Need to get it checked over by a specialist.
Best option is probably a Honda dealership.
The bottom line is that the alarm Siren has small rechargeable battery cells, in series, SEALED inside it.
These are to support the alarm in the event of a power failure I presume.
After 'x' cycles of charging and discharging, all rechargeable batteries fail - some are better than others.
I'm on my 3rd Siren now.
After several diagnostics at Honda, they decided that a Siren was required.
As they're a dealer, I needed to contact Honda Customer Services.
FORTUNTELY, one of the Dealership employees offered and did on my behalf.
After being put on hold for the best part of 30 minutes, he got through.
He was asked several questions - confirmation of fault, my car's history including mileage and where serviced - when confirmed as low and always with Honda, he was given a reference.
I would pay labour (~£100, Honda would cover the (~£450) cost of the Siren.
This was very good, but there's more .... it needed to be ordered. No problem.
2 weeks later I called - not in yet, please call back.
2 weeks later I called - 1 month total - same story.
Another month later - 2 months later. Same lady on Service Reception answered with 'There's no record of any Siren ordered nor of a fault Sir'!!
Unusual for me, I didn't explode!! (I can, and badly!!)
I contacted Honda Customer Services by e-mail, and explained ALL details, including this - to P off the Dealership.
Honda replied within 3 days!!
OF COURSE YOUR CAR IS CONFIRMED AS REQUIRING A SIREN AND THAT ARRANGEMENT IS CONFIRMED, NO PROBLEM!!
I promptly called this (not so helpful excuse for a) Lady Service Agent.
NO APOLOGY. NOTHING!! Just YES, WE'RE AWARE OF IT. We've ordered the part.
I simply replied I'll call back within 10 days' time, as I knew she wouldn't call me.
It arrived within 10 days, was fitted, they even forgot to invoice me the labour!!
I had every intention of paying but thought that I'll be as helpful to them as they were to me - let them realise. Took them 2 weeks - incompetent or what!
SERVICE, MAINTENANCE AND REPAIR at Warrington Honda has ALWAYS been 100% - just the people behind the counter weren't.
Lookers were great, the last lot not so, now its under new ownership again ..
I knew they had left 2 wires disconnected when I was left with only the immobiliser, before the new Siren was fitted.
These were for the cabin sensors, located inside the front map light holder.
I thought I'd take a look, as all should be fine now.
NO, THEY HADN'T RECONNECTED THESE - Simple clip together so no big deal.
It's been 100% ever since.
Bottom line, it'll PROBABLY be related to the alarm Siren, based on my experiences.
Al.