Alarm Siren spontaneously going off

Allan- It thinks someone is trying to steal the car, so a loose connection sounds like the most logical problem. If it is not seeing power from the car battery, it will go off.

Once the fob sends the signal to the ECU to tell the Motronic it is ok to start, it is out of the picture.

Taz
Terry Phillips

 

I'm assuming you were furiously pushing the button on the fob while the siren was screaming at you but with no effect?

Since I have the same siren (Corvette) you have me a bit concerned.

Please keep us posted on the outcome

 

Allan- There is nothing in the tech data about the fob being required to do anything but start and there is no signal from the fob until the button is depressed. I think you can start any Ferrari with that fob system and leave the fob at home and the car will run fine. Just do not shut off the engine for more than 60 seconds or no restart.

The alarm system in our Ferraris is 1980s technology, alkaline battery and all, and the proximity fobs did not come out until the 2000s.

Sounds like you have an intermittent connection somewhere, maybe the direct line from the battery to the alarm system and siren for keeping the battery charged.

Taz
Terry Phillips

 

One more question, did the light (red LED) on the dash come on when the siren sounded while driving?

I don't believe there is a "call and response" (proximity) function.

It's not out of the realm of possibility that you simply have a problematic alarm siren.

A difference in operation I've noticed between the Corvette module and the Ferrari is that unlocking gives three beeps instead of two, and the emergency function only flashes the parking lights, but does not operate the high pitched siren like Ferrari module does

I was just out in the garage playing with it and now the alarm system is operating the central locking system after five minutes even though the manual specifically says it does not operate the locking system. Weird, because it hadn't done this in the past. I wonder if it only happens it its locked and unlocked without a drive cycle. I'm doing this with the red fob as my black fobs are being cloned. Does that make any difference?

 

I have had similar problems with my 575. The first time I found that the hood was not quite latched all the way. It looked closed at first glance, but was not. I looked stupid driving down the street with the alarm going off, bit it was an easy fix and keeps me humble.

The Second time I used the "magic" red key fob and it fixed the problem. Not sure if it will fix your problem, but it worked for me and was free.

Also, until I used the red key fob to fix it I just locked it with the key instead of the remote so the alarm would not set. I had a waiter in a restaurant come to my table and ask "sir, is that your Ferrari outside." That is usually a cool question that most people would love to be asked, but he tells me my alarm is going off........well, again, felt kinda stupid.

Good luck.

 

Dave- No difference in day to day operation between red and black fobs. The red fob's PIN is only used when the alarm ECU is being reprogrammed to accept a new set of fobs.

Allan- Another opportunity to pull a headlight on a Maranello, not sure about a 456.

Taz
Terry Phillips

 

I just now drove it down to the corner and back. Now it's only chirping two times on unlock.

I'm wondering if it has something do do with the fact that I had one corner jacked up pretty high when it was in the garage and it recognized a theft attempt.

I'm guessing the drive cycle cleared it.

Still can't figure out the auto locking on the doors though. It looks like if you just get out after a drive it doesn't lock the doors, but if you lock the doors then unlock, open and do not drive or re-lock it will lock itself after five minutes. There is nothing about this feature in the alarm manual.

Be careful as this can lock the keys in the car if you happen to just leave them on the console as I often do when at home or the race track. (We always leave our keys in the car when in the paddock in case someone has to move the car when you're not there.)

 

Taz, I was under the impression from something I was told 12 years ago when I bought the 355 that thieves using a code receiver could open and start your car if they were able to pick up the transmitted code. I was told that if I thought I might be in that situation I should use the red fob because the code was rolling and the transmitted code would not work twice.

Are you positive that the black fobs also use a rolling code?

I have two fobs that have sat for years in the house and never has one of them required more that one press to transmit a working code. How are they keeping up with the rolling code if they haven't been used for like 5 years?

Puzzled in Los Altos

 

Dave- I am 100% positive the black fobs use a rolling code because I have the EEPROM rolling code print-outs of all three of my fobs. Nobody can record your transmission and get into your car, just like the garage doors now all use a rolling code for the same reason.

Each fob has an ID memorized by the alarm ECU and each has its own rolling code associated with that ID. So original fobs can sit for years without use and will work on the first press.

Not so for clones, which have the same ID and rolling code start as the parent fob. They can get out of synch, but someone says three presses in 10 seconds will resynch the alarm ECU after is sees three valid rolling codes in a rwo. Have not tried that myself.

Taz
Terry Phillips

 

Thanks Taz, That helps

I'm sending you a PM

 

Dave makes a good point about the " mystery " of the doors self-locking after 5 minutes, and if you leave your keys in the car on the dash, and only have one key, this is a problem. If I drive the car, the doors stay unlocked, but if i just open the doors after the car has been sitting, it self-locks. Weird.

Taz, here's a question for you. When you push the fob button, a signal goes to the FCU. How many other systems receives this signal ? Why do I ask ? Well, I'm just about at the point of having all that 1980's technology removed. I've spent way too many hours studying the manuals, reading these postings about antiquated transmitters, trying to find replacement fobs, searching past owners for PINS, and so on. I like the way my fobs work on my daily, north amrican made drivers - doors lock and alarm sets, doors unlock and so does the alarm. Period.
So, I'm curious as to what the Ferrari techs would need to do to get that nuisance FCU out of the car and what other modifications would need to be made. I'm sure they could figure it out quick enough, but I'm curious myself.

thanks.

 

Terry - I can confirm that. I made the experience just this morning when I wanted to drive to the bread shop. I used the same fob as usual – that worked yesterday perfectly – but nothing happened. I opened the door with the key and (as expected) the alarm went on. So I went back to catch my other (black) fob and all was fine.

I came home to do a search in this forum and found this post from 308 GTB: http://www.ferrarichat.com/forum/showpost.php?p=140181829&postcount=2

I tried it out with my first fob, pressed the button 3 times and next time when I pressed the button the doors opened and all was OK.

I hope that this will help others as well.

Markus

 

Bruce- No clue. The system was set up to prevent theft and sometimes it even prevents the owner from stealing it.

Markus- That should be a big help for owners with cloned fobs.

Taz
Terry Phillips

 

A Clarification on my previous post about the auto locking and number of chirps on unlocking

It now seems that the only time the system will auto lock the doors after 5 minutes is when the system is in theft notification mode. (like if the car has been jacked up ) You will know the system is in theft notification mode when the siren gives three chirps on unlocking.

A drive cycle will clear the theft notification mode.

There is nothing in the manual about this that I could find.

 

Allan, I don't think it 'has anything to do with the siren but only with the alarm itself. It could be this problem was there before and the new siren just revealed it. First it is essential to diagnose what is happening; is the alarm really armed when it happens or is it going haywire by itself, etc. With some alarms it is possible to arm it while driving, obviously setting it off eventually. This can happen if the switch in the fob breaks and gets "over sensitive", inadvertently arming the alarm while in motion.

The temperature dependence you mention strongly points to bad joints in the alarm ECU.