Horn stuck on when car left off!

[245jhy]

Hi, this is my first post and some what a strange one! I left my car in works car park Friday morning and later on could here a horn continually going off! Went out and saw it was my car, a 2010 petrol aygo. I removed the horn fuse after looking under bonnet fuse area and horn stopped. Then the car started having issues cutting out after starting as if the immobiser was not working correctly etc. Then when it did run ABS light flashing.

I got the car home to inspect it, I cannot get the car running now at all, has anyone encountered any other similar issues? I'm struggling to get hold of wiring diagrams to inspect. Is there a relay for the horn? Or a control module that would theoretically control both the horn/ABS? Any help would be greatly appreciated.

 

Thanks Olly 

[fordulike]

Just out of interest, was it raining, or had it been raining when your horn stuck on?

[245jhy]

It was raining in the morning but nothing torrential. There is some moisture in the car like many aygos from this model year, which is why I though possible control module/ relay issue. I just can't seem to find a wiring diagram for the horn circuit/ if there is a relay! 

[fordulike]

I know this is a stab in the dark, but as you say, it's a strange one. Just before I bought my AYGO, the Toyota dealer had carried out some work, which was logged as follows.

Check & advise horn sounding c, LAMP,CENTR STOP,DUCT ASSY, QUAR,CUSHION

They replaced, sealed, checked the centre brake light?? Not sure of the exact details, but assumed it was something to do with the notorious leaky AYGO syndrome. But what is interesting is the mention of 'check & advise horn sounding'. Don't know whether the horn had been stuck on, or if the centre brake light was related, but might be worth keeping that in mind whilst fault finding.

[245jhy]

It's a very good point, I looked a little earlier and found when I put the car in reverse the horn goes off? I need to continue further tomorrow when I have more time and equipment to diagnose accurately with. I have also seen another post similar to this which reports changing damaged wiring behind dash due to water ingress. 

[brianrfc]

Did you find the problem as I have very same issues the car starts for 3 seconds then cuts out horn stuck on and goes off when I put car in reverse 

[Mike169]

Hi Oliver and all.

 

I dunno if this link is worth a look for you but it certainly worth a peek, lol.

 

https://www.google.co.uk/search?source=hp&ei=W8VUWr5ppY2ABubMtvgD&q=toyota+aygo+horn+stuck+on&oq=toyota+aygo+horn+stuck+on&gs_l=psy-ab.3...3329.14750.0.16952.25.22.0.3.3.0.120.2165.13j9.22.0....0...1c.1.64.psy-ab..0.24.2162...0j0i131k1j0i22i30k1j33i22i29i30k1j33i21k1.0.vy4EaumCUdM

 

Mike.

[Aygo80]

On 11/12/2017 at 5:20 PM, 245jhy said:

It's a very good point, I looked a little earlier and found when I put the car in reverse the horn goes off? I need to continue further tomorrow when I have more time and equipment to diagnose accurately with. I have also seen another post similar to this which reports changing damaged wiring behind dash due to water ingress. 

Did you solve the problem with the horn?

[FROSTYBALLS]

4 minutes ago, Aygo80 said:

Did you solve the problem with the horn?

245jhy last visited the club in November 2017, so you may not receive a response.

[flash22]

Check the horn relay and make sure there is no water ingress, when parking the car turn the steering to the left or right, turn the car off and see if it still does it

[alsbazaar]

Hey everyone, I have posted this same answer in a different thread but here are the steps I have taken to fix this issue in case anyone else comes across this fun artifact in the future.

1. Try to get your car dry-ish - This happened to me after cleaning the interior of my car - I didn't use any water on it but some window detergent might have dripped behind the dashboard and from every account of this issue occurring the common factor has been humidity and water ingress. Last year I had to disassemble and reseal my tail lights and 3rd brake light after they got water in them so I don't doubt that a leak like this could be the main culprit and me cleaning the interiors was completely unrelated (it was also lightly raining that day I guess).
2. See if after drying out the flashing lights on the dash (ABS & P/S) go away, if not disconnect your Battery for a few minutes (30-ish if you want to be extra safe) and reconnect it to see if resolved the issue. If not skip to the next step and retry after doing it.
3. Do the Toyota immobilizer resync procedure by jumping pins 4&13 on your OBD port under the dash for 30-45min. while keeping the key in the ignition in the second to last position (the one before actually starting the car). There are a lot of videos on YouTube documenting this step, I'll leave a link to one of them to further illustrate how it's done.
4. Check if this has fixed your issue by trying to start your car up. In my case it didn't, so I repeated it about 5 times with varying lengths of waiting time and trying a few different things like keeping the side lights on while doing it. (This last one was a real gamble but my Battery was brand new and I heard someone talking about it on a forum so I gave it a whirl, either way, I don't think repeating the procedure changed anything so skip to the next step).
5. Do the Toyota keyfob resync procedure by putting your key in the ignition, turning it on and off, and opening and closing your driver's side door in a specific sequence. You'll know that it has worked once the car locks and unlocks itself. Again, there are videos describing these steps better than I can, so please refer to the one linked. Hopefully, after this last step, the issue should be fixed!

 

Links to the YouTube videos:

Immobilizer Resync

Keyfob Resync

 

Best of luck, hope I could help!

[Paul john]

3 minutes ago, alsbazaar said:

Hey everyone, I have posted this same answer in a different thread but here are the steps I have taken to fix this issue in case anyone else comes across this fun artifact in the future.

1. Try to get your car dry-ish - This happened to me after cleaning the interior of my car - I didn't use any water on it but some window detergent might have dripped behind the dashboard and from every account of this issue occurring the common factor has been humidity and water ingress. Last year I had to disassemble and reseal my tail lights and 3rd brake light after they got water in them so I don't doubt that a leak like this could be the main culprit and me cleaning the interiors was completely unrelated (it was also lightly raining that day I guess).
2. See if after drying out the flashing lights on the dash (ABS & P/S) go away, if not disconnect your battery for a few minutes (30-ish if you want to be extra safe) and reconnect it to see if resolved the issue. If not skip to the next step and retry after doing it.
3. Do the Toyota immobilizer resync procedure by jumping pins 4&13 on your OBD port under the dash for 30-45min. while keeping the key in the ignition in the second to last position (the one before actually starting the car). There are a lot of videos on YouTube documenting this step, I'll leave a link to one of them to further illustrate how it's done.
4. Check if this has fixed your issue by trying to start your car up. In my case it didn't, so I repeated it about 5 times with varying lengths of waiting time and trying a few different things like keeping the side lights on while doing it. (This last one was a real gamble but my battery was brand new and I heard someone talking about it on a forum so I gave it a whirl, either way, I don't think repeating the procedure changed anything so skip to the next step).
5. Do the Toyota keyfob resync procedure by putting your key in the ignition, turning it on and off, and opening and closing your driver's side door in a specific sequence. You'll know that it has worked once the car locks and unlocks itself. Again, there are videos describing these steps better than I can, so please refer to the one linked. Hopefully, after this last step, the issue should be fixed!

 

Links to the YouTube videos:

Immobilizer Resync

Keyfob Resync

 

Best of luck, hope I could help!

What precautions did you take pre washing the interior to protect the electrics?