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Alarm Keeps Going Off - But No Indicators Flashing & No Immobiliser

Nala Nesnej said:
Thanks for the reply Brian. What you say seems to add up. I left the car standing for a week last week, and when I came to start the car, the battery was totally dead - which indicates a dodgy battery. When I went home last night the siren went off. I set off for home expecting the siren to sound again, but it didn't, and today it's behaving itself, so maybe it's charged itself. Still a bit confused as to why the ultra sonics set the alarm off though. I'll wait and see what happens.
aha, yes that's exactly what happens when the siren battery voltage is low but the main car battery is fully-charged, the siren mis-communicates with the MICU and also with the ultrasonics, you have to leave the engine running, shut the doors, and wait about 20 mins for the siren battery pack to reach operating voltage

the "bell box" at my house is the same, if there's a power cut, the "bell box" starts to wail
 
btw if the main car battery is going flat, you might have the dreaded "parasitic battery drain", usually ***ociated with the bluetooth/HFT unit (in facelift 7th gen) but it's also been seen in cars without the bluetooth/HFT
 
Interesting - my battery is a 6 month old genuine Honda one, so it shouldn't be flat after a week, and my Bluetooth/HFT has stopped working. Are the problems related?
 
Nala Nesnej said:
Interesting - my battery is a 6 month old genuine Honda one, so it shouldn't be flat after a week, and my Bluetooth/HFT has stopped working. Are the problems related?
definitely, same amount of certainty as the Pope is a Catholic

several threads on here about the issue

this one shows how to remove the bluetooth/HFT module (after removing it, best place fir it is in the bin)
http://typeaccord.co.uk/forum/topic/1383-hft/
 
I had the Bluetooth/HFT module drawing too much current when off, causing my new Honda battery to completely discharge if not started in 2/3 days.
I have removed the Bluetooth/HFT module for now, until I find more time to work out whats gone wrong with it.
My alarm is still in the same state - disconnected, but still yet to fit in the small button batteries.
 
A belated update. It was exactly what you said freddiefrog. There was a battery drain, so I disconnected the Bluetooth module, and the drain disappeared. It was draining the battery, and once the battery was low, the alarm went off. The low battery level causing the alarm to sound, was comfirmed by the Tech at the Honda dealer.
 
Just to say a big "thank you" to posters on this thread.

My 2008 saloon had the siren randomly going off from time to time, but no immobiliser or or other problems, so it was disconnected and removed as a short term fix, then refurbed with the details above. It went mental when first put back, but after a reset by closing all doors and boot then locking and unlocking all was well, and has been for the last two weeks.

The Bluetooth module has stopped working so has been removed.

The main car battery was getting old and not retaining charge, and was not up to full beans even after a long run.
 
Further update - all fitted and now behaving itself. New battery is 320mAh instead of original 250mAh and is 70% charged as shipped which results in the siren blaring when connected until the car charges it fully. It stopped sounding after a few minutes. Apologies to the neighbours...
 
Hi peeps,

Quick update i ordered my battery from here http://www.xcelplus.co.uk/index.php/honda-car-immobiliser-by-cobra-security-rechargeable-battery-pack.html
the 320mah version however they sent me in triangle instead of straight strip, so to fit i removed existing pack, the plastic tray and fitted inside unit and screwed back up as battery pack was taped up there will be no chance of short also as pack fits snug there is no chance of movement.

A quick tip for you all, when you re connect alarm will wail, close all doors, and unlock then lock car with remote start car and then switch off allow to charge from main battery for at least 30 minutes then use vehicle as normal siren otherwise siren will wail as you drive until main charge restores.
 
I'm not really using my car that much and fitted a battery cut off switch several months ago. I last used the car over a month a go and it's been disconnected since. I'm using it tomorrow so checked the charge tonight and it was almost still fully charged.

I noticed that the indicators were not flashing when I lock or unlock the car, they did when I last used it. I'm going to check everything tomorrow when it's light like the door locks, fuses etc. But came across this thread while googling. I am ***uming by not using the car regularly and disconnecting the battery when it's not used will eventually cause this issue with the siren battery?

