ohionick

Hi all I am having a very weird issue. When my car is off the horn works, I can also hit the panic alarm on my fob and the horn works, but when the car is running the horn does not work. Any thoughts?

1eyedjak

I am having the exact same issue. just started . I think its in the software. thats the only recent change recently.

Kansas

It could be a problem with the horn pad if it is similar in design to the one on the 2000 LS400 I used to have which had a similar horn problem at about the 10 year mark. Mine was not repairable due to the horn part of assembly being held together with rivets. My usual indie Lexus repair shop diagnosed the problem cause and obtained a salvage horn pad / air bag assembly at a fraction of the cost of a new one. Total repair cost back then (around 2010) using the salvage horn pad / air bag assembly was around $800.

In my case, the horn pad no long depressed easily when pressed at some points. Sometimes the horn could be made to sound by depressing the horn pad with greater force or pressing the horn pad at different points.

SupraTurbo

Thanks. That sounds like the issue my vehicle is experiencing. Going to try a new horn pad / air bag assembly. Replaced the clock spring and checked all the fuses to no avail.

fwhomeboy

My horn works some days and some days it doesn't. I gotta find the relay. I'll start digging. 2008 460L.

fwhomeboy

Looks like I'll start here. Hmmmm, no relay.

fwhomeboy

Not a simple fuse, relay, horn setup. Well, ain't that great.
HORN SYSTEM DESCRIPTION When the steering pad (horn button) is pressed, a signal is sent from the steering pad through the steering pad switch (steering pad ECU) to the spiral cable. The spiral cable and front light ECU (front controller) communicate via the CAN line. The front light ECU receives the signal and sends it to the vehicle horns, causing the horns to sound.

fwhomeboy

OK, now I see why most people just skip the horn troubleshooting and take it to the dealer. You just gotta have techstream to isolate this problem. Oh well, I gave it the old college try. Good luck guys. I call "Uncle" !!!

fwhomeboy

fwhomeboy

My horn started working again. I checked the connections at the ECU and gave the ECU a few sharps taps. I didn't do anything else. Hmmm. I know it's not fixed, but, it's working for now. I'll update when I find the problem.

fwhomeboy

Well, my horn comes and goes when it wants to. I still can't figure it out yet. When it works, it works like a champ. It's not a hard fault like a broken wire or a fuse. Hmmm. Still digging.

fwhomeboy

Well, just checking in to say, My horn still works about every 3 days. No fix yet.

fwhomeboy

Still no fix but it still works whenever it feels like it. It's gotta be a software glitch. I'm lost.

lwphat66

fwhomeboy

Looks like this horn issue is not an easy problem to isolate.