Sienna 2000 - horn works only when car is not moving

[biharibabu]

I have a strange problem with my Sienna 2000 with 123k miles.

The horn works fine when car is in "Park" with engine running or stopped. It works also when car is in running at < 5-10 miles / hour. But it stops working when the car is moving at higher speed.

The pattern is very consistent. The Van has no problems otherwise and drives very smooth with no vibration etc.

I will appreciate any suggestion to resolve this issue.

[Frank_Van]

My Sienna 1999 has similar issue. Have you figured out how to fix the problem?

[biharibabu]

Not yet.

[dave2001auto]

I fixed the 2003 horn by tripping the alarm using the panic button. The horn work now. Don't know why tripping the alarm fixed it.

[deanalt]

I assume you are refering to a factory alarm system, i.e., that has a panic button, and that uses the car's horn to sound an alarm? Also, did you have the same symptoms as the beharibabu did (and I do) that the horn stopped working at higher speeds (although for me it is merely intermittent)?

Do you think an after-market alarm system could casue the same problem, too? After 8 years of not causing any problems, and given that this alarm system does not use the horn, but has its own siren?

Thanks much
DA

[deanalt]

Biharibabu,

Did you ever solve your problem? Does the horn work sometimes at high speeds but sometimes not? That's what mine does.

Thanks
DA

[dave2001auto]

I'm contacted Toyota Nation and Local to no avail. I checked the wiring diagrams, the for the steer wheel switch, the horn circuit doesn't use the computer. The horn uses the computer only for the alarm. I have concluded that the alarm activation to fix the horn was just coinicidence in my case. I've tested the relay common relay and it is working. So the problem is likely in the steering column / steering coil wire. I've tested the coil wire (which is expensive and a common problem). It's not the coil. The center shaft seems to be losing ground, I've couldn't get a straight answer from Toyota on how the shaft is ground. Looks like it might be by the C ring and washer on the upper portion of the steering shaft. Not very robust, but would explain why the horn comes and goes.

[deanalt]

It looks like I have, at long last, solved the problem on my 2000 Sienna. Apparently, the intermittent horn was due to a grounding problem, as others here have described. An automotive electrician ended up running a wire from the ground wire of the spiral cable that goes to the cruise control system directly to the steering column shaft and that fixed it. He said the shaft ground was interimittent and suggested something about the tilt mechanism, although I may have misunderstood the tilt comment. He said it was a bad design to have the grounding set up the way it was, just as Dave has suggested.

Unfortunately, before doing that, he convinced himself (and still remains convinced) that the spiral cable was bad and first replaced that. When the interimittency returned, he assured me that the sprial cable was bad in addition to something else, the something else being the grounding problem he later found. I think he is convinced that the spiral cable was bad (I could not fully understand the tests he ran to convince himself of that), not just becasue, if it wasn't, he would have had to eat the expensive cost of the part. Between the visit to diagnose, then the second visit after the special order spiral cable came in, plus the 3rd visit to fix the ground, they must have spent 8 hrs labor, for which they could only charge me their original $140. Aftre he fixed the ground, he just did not want to try it with the old spiral cable, since the problem had been interimittent, and I was just happy that they were finally done, having watched them for 6 of the 8 hours. So, all in all, I'm not unhappy with the result.

Anyway, I thought I should add my voice to the chorus of grounding problems in these Sienna models, and perhaps other Toyotas. It seems that the problems started after the vehicle had been driven 90k miles and was initially temperature and vibration related, later only vibration related. Ultimately, with the steering pad disassembled, he could reproduce it by minute movements of the steering wheel.

[Airjer_]

How can you not be happy with the end result? It is fixed right? You said yourself that you where only charged a minute fraction of what you could have been charged for the time they put into the vehicle? Not everything is yes or no, black and white, or has one easy solution. Intermittant problems are not easy or always possible to figure out. Once you find a problem your so happy that there is something to start with you go with it. Why would he keep checking for another problem if he is confident his results prove the part is bad?

I'm not defending or saying anybody is right or wrong but you had a difficult situation to figure out and whether or not anything was broke or bad the end result is you still received a heck of a deal on a diagnosis and repair.

