Model 3 - Horn Issue - Check the left side

[radiocycle]

Thanks laudbrian! I have the exact same issue. And* I had a mobile tech come to the house to try and fix it. He even tried replacing the wheel with a new one, but unfortunately it didn't have working scroll wheels so he had to take it back off. He thought that it might be the wiring harness, that is routed to that side, getting in the way. He pushed it out of the way and it didn't seem to help. I called him later, after he had done his best, and told him that it was no better than before. He stated that he tried several other M3s and that they all had horns that worked the same way.
So I have taken to 'just pushing harder' but like others in this thread, I think it could be a safety item and should be addressed. I'm in the SF bay area so I can take it to Dublin. Perhaps they will be able to fix it since they've seen the problem before. I'm so glad I found this thread!
I'll make an appointment shortly,

Thanks,

radio

 

[Moeshorzon]

I had the same issue but the mobile ranger was able to fix it. Here is a screen grab of what he wrote up in the invoice in case it is helpful to anyone else trying to get the issue resolved.

 

[Perry]

Mine doesn't work on the right side. I scheduled an appointment to fix.

 

[Garlan Garner]

View attachment 361137 View attachment 361133

They replaced the entire steering wheel assembly. Unfortunately I wasn’t there, the ranger drove out to my wife’s place of work.

Thanks for the diagram.

I had the horn problem this morning.

I popped out the airbag and found what the problem was.

If you look at the diagram you provided......part number 12 is the actual horn control.

The left circle where the actual 12 is pointing to is the left horn switch and the right horn switch is on the right side.

Now....

The switch is not the problem.

The problem is part number 11 - being supported by part 12 ( horn switch ) on the left side.

Part number 11 is the wiring harness that allows the buttons / lights on the steering wheel to work. Part number 11 ( wiring ) is being supported by part 12.

All I had to do was to un-attach the wiring harness ( part 11 ) from the horn assembly ( part 12 ) and now the horn assembly ( part 12 ) can move freely on the left side.
I then tested it and re-attached the wiring harness to the horn assembly and it took a lot more pressure on the airbag to get the horn to work - if at all.

Sooo…..since the wiring harness attached to the horn assembly in 3 different places....I figure it will be just fine to leave the extra attachment on the left side un-attached as there is PLENTY of support - AND it makes my horn on the left side work just like the right side.

I got to work and did another M3 and his worked just fine now as well. Takes less than 45 seconds.

Step 1. Pop off the airbag
Step 2. Free up the horn assembly from the wiring harness
Step 3. Pop the airbag back on.

OR

call the service person and have them swap out your steering wheel like @Moeshorzon did in his post above.

 

[Perry]

Thanks for the diagram.

I had the horn problem this morning.

I popped out the airbag and found what the problem was.

If you look at the diagram you provided......part number 12 is the actual horn control.

The left circle where the actual 12 is pointing to is the left horn switch and the right horn switch is on the right side.

Now....

The switch is not the problem.

The problem is part number 11 - being supported by part 12 ( horn switch ) on the left side.

Part number 11 is the wiring harness that allows the buttons / lights on the steering wheel to work. Part number 11 ( wiring ) is being supported by part 12.

All I had to do was to un-attach the wiring harness ( part 11 ) from the horn assembly ( part 12 ) and now the horn assembly ( part 12 ) can move freely on the left side.
I then tested it and re-attached the wiring harness to the horn assembly and it took a lot more pressure on the airbag to get the horn to work - if at all.

Sooo…..since the wiring harness attached to the horn assembly in 3 different places....I figure it will be just fine to leave the extra attachment on the left side un-attached as there is PLENTY of support - AND it makes my horn on the left side work just like the right side.

I got to work and did another M3 and his worked just fine now as well. Takes less than 45 seconds.

Step 1. Pop off the airbag
Step 2. Free up the horn assembly from the wiring harness
Step 3. Pop the airbag back on.

OR

call the service person and have them swap out your steering wheel like @Moeshorzon did in his post above.

Will the same procedure apply if I have the opposite problem. My horn works fine on the left but not on the right side.

 

[Garlan Garner]

Will the same procedure apply if I have the opposite problem. My horn works fine on the left but not on the right side.

Hmmmm….I'm not sure.

