2017~2021 Rear hatch opening by itself?

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2013 Mazda CX-5 Sport FWD Auto
I accidentally set off the panic alarm on my ‘13 Sport on a near weekly basis at work. Didn’t take much with the key fob in my pocket. Did it from a hell of a distance too. Couple hundred feet through my office wall to the parking garage outside.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
My 2019 CX5 is doing the same thing for some reasons. It happened probably 3-4x already. At first I thought it accidentally left open or FOB issue but the latest incident has convinced me its not negligence issue. Something that triggers the opening.

This is my 6th Mazda and 3rd CX5 and this is the first time I'm having this issue.

This is my first post in a long time and the reason I'm here is to check for similar incident with other owners.
The best chance to get your mysterious problem fixed is to take your CX-5 to your Mazda dealer. If they can’t help you, you escalate this issue to Mazda North American Operations and create a case. Tell them it’s a safety issue and ask them to find out if there’s a solution yet with a Service Alert or Technical Service Bulletin.
 
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CX5
I suspect that the number of times that this has happened is tiny and is either due to user error or someone locally transmitting on the same frequency. I don't know where these fobs are in the frequency range, but I'll bet they're close to other devices.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
It is kind of mysterious. There are some rear hatch modules that cause a run down battery. I wonder if there is something wrong with this module?
 
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CX5
I guess if those experiencing this issue have a VIN number in this range...JM3KFxxxxxx700008-820235 produced from September 13, 2019 through March 18, 2020, then that might be a factor. There's so much RF flying around though, my guess would still be something transmitting on the same frequency.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I guess if those experiencing this issue have a VIN number in this range...JM3KFxxxxxx700008-820235 produced from September 13, 2019 through March 18, 2020, then that might be a factor. There's so much RF flying around though, my guess would still be something transmitting on the same frequency.
Mazda’s remote key fob for CX-5 has FCC ID WAZSKE13D01 which uses 315 MHz. Usually this frequency is reserved by this FCC ID and the possibility of interference by other device is minimum. The control module should handle unintended signals and only take actions with legit signals transmitted by the key fob. If the unintended signals from an unknown device with 315 MHz nearby, it should trigger not only the power liftgate, but also the door locks and even the alarm. Just by this reason the culprit has to be the firmware bugs in the power liftgate control module.
 
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CX5
I doubt that. You'd be looking at thousands of complaints. I don't think that the Mazda dealerships are even aware of this issue.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
I had an aunt back in the 1980s whose garage door started opening by itself. It was very mysterious. They figured out it was jets flying overhead that used a similar frequency.
Modern garage door openers use specially coded signals and can't be opened with random radio signals. I doubt you can spring a car door (or hatch) just by using the same frequency.
 
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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I had an aunt back in the 1980s whose garage door started opening by itself. I was very mysterious. They figured out it was jets flying overhead that used a similar frequency.
Modern garage door openers use specially coded signals and can't be opened with random radio signals. I doubt you can spring a car door (or hatch) just by using the same frequency.
Definitely you can’t just receive a 315 MHz signal and react to it. There’s a decoding algorithm built in the firmware. Software will always have some bugs and this’s a case that power liftgate control module is mishandling some unintended random 315 MHz signals and mistakenly sends a command to open the liftgate. Of course this won’t happen frequently, but only all situations come at the same time and meet the criteria.
 
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CX5
The only other thing I can think of would be the latching mechanism not closing correctly, even though it appeared to. It would be interesting to know if those having this issue had unloaded from the cargo area and then closed the hatch, and then had this problem. It could be a latch assembly issue.
 

Zmud

Old and OCD
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2019 cx5 2006 mx5
FWIW, I was in my garage stooping to mix paint, had the fob in my pocket. The rear hatch opened.

I think it's easier to actuate than you would suspect.
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
They ought to protect those buttons. It would help me if the lock and unlock buttons were further apart or somehow easier to identify by feel.
 
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GA prior 16 CX5 GT
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20 CX5 GT + Prem
How many of you have accidentally bumped the panic button and had the horn go off? It is the same as the trunk opening.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
How many of you have accidentally bumped the panic button and had the horn go off? It is the same as the trunk opening.
Never! So as the trunk release (not a power lifter) on my 1998 Honda CR-V!
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
They ought to protect those buttons. It would help me if the lock and unlock buttons were further apart or somehow easier to identify by feel.
Agreed. See how my Honda key fob is protecting unlock, trunk-release and panic buttons with a different shape and size too.

