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jst4show2.8
11-18-2014, 11:09 AM
So my inspection is about to be up and i am running into some problems and cant really seem to find a fix. My horn will not work for starters and dunno where to start looking at the problem, i have taken the air bag off and looked at the clock spring and everything seems ok there, looked at the connector behind the bag and not seeing issues there. Checked fuse box and not an issue there either. Do you guys have any ideas?

The second issue i am having is a p0011 code and that also is not leaving me much to work with. The po said that he installed a new module and it shouldn't be giving that code. Do you guys having any idea what could be causing this. The car is a 01 a4 1.8 quattro avant.

Racingmax53
11-18-2014, 11:19 AM
Dude this is wild. I have an 01 A4 1.8T and my horn stopped working yesterday, and I am getting P0012 along with a misfire in 3... What is going on. Will be watching to see what happens with the horn issue. I need to check the fuses.

jst4show2.8
11-18-2014, 11:38 AM
dunno if this has anything to do with it, but my air bag light is on could that cause a problem?

biketsai
11-18-2014, 12:19 PM
dunno if this has anything to do with it, but my air bag light is on could that cause a problem?

If you have a bad clockspring, it will throw an airbag light and your horn will not work. You cannot visually look at it and tell if it is good or not. Get your car scanned, it might help you out. I haven't heard of a fuse blowing for the horn, but I have also had my relay go bad for the horn.

jst4show2.8
11-18-2014, 12:42 PM
I was told the air bag module was bad.. When I have it scanned no codes show up


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MetalMan
11-18-2014, 12:52 PM
I was told the air bag module was bad.. When I have it scanned no codes show up

If the airbag module was bad it wouldn't be able to be scanned or would throw a fault code for a memory fault.
Can you confirm that the airbag module could be accessed via VAG-COM or VCDS?

jst4show2.8
11-18-2014, 02:27 PM
i took it to a friend who was a different scanner not a vag and it showed it could not communicate to the airbag module, but is the horn connected through that module or still possible a clock spring issue

walky_talky20
11-18-2014, 02:53 PM
No, the horn is not connected through the airbag module. That would be silly. Like Jaguar level of silly.

I'm not understanding the "looking" at all the parts. They generally don't hold up signs saying "I'm broken. PICK ME!". We certainly wish they did, but most often they do not.

For electrical diagnostics, if you really want to go down this path, I would suggest you start at the symptom and work toward the source.

Step 0. Check Horn fuse. 25A Fuse #40. This just makes good sense to do first. Check both contacts with a test light with key ON. Don't just look at it.
Step 1. Unplug Actual Horn.
Step 2. Put 12v across horns. Careful not to crap yourself if they work.

No worky?: Replace horns.
Crapped yourself? You can clean up later. Keep going.

Step 3. Put test light across horn harness. Turn key ON and push horn button.

Lights up?: Bad contact at harness connector. Clean all pins and you're done.
No light? Keep going.

Step 4. Reference your wiring diagram (WAIT, you're doing electrical diagnosis without a diagram?!?) and see that the next device upstream is the horn relay. Go there.
Step 5.
etc.
etc.

My limited experience tells me that you are likely to find one of the following (in order of most likely to least likely):
- Horns are just faulty.
- Clock spring is broken.

jst4show2.8
11-18-2014, 03:39 PM
No, the horn is not connected through the airbag module. That would be silly. Like Jaguar level of silly.

I'm not understanding the "looking" at all the parts. They generally don't hold up signs saying "I'm broken. PICK ME!". We certainly wish they did, but most often they do not.

For electrical diagnostics, if you really want to go down this path, I would suggest you start at the symptom and work toward the source.

Step 0. Check Horn fuse. 25A Fuse #40. This just makes good sense to do first. Check both contacts with a test light with key ON. Don't just look at it.
Step 1. Unplug Actual Horn.
Step 2. Put 12v across horns. Careful not to crap yourself if they work.

No worky?: Replace horns.
Crapped yourself? You can clean up later. Keep going.

Step 3. Put test light across horn harness. Turn key ON and push horn button.

Lights up?: Bad contact at harness connector. Clean all pins and you're done.
No light? Keep going.

Step 4. Reference your wiring diagram (WAIT, you're doing electrical diagnosis without a diagram?!?) and see that the next device upstream is the horn relay. Go there.
Step 5.
etc.
etc.

My limited experience tells me that you are likely to find one of the following (in order of most likely to least likely):
- Horns are just faulty.
- Clock spring is broken.

well what i was referring to when "looking" at it was to make sure all the grounds where good no broken wires etc..

quattro_sinko
11-18-2014, 06:32 PM
well what i was referring to when "looking" at it was to make sure all the grounds where good no broken wires etc..

let me finish that sentence for you, "....oh, and by the way, thanks for posting the diagnostic check-list! Beep! Beep!"

walky_talky20
11-19-2014, 06:18 AM
I lol'd at Beep. Funny guy.

OP: I realize now that my comment had a condescending tone, making me come off like a pretentious douchebag. While that may or may not be actually true, the tone was not intended. I meant just to explain that with an electrical fault, looking usually won't get you very far. (Unless someone has, like...stolen your horns.) While using your eyes is always important, testing that your wires actually have power or ground present, continuity, etc, will tell you a lot more about why you gots no "beep beep out the sys'm".

nautica tuner
11-19-2014, 12:35 PM
I just wanna share my experience with a bad horn. I messed up putting back the airbag when I replaced the ignition switch. What happened is that I wasn't able to tighten it properly with the 2 torx bolts. It's like the airbag got stuck in the steering wheel and it doesn't move when you press it. I replaced the steering wheel that came with an airbag (for aesthetic purpose) and my horns went back. Prior to that, I did the 12v test as suggested by walky_talky20 and found out that my horns are ok. So I narrowed it down to the trigger. I didn't check the fuse though.