Question about 2004 Toyota MR2

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Intermittent 'horn' alarm noise upon ignition & when turning off

I've recently bought a 2004 mr2 roadster and intermittently the car horn gives off a constant horn noise when I put key in ignition and when I take out again. Does anyone know what the cause of this is?

The private dealer I bought off recommends carrying out a series of steps on the battery to reset to factory settings (holding wires together etc), although Toyota/Friends/Family reckon not to touch this. Car is still under warranty with this dealer so I'm taking back to him to sort out. What's my best approach to ensure he fixes this permanently?

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  • Anonymous Nov 27, 2008

    this guy is not toyota dealer - which is more concerning! I will ask for his documented procedures for repair. I do sense he will try and reset battery as he tried to get me to do - I'm leaving it up to him to sort as I do not want to create another problem. Should I advise him to do anything else?

  • rossimcf Nov 28, 2008

    as expected I went and he reset battery and told me that was what he had been advised to do. No longer than 4 hrs later the problem happened again. How much would it cost for Toyota to fix this problem? It does appear to be an electrical fault although the key immobiliser work fine, its just when key touches ignition slot the horn blares for 4-5 secs and stops when I start car. It also happens when I stop car for a brief 1 sec

  • rossimcf Nov 29, 2008

    I don't believe there are 'aftermarket' items installed. His story was that the remote starter was lost and he had to replace it. It is a Toyota key. Here is some info on the key if it helps: CE0123 CLBT/C/245/2002 Denso 1512v.

    Since replacing the key, the guy said that is when this problem started. I'm assuming that the anti-theft system is the original MR2 Roadster system for 2004 models.

  • rossimcf Dec 02, 2008

    sorry i meant 'key fob' when I referenced remote starter. The car does NOT have remote starter.

  • Toyota Ed May 11, 2010

    You mentioned remote starter... Does this car have a remote starter? MR2s can NOT have a remote starter. That would really screw up the body computer, which would explain your issue.

  • Toyota Ed May 11, 2010

    It would be nice to know what "aftermarket" items are installed on this car...remote starter, anti-theft system, etc....

  • Toyota Ed May 11, 2010

    "Holding wires together" is not a typica Toyota repair procedure.

    The best approach: Get the Service Advisor to document EVERYTHING that was done. Make him/her give you copies of any wiring schematics that were used in the course of the repair, and get as much info as you can. Then, get back to me.

    I can double check their work as I am a Toyota Svc Mgr.



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SOURCE: 95 Toyota Camry Speakers hum and buzz when car is off.

There is a major short somewhere,the hum you hear in the speaker
is the frequency of the DC electricity flowing through the speaker coils,do all four speakers hum or just one?Do you have a stock or aftermarket stereo?

Posted on May 15, 2009

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SOURCE: Toyota Celica '91 ST184R - Key fob remote does not unlock the car

The ST18x didn't come with a factory fitted alarm, so this is going to be more general.

Your alarm will have a manual disarm somewhere. If you have a small cylindrical device with your keyfob, there will be a receptacle somewhere near the drivers seat. You need to open the door and press the two items together. If not, you may have a button hidden somewhere around the place. In this case the procedure is usually to hold the button while you insert the ignition key and turn it to the ON position.

Some alarms have a small round key. If your alarm has one, or if your keys came with one and you didn't know what it was for, you can open the bonnet, pop a little cover on the alarm box (it will be bolted to the firewall, usually on the right hand side as you look at it) and turn it off until you can get it repaired, or get a new one fitted.

If none of this works and your alarm is an alarm only and not an immobiliser, you can simply open the bonnet and cut all the wires going into the alarm. If it is also an immobiliser, don't touch anything unless you're handy with a soldering iron and multimeter and have a few hours spare. (You would need to pull the cover down from under the steering wheel, then start taking electrical tape off the big block connector with thick wires, and then start rebuilding the wiring that's been chopped to make way for the immobiliser system on a colour-matching basis.)

Posted on May 17, 2009

Mr BrokRench
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SOURCE: intermittent non-starting caused by high pitched whirring when key turned in ignition

hello gwolfson...from your explanation it sounds like the starter motor is turning but the bendix is not engaged. This happens over time and is caused by normal wear. A click or clicking noise would point to the starter solenoid. Don't wait until you hear a grinding noise to replace it, thats hard on the ring gear and flywheel. A NEW starter is recommended if you plan on keeping the car. If not, you can go with a rebuilt starter for around 65 dollars. Of course make sure the battery terminals are clean and secure as well as the solenoid terminals.
Good luck...i hope this helps and will fixya up.

Posted on May 29, 2009

  • 1 Answer

SOURCE: My car won't start be cause the alarm sounds as soon as i turn ke

I have a 95 camry 2.2 and it did the same thing. i helped jump a buddy's car then the horn started sounding. so i called the parts service for toyota they told me theres a switch under your dash, on the floor board, right above where the left is placed. there was a switch, he told me to flip it then my car started working no problem. that was about 1 yr 1/2 ago.

Posted on Aug 07, 2009

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SOURCE: toyota mr2 roadster 2001 engine light on code po141 oxygen sens

bank 1 will be whichever side cylinder 1 of your engine is and bank 2 will be the opposite side. It's named bank 1 and bank 2 so that no matter how the engine is laid out, bank 1 is always on the same side as cylinder 1. I cannot say whether the right hand or the left hand one will be bank 1 as I do not know where your cylinder 1 is. The garage should know

Posted on Sep 08, 2009

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Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.

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