360 engine immobilizer keeps blowing the fuse

The 5amp fuse powers:

Siren
Anti-lift sensor
Some circuits in the Immobiliser ECU
Something in the Alarm Interface Unit

It's possible that you have a battery leak in your Siren which is shorting something on the internal circuit board. It's not the easiest thing to get to and there are no disconnects between the fuse and the siren, just splices. Do you know if the siren batteries were replaced in the last 19 years?

Maybe the 360 Immobiliser experts can tell you what you can disconnect for faultfinding purposes without immobilising the car or triggering the siren.

Here's an Immobiliser wiring diagram for an older Modena (fuse numbers may be different, but I've shown the 5amp orange fuse in the diagram):

https://www.dropbox.com/t/k58uxrfTlzGW60Yt

Link expires in 6 days

 

Would anyone have a picture of the 360 anti-lift sensor in-situ?

It looks like it is at the base of the steering column:

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It is nearly always a faulty siren module. Unplug it and replace the fuse. Siren is located in the front compartment, same side as the battery isolator switch, you'll need to remove the trim in the front compartment to access it.
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... on RHD cars.

On LHD cars, it's on the other side

 

With the siren missing, I would have thought you would have got a flashing LED when driving.

The wiring diagrams show the car horn wired up to the Immobiliser ECU. However, I don't know if 360's in all countries sound the horn at the same time as triggering the siren.

 

Ian- What Ferrari calls the base version applies to most countries except the US, and the horn does not sound according to the Alarm Manual. On US versions, it does.

Garry- If you can stand the glaring red LED lamp and no theft protection (Ferraris rarely stolen in the US, different elsewhere), no problem.
Mark (gobble) at ferrarifobs.com sells an alarm siren that is much less expensive than OEM. I have one of those myself. Plug and play.

 

Thanks, Terry

Australia seems to follow the US with regards to alarms and engine management on Ferraris. The horn is so loud on my car, I don't think I've ever heard the siren.

Where are you located, Garry?

 

You can leave it out or unplugged. The immobiliser will work fine - i.e. the engine will be immobilised and the doors lock / unlock when you press the fob button.
What you won't have is any sound if the immobiliser is activated (when someone tries to steal the car, or the tilt sensor is tripped) , but with your faulty siren, you wouldn't have had that feature for some time anyway.

 

No way to start her using the PIN or program the Alarm ECU to accept another set of fobs without the siren, either.

 

Hi Terry.
Have you experimented that ?
I have programmed several sets of fobs, and simulated numerous PIN entries, with only the alarm ECU on my test bench and it worked every time. Sometimes I also connected an immo interface and an engine ECU and it was well disarmed by the PIN entry.
I really don't think that the siren is necessary.

 

Eric- No, but in the car most owners need the flashing LED for reference. I have done a few sets of fobs and not sure I could do it without the flashing LED.

 

Terry, even without the siren, the alarm ECU is driving the LED properly so that you can start with the PIN or program fobs. It just maintains the LED constantly lit after the starting process if the siren is not there.

 

This is correct.

 

And to add
The LED staying on ( ie on continously, ) when the engine is running is typical indicator of a siren module with a fault - typically that it's internal battery is failing.

The siren modules have a finite lifetime caused by the internal rechargeable battery failing after many years (and often leaking and damaging the circuit board in the process) , which can lead to an internal short which trips the 5 Amp power fuse for the immobiliser (as the OP found out).

 

Hello Eric!
I am new here and I would like to send you a PM. But I don´t know how this works here. Could you please send me one to get in contact?
MY F1 360 has the problem that the hazard lights are always on. I can pull the fuse of the immobilizer behind the seat after starting, than they turn off. The remote control for the immobilizer does not work. It is also not possible to open or close the car with them.
I would be very grateful for your help!
Greetings Markus!

 

The problem could be your immobiliser is locked "panic mode".
To enter panic mode, you press and hold down a fob for more than 3 seconds. To exit panic mode, you need to press and hold down the fob for 3 seconds. This is explained in the Immobiliser system operating instructions, which should be in the document pouch.

 

Eric- Thanks. Good to know. Never tried it myself since my siren is still working.