keeps getting triggered?

cheers

[DaddyBaddy]

Maybe this is a failed (or failing) disc horn?

You say the horn doesn’t work, but it does work. Did you bench test it to ascertain that?

The horn is behind the grill and the original one will be a DENSO ND-012. That’s what’s fitted to my 2016 Auris Excel hybrid hatchback.

They are exposed and may be victims of stone damage / salt spray / water ingress. If it’s shorted out, that may be causing the false alarms. 
I just tested my alarm. The disc horn beep beep beeps, as well as a secondary alarm sounder which makes a completely different alarm sound. The two alarms sound off together.

 

 

[Carnut1980]

4 hours ago, DaddyBaddy said:

Maybe this is a failed (or failing) disc horn?

You say the horn doesn’t work, but it does work. Did you bench test it to ascertain that?

The horn is behind the grill and the original one will be a DENSO ND-012. That’s what’s fitted to my 2016 Auris Excel hybrid hatchback.

They are exposed and may be victims of stone damage / salt spray / water ingress. If it’s shorted out, that may be causing the false alarms. 
I just tested my alarm. The disc horn beep beep beeps, as well as a secondary alarm sounder which makes a completely different alarm sound. The two alarms sound off together.

 I assume the unit behind the steering wheel is faulty, as the disc horn does indeed emit a loud 'beep' when using the infra red hand held steering aid, and because the alarm sounds identical to someone pressing the horn on and off, i can only assume that the 2 issues are linked!

Is it worth changing the disc horn, even though i know it works?   Could it be a relay issue?

 

 

[FROSTYBALLS]

Is the vehicle a first generation Auris (2007-2012) or second generation (December 2012-2019)?

[Carnut1980]

2 hours ago, FROSTYBALLS said:

Is the vehicle a first generation Auris (2007-2012) or second generation (December 2012-2019)?

Hi , one of the last 1st gen!  The horn WAS operable, from steering wheel, although it needed a good few attempts, but now, nothing!   I'm less bothered about the horn working from the SW, and more bothered about sorting that alarm, so it will lock from fob without going off!

[Carnut1980]

On 6/28/2021 at 1:04 PM, DaddyBaddy said:

Maybe this is a failed (or failing) disc horn?

You say the horn doesn’t work, but it does work. Did you bench test it to ascertain that?

The horn is behind the grill and the original one will be a DENSO ND-012. That’s what’s fitted to my 2016 Auris Excel hybrid hatchback.

They are exposed and may be victims of stone damage / salt spray / water ingress. If it’s shorted out, that may be causing the false alarms. 
I just tested my alarm. The disc horn beep beep beeps, as well as a secondary alarm sounder which makes a completely different alarm sound. The two alarms sound off together.

 

 

Exactly where in the boot, is the glass break sensor?  As i am happy with the 12v Battery, i will try the GB sensor first, then i will check out the disc horn!

[Carnut1980]

On 7/1/2021 at 9:04 PM, Carnut1980 said:

Exactly where in the boot, is the glass break sensor?  As i am happy with the 12v battery, i will try the GB sensor first, then i will check out the disc horn!

**UPDATE**

Got horn working, small metal tab to the side of steering wheel cowling, needed a flat head screwdriver, and moved it a bit.

Alarm still going off when locked with fob!

What if i removed the alarm siren? PN 89040 12010?

Would the hazards still flash when the alarm is triggered?

[DaddyBaddy]

I guess it would still flash but with no siren, unless of course there is something in the siren itself which completes the “alarm circuit”. Like a tamper device.