Horn stucked, starts and stops, ABS&P/S flashing

[DanieLocker]

Hi All,

I have a 2008, petrol, automatic, 5 doors Aygo. 2 weeks ago I've found high amount of water in the boot and at the rear footwell. 1 week later the horn has stucked (going off), I've disconnedted the Battery and removed the fuse of the horn. After these actions, the car starts, but stops after 1s and ABS & P/S lights are flashing. I've found a topic created many years ago mentioning the same symptoms, but there was no conclusion on the root cause. Any help is really appreciated.

 

[flash22]

Can you hear the fuel pump prime ?

Where was the water coming in from, front or rear ? is the boot wheel well dry, when you say rear footwell as in the rear passengers put there feet or the boot ?

I take it the Aygo is LHD ?

[DanieLocker]

20 minutes ago, flash22 said:

Can you hear the fuel pump prime ?

Where was the water coming in from, front or rear ? is the boot wheel well dry, when you say rear footwell as in the rear passengers put there feet or the boot ?

I take it the Aygo is LHD ?

Yes, I can hear the fuel pump prime.

Yes, it is a left hand drive (I'm from Hungary).

Front footwell was (is) dry, water was coming from the rear, I assume it is the brake light and side doors.

Water has been removed from the boot, let's say it's dry now. Rear right passenger footwell was really wet, left not so, but was also affected. I've attached some images.

Do you think that the horn ON, no start issue is connected to the leaking?

I do really appreciate your help.

BTW. When the horn was ON, first I've disconnected the Battery and after that I removed the fuse cover above the steering wheel, because first I did not know thaat the fuse of the horn is in front. I'm thinking, maybe I've accidentially disconnected the immobilizer?

[DanieLocker]

1 minute ago, DanieLocker said:

Yes, I can hear the fuel pump prime.

Yes, it is a left hand drive (I'm from Hungary).

Front footwell was (is) dry, water was coming from the rear, I assume it is the brake light and side doors.

Water has been removed from the boot, let's say it's dry now. Rear right passenger footwell was really wet, left not so, but was also affected. I've attached some images.

Do you think that the horn ON, no start issue is connected to the leaking?

I do really appreciate your help.

BTW. When the horn was ON, first I've disconnected the battery and after that I removed the fuse cover above the steering wheel, because first I did not know thaat the fuse of the horn is in front. I'm thinking, maybe I've accidentially disconnected the immobilizer?

Furthermore, today I could find one damaged I guess vacuum pipe (see below image).

[DanieLocker]

Now as it is around -5C, the rear footwell is frozen. I can not park in a warm garage unfortunately...

[flash22]

You will need to pull the interior out and dry it out, the rear lights and 3rd brake light are common leak points on the Mk1, not so much the door seals, is the carpet dry above/around the pedals ?

You may have pulled the wrong fuse

[DanieLocker]

1 hour ago, flash22 said:

You will need to pull the interior out and dry it out, the rear lights and 3rd brake light are common leak points on the Mk1, not so much the door seals, is the carpet dry above/around the pedals ?

You may have pulled the wrong fuse

We will work on the leaking issue, I've already ordered a complete sealing package.

But now the bigger problem is, that the car is not moving, so first I would like to solve the "motor starts but cuts" off issue with flashing ABS & P/S.

We will have time to debug the car today, will check all fuses.

[flash22]

water and electricity do not mix if that water is on top of the carpet there must be a load more under it and in the front under the insulation there is no telling what connectors and wiring are like, there are some major junctions in the driver's footwell

no point in chasing problems until you know it's dry

time to check for codes and see if anything is related, the immobilizer uses 3 different power feeds if a loom or connector is wet it will blow a fuse or 2

[alsbazaar]

Hey, I'm having the exact same issues with mine - horn was stuck, so I disconnected the horn fuse (it's the correct one according to the manual) - car drove ok for a few hours with the horn fuse still disconnected (started fine after parking every time) - now it stalls right after start and had the ABS and P/S lights flashing rapidly on the dash. I have tried rebooting the imobilizer by jumping pins 4 & 13 on the OBD port but I have had no results so far. Could you please let me know what the diagnose on yours was? Thanks in advance. Best regards.

[alsbazaar]

Hey everyone, just an update for the steps I have taken to fix this issue, in case anyone 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 + 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

 

All and all this is a very silly safety system issue that is probably triggered by disconnecting the horn fuse. I tried resolving it for 3 days and was about to send the car to the shop to get it looked at, thankfully I tried the keyfob resync as a last-ditch effort before calling in a towtruck, which honestly feels more like an Atari cheat code than actual car troubleshooting. Either way, my car is working now but it will probably be best to do some further investing on what caused the horn to start randomly blaring in the first place so that it doesn't repeat, I've seen people pointing toward the issue being the relay box for the horn, others to the horn button bracket and spring, the issue seems to have subsided for now but I'll come back with more answers if it pops back up again.

Best of luck, hope I could help!