I'm really not bothered about the siren so if I can just disconnect it now I will. So as long as I disconnect the plug from the siren (when it's not going off) that's all I need to do or will it sound when unplugged?
 
yes you can use battery optimizer which can be keep battery topped up, you can also disconnect siren, from what i remeber you can just disconnect you will get a red light flashing whenever you start vehicle and a few dtc code is you deep scan other than that wil work as normal.
 
had a semi thorough skim through this thread and a couple others but I'm not sure if the symptoms on my facelift diesel fits the bill

two nights in a row now I've had to disconnect the battery because the alarm will go off, then stop, then resume, and it keeps doing this until I disconnect it.
during all this, my low beams flash like mad, 5+ flashes every second, and once the alarm is disabled by unlocking the car it will resume the flashing without alarm. key in seems to solve it and turning the key to position 2 shows no abnormal behavior
turning the light switch to "night mode" or turning on park lights also keeps it from happening although I haven't tried locking the car with the lights on yet

car starts and runs fine too, there is some alternator pulley whine but it's not dead yet and the battery measures 12.73v before starting.
I went on a 1hr drive earlier tonight(making sure to not shift past 3) to juice the battery up good but it doesn't seem to have helped

someone on the us tsx forums had the same issue but zero replies in the thread, so all I've got to off of right now is dying battery, failing latch sensor or... all of this in this thread and the one linked earlier. surely that wouldn't cause my low beams to switch on and off rapidly?
 
replace siren battery buddy
 
My car does this if I leave the car standing for a couple of weeks with the main battery disconnected, which causes the battery in the siren to go flat. If I reconnect the main battery and open the car door the siren goes off, but it stops after a few goes. If I sit still in the car until it stops and then move about, it goes off again. The only way for me to deal with it is to start the engine, shut the doors, and leave it for about 20 mins while the siren battery recharges.

The problem that you describe sounds similar. As well as the siren's battery being the cause, it might be the ultrasonic sensor itself that has gone faulty. But if you look at the circuit diagram below you'll see that the siren and the ultrasonic sensor both get +12V from the same feed, and since the sensor doesn't have a battery in it, the battery in the siren might be low enough to cause it to mis-read the line from the ultrasonic sensor.

SEA3E00000000000000EBAT00i014.jpg



IMO it's best to get to the siren and take it out and check the internal battery pack, as in #25.
Thanks for the reply Brian. What you say seems to add up. I left the car standing for a week last week, and when I came to start the car, the battery was totally dead - which indicates a dodgy battery. When I went home last night the siren went off. I set off for home expecting the siren to sound again, but it didn't, and today it's behaving itself, so maybe it's charged itself. Still a bit confused as to why the ultra sonics set the alarm off though. I'll wait and see what happens.
 
Hi freddofrog can you give me a few hints or pics to help with removal of the carpet trim to access the siren.
Ed R.
 
Thanks for all these posts, reading them is making my alarm problem make more sense, as above my alarm is still armed as the key fob has stopped working, I've replaced the batteries in both fobs ***uming that would be the solution, however they still don't work, could 2 batteries new in the pack be faulty? When you press the buttons on both fobs neither of them shows the red led light that indicates they are working, I've tried to reprogram them to the car so am now wandering if I just need to replace them to unarm the system, thinking about it, there were no signs of the battety in the key fob running low, one minute it was working fine and the next - nothing, so had to unlock the drivers door manually setting off the alarm, 2 weeks later and I am still driving around with a cereal box covering the internal sensors and only being able to open the drivers door without setting off the alarm, great getting kids in and out - do I just buy another key and swap the inside into my key? Will that work or is the chip programmed to the circuit board in each individual key?
 
