Mazda 6 Car Alarm keeps going off! Help! :)

Paul_RD said:
There is a "Liftgate Latch Position Switch" positioned somewhere near/on the boot lock.
It has four switches within it.
All four switches are connected to the "Liftgate Auto Closure Control Module"
One of those switches also feeds both the "BCM" and the "Cargo Compartment Light"
BCM then feeds the "Theft-Deterrent System".

  • Something you could try:
    • Remove the rear parcel shelf.
    • Verify that the boot light is on.
    • Shut the tailgate gently.
    • Verify that the boot light goes out.
    • Bounce the vehicle / push down on the tailgate - does the boot light come on / flicker?
  • Try the above again, this time closing the tailgate with a slam - same result?
Click to expand...

Thank you so much for the help. I'm going to have a mess before it goes dark :)
 
Paul_RD said:
There is a "Liftgate Latch Position Switch" positioned somewhere near/on the boot lock.
It has four switches within it.
All four switches are connected to the "Liftgate Auto Closure Control Module"
One of those switches also feeds both the "BCM" and the "Cargo Compartment Light"
BCM then feeds the "Theft-Deterrent System".

  • Something you could try:
    • Remove the rear parcel shelf.
    • Verify that the boot light is on.
    • Shut the tailgate gently.
    • Verify that the boot light goes out.
    • Bounce the vehicle / push down on the tailgate - does the boot light come on / flicker?
  • Try the above again, this time closing the tailgate with a slam - same result?
Click to expand...

Yep, same result indeed! No matter how lightly or hard I close the boot, the boot light does go out, and no matter how much I sit in the back and try to jump/move, it doesn't flicker or anything like that. I don't know if this gives more likelihood to the issue being the boot opening button that sits in the tailgate brake light. I've seen that I can get a replacement for the whole rear tailgate brake light for about £20 too.
 
bobert50 said:
Yep, same result indeed! No matter how lightly or hard I close the boot, the boot light does go out, and no matter how much I sit in the back and try to jump/move, it doesn't flicker or anything like that. I don't know if this gives more likelihood to the issue being the boot opening button that sits in the tailgate brake light. I've seen that I can get a replacement for the whole rear tailgate brake light for about £20 too.
Click to expand...

You should be able to unplug the opening button and see if that cures your problem, assuming that you can open the boot from the remote key or some other means.
 
bobert50 said:
Yep, same result indeed! No matter how lightly or hard I close the boot, the boot light does go out, and no matter how much I sit in the back and try to jump/move, it doesn't flicker or anything like that. I don't know if this gives more likelihood to the issue being the boot opening button that sits in the tailgate brake light. I've seen that I can get a replacement for the whole rear tailgate brake light for about £20 too.
Click to expand...
There are four switches within the "Liftgate Latch Position Switch" assembly that are connected to the "Liftgate Auto Closure Control Module".
All four switches feed the "BCM".
But, only one of those four switches feeds both the "BCM" and the "Cargo Compartment Light" - that is the one I was trying to get you to test.
The other three you cannot test easily and they will require interrogating the "BCM" with a diagnostic reader.
 
Silent Bob said:
Another common fault is the rubber boot button perishing and water getting in. This can cause the button to go a bit haywire. I’d check that out first before replacing the locking mechanism.
Click to expand...
this

bobert50 said:
It really does seem more prone when it is very hot/sunny. It seems to just not do it when the weather is cold/rainy.
Click to expand...

when its wet the moisture may lube the switch and it works correctly ...and breaks when dry.
dismantling the switch, if possible, and use switch cleaner, I usually spray servisol 10, not wd40, through the smallest openings,
often the plastic welded switch bodies can be pried open, drop of superglue to re-seal.

moreover- does alarm go off if you do try the switch on a parked/alarmed car ? that should be an indication if the switch could be the problem.
 
Hi guys,

I just wanted to do another update. I was debating over the weekend what was the best way to go and based on the fact I've got fairly limited spare time to fiddle and the fact that it really could do with being sorted asap... I've opted to buy a boot lock mechanism and a replacement tailgate/third brake light with the boot button/bits attached from a scrapyard for relative peanuts.

I'm going to hopefully get them fitted towards the middle or end of this week and then going to keep my fingers crossed that it fixes the problem. With all this rain though at the moment, i doubt i'll even know for a while either way. I'll need the sun to come out... perhaps next year! :D

Thank you for the help guys. I'll do an update when i know for sure just in case anybody looks at this thread down the line and wants to know how it went or finds it in a future search.
 
bobert50 said:
Hi guys,

I just wanted to do another update. I was debating over the weekend what was the best way to go and based on the fact I've got fairly limited spare time to fiddle and the fact that it really could do with being sorted asap... I've opted to buy a boot lock mechanism and a replacement tailgate/third brake light with the boot button/bits attached from a scrapyard for relative peanuts.

