S4 immobiliser issue - with vid!

[alan s4]

Issue with immobiliser light developed recently:

Switch on bike, light goes out for a few seconds then flashes briefly once and then stays on (see vid). https://youtu.be/Sqs9hbY8WAs

Doesn't seem to be adversely effecting the bike in any way, worried it soon will though.

I've checked the antenna in the key shroud and checked/cleaned the connector blocks for the wiring. Still the same.

Also tried my spare black key and the red code key - get exactly the same result.

Any ideas?

[Luddite]

If no one has the answer on here, try giving Avanti a ring - they have a wealth of knowledge regarding ECUs/immobilisers.

http://www.avantiraceparts.co.uk/page.php?id=29

[alan s4]

Thanks for that, so going with the diagnosis on the website:

Fourth sequence
the LED stays off if engine ignition is enabled;
the LED comes on and stays on if engine ignition is inhibited.

My LED is staying on, "engine ignition inhibited", what does that mean

[Darren69]

LED flashes once?

The I think from Avanti website:-
•if the system is OK, the LED stays off;
•the LED flashes once to indicate that the serial connection is missing (this is the direct connection - through the main wiring - between engine control unit and immobiliser control unit in the instrument panel);

Engine ignition inhibited means you can't start the bike because of a fault possibly the one described above.

[alan s4]

That's the problem, the bike is running fine despite the immobiliser light staying on (see vid).

[Darren69]

Oh I didn't see the vid that the bike was running. That is a weird issue.

[alan s4]

All sorted. Spoke to the extremely helpful Avanti guys as recommended. They thought it was odd that the light was staying on with the bike running, I mentioned that the bike was fitted with a DP ECU, it would appear that my immobiliser has already been disabled at the factory.

I've now disconnected the Antenna and the bike still runs, so nothing to worry about.

Very impressed by the time taken to explain by the Avanti guy, I know where I'll be buying any bits I need for the bike in future, highly recommended

[Darren69]

Yea the DP ECUs don't come coded and so if it was never red keyed it will have the immobiliser switched off, which is probably a good thing. So has the light always done that or just started doing it recently?

[alan s4]

Just recently, the magneti marelli immobilser box (behind the headstock) was still connected, apparently it's very common for this unit to fail (bit like the reg/rect). I've now removed this and the light no longer blinks or stays on. Something worth bearing in mind for all those S4 owners who still have their immobilisers activated - ticking timebomb maybe

[Darren69]

Yes, I don't know if the later ones like mine are better with the immobilzer in the dash unit! Probably even more expensive to repair if it goes wrong.

Hi All,

I was going to reply directly here, but it took Slob far too long to activate my account, and Alan beat me to it!

As above, it's all sorted now but the main concern for me was that the Immo light was on but that the bike still starts on the button. Normally if the Immo light is on, then the engine will be disabled and is not allowed to start; the starter button doesn't do anything at all.

The only situation where this can happen is if the Immo has been disabled in the ECU and the bike is an early model that has the additional Immo box and it's failed, or the clocks & ECU don't match. Because it has only just started happening, we know that the clocks & ECU were ok (paired) so it must have been a dodgy Immo box.

Those little boxes were only used on early models that had the IAW59M ECU, and controlled the Immo setup, rather than it being in the clocks and ECU like the later bikes. They are known to fail after a few years, probably due to cheap components or water ingress, and they can lock the owner out of the bike as they just stop working and don't allow the bike to "wake up" on the key. One day you get the Immo light and no start.

Disabling the Immo in the ECU means that it ignores the extra Immo box and talks directly to the clocks (not caring about serial number checks either!) and will allow the bike to start regardless; the Immo box normally gets huffy and leaves the Immo light on so just unplugging it turns the annoying light off.

Apparently you can still buy new Immo boxes from Ducati dealers - they come in around £130 iirc - but to be honest it's only going to be a matter of time until it fails again, and you need to program the Immo and keys again, which is a real faff, and impossible if you don't have the Red (Master) key for the bike.

I've attached a picture of what the little Immo box looks like for your reference. The box has a Ducati part number of 28640321A (may have been updated; a dealer will know) and is marked with the Magnetti Marelli logo and "IMMO" plus a revision number. They are normally located on the left-hand side of the headstock, but again it depends on the model, so have a rummage!



Hopefully this helps - any questions please fire away and hopefully I can help!

Antony @ Avanti Race Parts