Old thread but really really useful. Just removed lining from boot on my CL9 2.4 accord saloon to replace battery pack in siren. Followed these instructions through the thread which make it really easy. Ordered new pack through Cellsolutions.co.uk
They are building the pack tomorrow and will post in the afternoon. Hopefully ending months of wire and circuit testing. Cheers lads for the clear "how to" instructions
 
Hi Steve, I had same issues and went to the trouble of getting the alarm battery.... £20..but have not fitted it yet as i dont want to have to strip out all the carpet and trim in the boot... Just yet..... What I have done is disabled the alarm by disconnecting the bonnet contact wire behind the front grill... Fiddly but not too difficult....then insert a wire link into the connector on the wiring harness... This tells the alarm that the bonnet is open, when in fact it is closed.... and stops the alarm from arming. Then when you give the car a good run... I did it while going away for weekend to cumbria... Before lockdown.... And it recharged alarm battery and all is well. Central locking and deadlocking works but alarm doesn't arm... So no siren going off.... But no flashing indicators to let you know it is central locking... But you can see and hear it is locking if nearby. I never ever had the alarm siren go off while it was working.... and if it did nobody ever showed any interest.... It was just a audible warning.... And finally a random nuisance..... Nobody wants to steal an old honda accord..... and if you deadlock it every time they can't open the doors.... And no way can they open the bonnet either...or bypass the immobiliser.... . It is almost impossible to open the bonnet to access the ecu.... If the release cable fails it's a nightmare for garage mechanics anyway so thieves won't get it open.
So I exist without the alarm.... At the moment and unless you leave the car unused for too long the alarm box will top up its charge and the central locking continues to work as it should.
Ed
 
Hi Steve, I had same issues and went to the trouble of getting the alarm battery.... £20..but have not fitted it yet as i dont want to have to strip out all the carpet and trim in the boot... Just yet..... What I have done is disabled the alarm by disconnecting the bonnet contact wire behind the front grill... Fiddly but not too difficult....then insert a wire link into the connector on the wiring harness... This tells the alarm that the bonnet is open, when in fact it is closed.... and stops the alarm from arming. Then when you give the car a good run... I did it while going away for weekend to cumbria... Before lockdown.... And it recharged alarm battery and all is well. Central locking and deadlocking works but alarm doesn't arm... So no siren going off.... But no flashing indicators to let you know it is central locking... But you can see and hear it is locking if nearby. I never ever had the alarm siren go off while it was working.... and if it did nobody ever showed any interest.... It was just a audible warning.... And finally a random nuisance..... Nobody wants to steal an old honda accord..... and if you deadlock it every time they can't open the doors.... And no way can they open the bonnet either...or bypass the immobiliser.... . It is almost impossible to open the bonnet to access the ecu.... If the release cable fails it's a nightmare for garage mechanics anyway so thieves won't get it open.
So I exist without the alarm.... At the moment and unless you leave the car unused for too long the alarm box will top up its charge and the central locking continues to work as it should.
Ed
Ed
Sounds like you had more of a faff getting to the wire to disconnect the switch than you would of lifting the boot carpet and unclipping the right hand boot liner. Just taken siren out of my doner Cl9 and it was a doddle 1 x 10mm spanner was all it took and a #2 Phillips to get siren open to access the battery. Phoned cell solutions placed order £12 including postage and they will get on with making them tomorrow. Coming from South shields so should be here Saturday let us know if this fixes your problem, I will do the same
 
Ed
Sounds like you had more of a faff getting to the wire to disconnect the switch than you would of lifting the boot carpet and unclipping the right hand boot liner. Just taken siren out of my doner Cl9 and it was a doddle 1 x 10mm spanner was all it took and a #2 Phillips to get siren open to access the battery. Phoned cell solutions placed order £12 including postage and they will get on with making them tomorrow. Coming from South shields so should be here Saturday let us know if this fixes your problem, I will do the same
Hi scottydog... It took no more than 10-15mins to access plug and link it
I dont know what vehicle you are referred too.... Mine is a Honda Accord tourer and removing floor carpet and side trim is a bit of a FAFF, and breaking lugs and fixings are likely if you are not familiar with the removal... But please do it your own way.... Mine works for me and although the flashing indicators were handy.... I prefer my central locking etc working and no nuisance alarms in the dead of night.
 