2018-mazda-cx-5-intelligent-smart-key-remote-w-hatch-11.jpg


honda_new_dealer_installed_honda_cr_v_crv_97_98_99_00_01_2001_2000_1998_1999_1997_a269zua101_k...jpg
 

Davidiot

Ballistic Reentry Vehicle
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2020 CX-5 GT PP
I street park in a very busy area. I often can’t see my car from my house (I live above a main-street business and can’t park immediately in front) but my fob apparently can still reach my out-of-sight car. This issue hasn’t happened to me yet but it is freaking me the Hell out.

If I could disable remote hatch opening, I would do it in a heartbeat.

(I’ve never used the fob to open my hatch in the month I’ve owned the car, anyway.)
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
I street park in a very busy area. I often can’t see my car from my house (I live above a main-street business and can’t park immediately in front) but my fob apparently can still reach my out-of-sight car. This issue hasn’t happened to me yet but it is freaking me the Hell out.

If I could disable remote hatch opening, I would do it in a heartbeat.

(I’ve never used the fob to open my hatch in the month I’ve owned the car, anyway.)
https://www.amazon.com/s?k=Faraday+Box&ref=nb_sb_noss_2&tag=m20b7-20?tag=m20b7-20

You could keep your fobs in a faraday box or bag/pouch when you're home or at work to block the fob from sending unintended signals to the car.

For users experiencing this problem, you can determine whether the problem is fob-related by placing your key fob in a faraday pouch right after you lock the vehicle. If you no longer come back to a car with the hatch open over a long enough period of time, you can safely assume that the problem is fob-related. If the hatch continues to open on it's own while the fob is secured in a faraday pouch/box, it's likely a problem with the car itself (BCM, power liftgate module) or RF cross-transmission (or possibly a latching mechanism issue as TDK1044 mentioned).
 

Davidiot

Ballistic Reentry Vehicle
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2020 CX-5 GT PP
https://www.amazon.com/s?k=Faraday+Box&ref=nb_sb_noss_2&tag=m20b7-20?tag=m20b7-20

You could keep your fobs in a faraday box or bag/pouch when you're home or at work to block the fob from sending unintended signals to the car.

For users experiencing this problem, you can determine whether the problem is fob-related by placing your key fob in a faraday pouch right after you lock the vehicle. If you no longer come back to a car with the hatch open over a long enough period of time, you can safely assume that the problem is fob-related. If the hatch continues to open on it's own while the fob is secured in a faraday pouch/box, it's likely a problem with the car itself (BCM, power liftgate module) or RF cross-transmission (or possibly a latching mechanism issue as TDK1044 mentioned).
Understood, but I haven’t experienced the problem, (yet, knock-wood), and blocking the signals altogether is not what I would want anyway.

I LOVE being able to walk up to my locked car with my keys in my pocket and just open the doors. Even better, not bothering to lock the doors as I walk away, and have the car do that (AND fold in the mirrors) automatically on its own.
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
Understood, but I haven’t experienced the problem, (yet, knock-wood), and blocking the signals altogether is not what I would want anyway.

I LOVE being able to walk up to my locked car with my keys in my pocket and just open the doors. Even better, not bothering to lock the doors as I walk away, and have the car do that (AND fold in the mirrors) automatically on its own.
I know you haven't experienced the problem yet, but you have expressed concern about the potential for this issue and expressed interest in a way to prevent it from happening.

As I said, you could keep your fobs in a faraday box or bag/pouch when you're home or at work to prevent the fob from accidentally sending signals to the car. Specifically, when you come home, instead of tossing the keys in a bowl or hanging them on a key rack, you put them in the faraday box/pouch. When you leave, you take the keys out and use them as you would normally (i.e. keep them in your pocket).

When you're at work, you'd store the keys in a faraday box/pouch in your locker/backpack/desk, and take them out before you leave. The faraday box/pouch basically eliminates user/fob error by blocking the signal sent out by the fob.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Even better, not bothering to lock the doors as I walk away, and have the car do that (AND fold in the mirrors) automatically on its own.

There’re reports and based on my own experience this auto-locking feature on the CX-5 won’t happen 100% of time which may leave us in an undesired situation with unlocked vehicle. I have to pay attention making sure I hear the first beep, otherwise I take my key fob out and lock the CX-5 “manually”.

With auto-folding mirrors, that should be easier to verify if the CX-5 is auto-locked or not.
 
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