[deanalt]

I don't know what axe you have to grind - perhaps you are a great mechanic who is asked to deal with tough, intermittent problems often - but I think your attack is excessive. Though I, arguably, got a deal on the extended labor, it was possibly extended only becasue the electrician initially misdiagnosed the problem as being due to the spiral cable. If he did, two of my three trips there were unnecessary. He replaced that special ordered part and sent me on my way, and that was after I had to return a 2nd time for the specially ordered part. After the replacement, if he had taken 10 minutes to road test it, he would have almost surely have seen the interimittency recur, as we did within 5 minutes when we drove home. The shop had closed for the day and so we could not immediately take it back, requiring another, i.e., 3rd trip.

I may well have paid $250 for a part that didn't need to be replaced. I will never know, but it seems like a heck of a coincidence that the new part solved nothing (creating the EXACT same symptoms as before)whereas the grounding fix solved everything.

Also, this shop was 20 miles away in a crappy part of town where I had to spend many hours, stuff I didn't feel was necessary to mention, lest I seem like an elitest. Twice during the three trips, I noticed that the electrician was looking at a wiring diagram from the wrong car, so he was a little disorganized - to be kind. Also, the main point of my post was to talk about the grounding problem.

I thought my e-mail suggested I was somewhat sympathetic to the difficulty of solving interimittent problems, in this case one that my independent Toyota shop would not even tackle. I said I was "not unhappy". Apparently, that was not good enough for you. Sorry.

In any event, the point of my post was not really to complain but to add further chorus to the issue with steering wheel grounding problems on Siennas, so I hope we can let this rest.

I wish you peace in your life!

D

[Airjer_]

I'm sorry you interpreted that as an attack?

[deanalt]

I appreciate the response. I may have over-reacted. There is a lot behind the scenes, times when I thought they had taken my car more apart than they should have needed to, and would not get it back together. Times when i felt that, if I didn't watch their every move, they would read the wrong wiring diagram, etc, etc.

Not to mention the 6 months waiting for the problem to get less intermittent and mechanics refusing to work on it or telling me they would charge me even if they could not find it.

Not to mention a wife who lost confidence in the car, while the horn remained broken, and decided she needed a new one!

I wish he had been willing to put the old spiral cable back for a test but he wasn't and I was too drained to push it. So, I'll never know!

Yes, the car is fixed and I am relieved.

Take care.

Actually, I'm not sure this is a proper forum for this, but I'm sure someone will edit it out if it's not:

On both this problem and another problem with my Toyota (which I 90% fixed myself with his help), my frustration was noticably lessened by a wonderful, Toyota master tech who goes by SkyVisions on Justanswer.com. If you have a Toyota problem, he will be a wonderful resource for you. This is not an endorsement of justanswer.com overall, just this one guy there in the automotive forum, Ask for him and accept only him. Some of you folks may be so expert that you don't need it but, if you need some help with a Toyota, he is the man! He provided lots of guidance that helped the aforementioned local automotive electrician (not a Toyota specialist) rule out many issues that could have distracted him from solving the problem.

[dave2001auto]

Originally Posted by deanalt

I wish he had been willing to put the old spiral cable back for a test but he wasn't and I was too drained to push it. So, I'll never know!

What how exactly did he fix the bad grounding on the shaft? Is there a brush on the shaft or only the C-ring to the tilt plate?

Do you still have the spiral coil?

Dave

[dave2001auto]

How is the ground mad to the tilting plate and from the staft to tilting housing or other ground?

[deanalt]

I don't understand your question Dave, and I don't think I will if you clarify it either. I will repeat what I posted earlier, that he inserted a wire which he spliced into the ground wire of the cruise control part of the spiral cable to somewhere right on the metal steering column shaft. I don't know that I can give you any more detail than that, because I glimpsed it from a distance. It seems to have solved the problem which definitely seems to have been an interimittent ground, which would seem to make sense to a layman for an intermittent horn. I recall there was some sort of a little metal screw going perpendicularly into the steering wheel shaft plate and that he just soldered a tiny metal circle to the other end of his new wire and then backed the screw out, and put the end of his new wire on and screwed it back down. I guess that he was making sure the steering shart woud be grounded by tying it into a ground wire in the spiral cable. But perhaps it is the other way around and I am confused. Sorry.

Here is what I said earlier in my post before I got off track about whether or not the spiral cable also needed to be replaced. That repalcement alone did not solve the problem one iota. After the grounding fix, all was fixed.

An automotive electrician ended up running a wire from the ground wire of the spiral cable that goes to the cruise control system directly to the steering column shaft and that fixed it. He said the shaft ground was interimittent and suggested something about the tilt mechanism, although I may have misunderstood the tilt comment. He said it was a bad design to have the grounding set up the way it was, just as Dave has suggested.

HTH,
Dean