All,

Been looking for a battery drain on my 07 1.3 GP MultiJet:

https://www.fiatforum.com/grande-punto/442627-battery-drain-problem.html

The immobiliser warning has come on (car symbol + padlock). This hasn't happened before - even with the recent battery drain problem.

Left the battery disconnected overnight, and re-connected (fully charged) battery this morning, but it is still there.

Can anyone suggest how to reset it/clear this, as I can't start it...

Thanks in advance/paul

Charge or replace the battery.
Check fusebox for water under it.
Check ground cables for corrosion.

Try spare key.

Check battery earth cable is solid

Try jump lead between battery negative and engine block

Check ECU earth cable is secure

Thanks cmosfxx & Andy for replies & suggestions:

1. Freshly charged battery (gave 12.8 V when I connected it) didn't clear it
2. Spare key also didn't do it
3. Ground points looked OK, but removed & cleaned (wire brush/emery) chassis point (by washer bottle), one on engine, and one next to ECU - still the same (immobiliser icon still there, won't engage solenoid for starting)
4. Fuse box innards looked dry - tried to remove it anyway, but couldn't undo the connectors from underneath (looks like the grey plastic should slide back, but it wouldn't go - not sure what I'm missing here)

Just a thought: is there any kind of sequence to "re-synch" the key, if they aren't being recognised by the ECU - e.g. lock/unlock, then try to start? Tried to find the owners manual, only to be told it had got wet and been thrown out

Starting to think I'll need to get a mobile auto electrician across tomorrow...

Thanks again/paul

You have to plug a diagnostic tool and read the stored errors then. Don't let the immo light fool you, this can mean a voltage problem somewhere and have nothing to do with the actual immo/key etc.

I still believe the problem is electrical (fuse/relay/cable problem)

Keep us updated!

Quick update: went to have another go at getting the fusebox out, yesterday. Reconnected the battery just to try it first, and it worked - started, no immobiliser symbol, with either key.

Strongly suspect the problem was damp in the fusebox, as cmosfxx/Andy suggested. Took a lot of care getting the cover fitted properly this time (not 100 % sure it was fully locked-down before).

So far, so good... will also get an OBD code reader, in case the immobiliser problem happens again, to give another option to try to fix/reset.

Thanks again for the suggestions & useful pointers/Paul