You can easily pop the airbag out and take a look.

All you need are two allen wrenches or something like that.

There are 2 small holes behind the actual steering wheel around the 4 o'clock and 8 o'clock position. When you stick the allen wrenches in you will feel some spring resistance if they are in the correct position. If they are free floating in the hole then you are in the wrong spot.

Press the allen wrenches in against the spring pressure and the air-bag will pop off. You will see a set of wires going to the airbag and a connector. You can remove the connector as you would any standard connector.

Then you can look at your horn buttons and see if anything is obstructing the travel on the right side. You can use your finger to press in on the circular connector and the horn should blow. If something is obstructing the switch from making the horn work.....just move it out of the way and put the airbag back.

Don't worry...the airbag won't deploy by removing it and/ installing it over and over.

 

[ord3r]

Took it to service in Costa Mesa and they said it is a known issue that engineering won’t let them address until engineering designs a new part. No eta.

I didn’t want to live with that so followed Garlin’s guide. (Thank you! Quick question, how did you know those two holes release the airbag?)

Instead of completely disconnecting the 11 harness, I shifted it left so it forced it down. I also bent up the connector with the blue wire.


Added picture of before, and two of after from different angles.

Before

After zoomed in

After zoomed out

If not no longer hits the harness on the left side BUT the left horn spring on mine felt much stronger in general, so the left side is better but still requires more force.

I was going to try and bend the actual contact down to make it have less force, but I could not pop of the airbag again. No matter what I try now the bottom stays locked in somehow, any idea why or how to get it off again?

 

[Frunkenstein]

I checked after seeing this video a while back and sure enough, it doesn't work on the left side.

 

[ord3r]

Ok so I got it back off and bent the contacts a bit, didn’t want to break so went lightly, and also looped the blue horn wire BEHIND the scroll harness. I did this by unplugging the blue wire thingy and pulling behind the harness.

That seemed to help a lot, still not perfect though. The main design flaw seems to be the plastic piece that the blue wire attaches to on the left side on the left side hits the friggen screw before it engages the horn!! I can see why engineering is waiting for a new rev. I’ll post up a video soon.

 

[ord3r]

Ok, here is the video explaining the design flaw with the left side connector hitting a screw before engaging when force is applied from the left side. This is similar to hitting the far left of the wheel when the airbag is attached, for example by using your left thumb.

 

[Perry]

Ok, here is the video explaining the design flaw with the left side connector hitting a screw before engaging when force is applied from the left side. This is similar to hitting the far left of the wheel when the airbag is attached, for example by using your left thumb.

So why would mine have the problem on the right instead of the left. Is there a design flaw there too?

 

[ord3r]

So why would mine have the problem on the right instead of the left. Is there a design flaw there too?

On my right the connector was not attached to the moving part, and was lower anyway below the screw. In the video you can see how easy my right is to click, scared myself after messing with left and then barely touching right and getting a honk.



Only way to know on your wheel would be to pop off the airbag and take a look. Would be happy to give my thoughts if you can upload a photo with the airbag off.

 

[tpoltron]

I recently noticed the left side horn was not working on our Nov 2018 Model 3. I popped out the airbag and adjusted the left side wire as above.

My left side switch still seemed to be hitting the top of the black torx screw behind it so I removed the screw, put it in a vice between to strips of wood and filed it down a bit, then put it back in. Did not have to remove the horn button assembly, you can bend it around just enough to access the screw. Horn works much better now tho it is still a bit easier on the right side.
Thanks for the tips above.

Oh and I struggled for quite a while to pop the airbag out then realized it was partly because I was using hex wrenches with rounded tips that were sliding past the springs. Something with a very flat tip would have worked much better.

 

[play150]

I have a similar issue (2021 Model 3) where the horn doesn't activate when one presses the bottom half of the horn area. When pressing the top middle, one needs to press hard. I've encountered a few situations now where I'm unable to press the horn in time because of these issues. (I'm just lucky nothing happened despite my delayed honking, e.g when someone pulled into my lane all of a sudden)

But Tesla keeps telling me that nothing is wrong with the horn, or that it's normal that pressing on certain areas don't activate the horn. Thank you for the videos because I was starting to think something was wrong with my expectations for the horn.