Hi scottydog... It took no more than 10-15mins to access plug and link it
I dont know what vehicle you are referred too.... Mine is a Honda Accord tourer and removing floor carpet and side trim is a bit of a FAFF, and breaking lugs and fixings are likely if you are not familiar with the removal... But please do it your own way.... Mine works for me and although the flashing indicators were handy.... I prefer my central locking etc working and no nuisance alarms in the dead of night.
Ed. I was referring to the saloon. That took longer to get the tools from the shed than it did to access and remove the siren and find company to place battery order. Would have thought the tourer would have been designed to be as easy. We just need to do what works for us.
 
Sure do. May eventually resort to fitted battery in siren box but for now am happy with it as it is and my alarm battery is seemingly holding charge....accessing siren in estate seems to be a bit of a job and not worth the trouble yet.... I can reinstate the bonnet contact easily enough if needed.
 
Old thread but really really useful. Just removed lining from boot on my CL9 2.4 accord saloon to replace battery pack in siren. Followed these instructions through the thread which make it really easy. Ordered new pack through Cellsolutions.co.uk
They are building the pack tomorrow and will post in the afternoon. Hopefully ending months of wire and circuit testing. Cheers lads for the clear "how to" instructions
I planned to replace battery pack in siren, supposedly in rear offside quarter of tourer, obtained battery pack, stripped rear trim etc out of boot and no siren module to be found. As i had disabled the alarm to prevent spurious alarms by removing the bonnet plug from bonnet catch and inserting a shorting link to simulate an open bonnet and disabling the alarm function, I decided to rrmove the link to set the alarm and trigger it so I could find the siren and it was down the front of the car in the space behind the headlight on the nearside, in the space where the bonnet catch lives. It is not the one shown in the links on the forum, the Cobra one with the electronics includes with the siren, it is just a siren.... So where are the electronics and maybe the backup battery? I am finding that my main battrry may be being duscharged by having the s/c on the bonnet catch wiring.... as in normal use it is o/c when the bonnet is closed and goes S/c when a door or bonnet opens but usually is cleared when the bonnet or door is closed.... And in my case it is always s/c and i think it is pulling my new battery down over a period of inactivity... Due to CV19 inactivity. So can any of you guys suggest where the control module may be.... As it isnt where the Cobra one should be... ie in the boot on the drivers side.... There is nothing but my speaker in that location. However there is a small plastic box in the other side, attached to the bodywork with sticky back foam tape.... Maybe it is the alarm electronics.... Any ideas most welcome. Ed R
 
Hi Ed,
You may have a non aftermarket system some pics would help identify
 
Hi Ed,
You may have a non aftermarket system some pics would help identify
Hi Ed,
You may have a non aftermarket system some pics would help identify
Thanks for getting back quickly.... The pic of the siren is like the used ones on ebay as Honda Accord 2003-7 alarm horn/siren and sells at £10-20 and has one fixing strap and apparently according to the ebay ad had only 1wire connection.... So it must not be the home of the electronics and backup battery. I am going to check shortly if the siren/horn i found is the car horn and is multi tasking....I now also have the battery pack for the Cobra alarm... Cost £25 but will probably not need it now... Could pass it on at a modest price if I find it isnt required
 
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Some systems use the horn as siren as well, keep us posted you could possibly sell on this forum.
 
Some systems use the horn as siren as well, keep us posted you could possibly sell on this forum.
Have just tested horn and it is a two tone horn... And seem to be from other side of front... Will look tomorrow to see if the siren is one tone and a second one on other side is the other tone.... If not I can disconnect the siren and reconnect the bonnet wiring. I may have a bluetooth Hands free issue draining main battery... As I don't use it as it is unreliable.... Can disconnect it if siren is separate and then get rid if s/c on sensor wire and maybe clear main battery drain and reinstate siren.
 
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