Horn Not Working - Toyota Nation Forum : Toyota Car and Truck Forums

vcee12 · 01-15-2010, 06:14 AM

HORN NOT WORKING WHEN COLD (BELOW FREEZING) PANIC BUTTON WORKS ALL THE TIME.

ANYONE KNOW WERE HORN RELAY IS?? THANKS VINCE

inov8 · 01-15-2010, 10:45 AM

What model year Avalon?
I have an '05 and the good news is there are separate horn relays for the security system and horn switch, which might explain why the horn works in one case but not the other. The bad news is that Toyota, in their infinite wisdom, appears to think these relays will last forever. Rather than using a socket so they could be easily replaced, they apparently saved a few pennies by mounting them directly on a board located under the fuse/relay panel in the engine compartment.

Other possible causes include the horn switch, the spiral cable ("clock spring"), and the serial bus body communication system. If you have a warmed-up engine, but low outside temperature, does the horn still fail? Under those conditions the board with the relays would be warmed by the engine, suggesting the problem is somewhere else.

vcee12 · 01-15-2010, 04:07 PM

Thanks For Replie If Its Cold Out It Wont Work. Today It Was 30 Degrees And After A 1/2 Hour Of Driving It Worked. Also Had Steering Colum Replaced Under Warrenty And Has Acted Up After That. Checked Wire On Airbag/horn Button And Thats Ok
Vince

vcee12 · 01-15-2010, 04:08 PM

Ps 2006

boosted-fc3s · 01-15-2010, 04:40 PM

When I saw the thread title, all I could think of was the bumper sticker: "Horn Broken, Watch for Finger"

vcee12 · 01-16-2010, 08:29 PM

Put Portable Heater Under Dash Today And Horn Worked

inov8 · 01-18-2010, 10:40 AM

The Horn circuit signal flow is as follows:

Horn switch
Spiral cable (connection from steering wheel to body).
Combination switch (wiper switch module) serial bus transmitter.
Serial Bus to body computer.
Body computer serial Bus receiver (located under the instrument panel, to left of the steering wheel).
Horn relay (engine compartment)
Horns (via 10A fuse)

Your test result suggests the cause of malfunction is not in the engine compartment. You could try to further isolate the cause by heating just the steering wheel or multifunction switch with a hair dryer while the horn is not working.

vcee12 · 01-30-2010, 06:05 PM

toyota replacing streaging colum saying colum not grounding stay tuned