F355 Alarm Question

tony,
If the alarm light stays lit, that means that there is an error with the alarm system.
Only way to diagnose is through use of the SD2 tester, unfortunatly only available at the dealer.


Best regards, Jim

 

tony - your problem is likely that the battery housed in the alarm unit at the front wheel well is dead or dying. which is to say that it is no longer recharging properly and/or holding charge. this is a common problem - these things were not engineered properly. my 355 went through two of these units in less than five years. my 550 is on its second or third in the same time period.

purportedly, the part was updated at some point and it now has a separate lead back to somewhere to keep it properly charged - but don't quote me on that.

doody.

 

Its over $500 for the siren unit, which, as far as I can determine, has no other function than to sound a chirp.
Everything else works as it should with the unit out of the car.

 

my understanding was that if the battery in the siren unit flat-out dies, that the alarm system will cease functioning altogether. you can lock the car, but the alarm will never activate.

but again, don't go trading stock on that data - i could be wrong.

i dug up the paperwork from the replacement i did on my 355, and it was $500 including diagnosis, labor, the part, and sales tax.

doody.

 

oh tony tony tony.

NOTHING is ever that easy ;-)

it's buried in there. it's about 6" high by 3" square the top third of it is siren and the bottom third is some POS rechargeable battery.

doody.

 

I have gone through three of these units. The alarm LED will light continuously although everything will still work.

The problem is that the NICAD cells suffer from memery effects of the recharge cycle and asa result do not last at all well.

2 years seems to be it. It seems to make matters worse if the main battery has been allowed to go flat previously, then the siren battery is relucatant to take up the charge.

I understand that ferrari did do an update on this, ite very easy to remove and its a small unit about 4in x5 that just plugs in

 

Its easy to get to from under the left fender. take off the left plastic undertray. Two bolts and a plug.

pic here http://www.boschusa.com/images/business/vehiclesecurity_image.jpg
its the black piece in upper left corner

 

I heard that if you turn off the battery switch that it will eventually drain your alarm battery. I never turn off my battery switch, and always leave my battery hooked up to a battery tender when stored. There is a corrrelation between the main battery and the alrm battery ( as someone alluded to in a previous post). I have yet to experince the alarm battery problem.

 

Easy,
Boschusa.com,
automotive origional equipment,
electronic systems,
vehicle security systems,
VOILA
If you get a new one, and don't want the old one can I try fixing it. you have to saw it in half to get inside. If the circuit board is OK, it might be fixable, Mine was burnt, NG

 

That's easy too, when I took it out it had the Bosch name, logo, and part number on it.
I've tried without any success to get one. Seems you have to go through Ferrari as the coding on the PC board is proprietary. This is typical for OEM suppliers.
When you get it out you will see that its a $20 part at best. That's why I am put out that Ferrari gets over $500 for it.
A TV remote is an order of magnitude more complex.
I will happily pay shipping, after all I live all of an hour away

 

I am having an alarm issue as well and in the process of diagnoising the problem I think I stumbled upon a confirmation of your problem. after unplugging the alarm siren and battery I experienced the same condition you speak of - i feel it is definatly your alarm siren module

 

When i removed the siren/battery module the dash LED stayed on continously when the car was running. all other funtions (other than the siren chip of course) opperated normally. when the engine is turned off the LED flashed as normal.

to get to the module on my 1998 355 F1 and have room to work I did the following:

remove driver front wheel
remove front underbody panel ahead of wheel - 6 screws
remove panel inside wheel well - 4 screws
module is located just ahead and above of the windshield washer bottle
remove alarm/battery module - 2 bolts
unplug electrical connector - difficult to get to until the module was unbolted and hanging

there was previous discussion about the part being sealed. there are two screws under rubber plugs but there does not seem to be a way to separate the two sides of the part. appears to be sealed, but the connecting screws would indicate differently. used a volt meter on the 4 contacts of the connector but did not get a voltage reading from any of them. perhaps someone else knows a way to check the battery voltage.