I'm going to hopefully get them fitted towards the middle or end of this week and then going to keep my fingers crossed that it fixes the problem. With all this rain though at the moment, i doubt i'll even know for a while either way. I'll need the sun to come out... perhaps next year! :D

Thank you for the help guys. I'll do an update when i know for sure just in case anybody looks at this thread down the line and wants to know how it went or finds it in a future search.
Click to expand...
Good luck with it and with the weather.
Mines on jacks at the moment - both bottom ball-joints (comes as a complete lower control arm for £££ - bought yesterday) and drivers side CV boot (previous owner had an after-market drive shaft fitted so Genuine Mazda boots don't fit - trying to source a universal boot that fits).
I've just got to sort out the CV boot and hope for some nice weather as well.
 
Update - Had the new boot lock mechanism and third rear brake light containing the boot button/chip yesterday... and the alarm just went off again 10 mins ago :(

I'll have to take it back to the garage on Monday I think or whenever they can next see me and see what their machine is indicating the issue is now, but i'm leaning more and more towards trying to get the alarm just removed/unplugged.
 
There’s a fair chance that the alarm is integral to the car and not removable.

Depending on the year, having the alarm will have been a part of its type approval.
 
It might be OK. I've seen on forums that people have just removed the black alarm box from a 2008 Mazda and a 2010 one. Mine is a 2010 one. I'm really hoping i can if it really does come to it... could do without this issue costing much more money.
 
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bobert50 said:
It might be OK. I've seen on forums that people have just removed the black alarm box from a 2008 Mazda and a 2010 one. Mine is a 2010 one. I'm really hoping i can if it really does come to it... could do without this issue costing much more money.
Click to expand...
The alarm on my 2008 Mazda 6 (GH version - same as yours) goes off with hazard lights only, but no alarm noise.
I decided to investigate the sounder (out of interest) and it turned out it was actually connected (I suspected it may have been disconnected previously).
As an experiment, I disconnected the alarm sounder and it seemed to make no difference to anything whatsoever - the vehicle still locked/unlocked/started.
I would suggest that it's worth a try to disconnect your own sounder - it's located behind the trim on the right hand side of the boot (exactly opposite the fuel filler cap).
(Be aware - if your sounder is serviceable, it may go off when you disconnect it thinking it's being tampered with - in that case stuff a load of rags around it to muffle the noise until the internal battery goes flat)
Worst case, it wont start :( - best case, it won't make a noise :D
 
Paul the saviour returns! :D phew!

Ah funny you should say that as I believe I saw a short one minute video of this on YouTube earlier. Perhaps a daft question but is it easy to pull this trim on the right side of the boot back if it hasn't been messed with previously?
 
bobert50 said:
Paul the saviour returns! :D phew!

Ah funny you should say that as I believe I saw a short one minute video of this on YouTube earlier. Perhaps a daft question but is it easy to pull this trim on the right side of the boot back if it hasn't been messed with previously?
Click to expand...

It's a bit awkward - this is what I did to get access:
  • Fold the rear right seat forward.
  • Remove the boot carpet.
  • Remove the black polystyrene finisher from above the jack.
  • Inside the boot, remove the two right hand cargo net anchor points (one at the front and one at the rear).
  • There are also some plastic clips you will have to remove (at both the front and rear).
  • Pull the rear right hand trim out at the lower and rear edges and eventually you should have enough access to see the alarm sounder and get your hand in by reaching in from the rear.
  • The alarm sounder is mounted behind a metal support and is difficult to get to.
  • However, there is a short cable (three inches approx) coming out of the alarm sounder which connects to the wiring loom via a 3-pin connector which is easy to see and disconnect.
Have a look at the following video on YouTube (and read the comments):


​
 
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Hi Paul, thank you so much again. I got to read it but couldn't reply until now... to say work is busy would be an understatement at the moment! :o

Brilliant. Yep that is the video i'd seen but i wasn't sure if it was the MK2 that we both have, but it certainly looks like it.

I'm going to shortly have a look for this 10 mil bolt that he speaks of on the video!

https://imgur.com/a/iNdZLfV

Starting point above... I'm going to have a mess with your instructions above in the next few hours and see how I get on. Hopefully the trim goes on properly again afterwards! My partner wants me to wait until the alarm goes off at least once more but I really want this crap permanently sorted, to be honest!
 
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