Key fob low battery on dash but new batteries?

[Richmond]

I have a 2018 CX-5 and the low battery key fob warning comes up on the dash even with new batteries in them.

 

[wlong01]

Try another battery.

 

[Richmond]

I’ve tried four batteries and not cheap ones in four months I’ve tried the ones I’ve taken out on a amp meter they have over 3 vaults in them thank you

 

[Richmond]

Thanks for letting me join

 

[Sig cx-5]

How old are the batteries you're using? Do both your fobs show the same message?

 

[Richmond]

Both fobs say low battery or key not recognised batteries have 2025 date on them

 

[RedBaron]

Both fobs say low battery or key not recognised batteries have 2025 date on them

I know you said you checked them, but even so, new batteries should have at least a 10 year in the future date (i.e. > 2032). The fact that yours have 2025 leads me to think "old stock".

 

[Richmond]

I’ll try that thank you

 

[7eregrine]

2032 and 2025 are not the date. These batteries are not dated.
That is the model, basically, of the lithium battery.

CR2025 is used in the newer key fobs. CR2032 is used in the older key fobs.

 

[Richmond]

I know on packing says 2025 thanks

 

[ceric]

20 -> diameter in 1mm.
25/32 -> thickness in 0.1mm

2032: a button battery that is 20mm/2cm in diameter and 3.2mm thick.

 

[wlong01]

Try holding the FOB right up to the start button. If the low battery indicator does not come on then it's more than likely the battery. Where is the FOB when you start the car? Sometimes if mine is deep in my pants I'll get the low battery indicator.
If my wife has hers in her pocketbook down on the floor she'll get the msg.

 

[HyFlyer]

On my 2019 Signature, my "replace key fob battery" message has displayed ever since basically new. Both fobs. Changed to new fob batt 1.5 years later (with no issues during that time) and still have the same message with no actual problems though. I just ignore it. Seems to be a "glitch in the system."

 

[GAXIBM]

Not sure about 18s but on 2020 the keyfob can go to low power mode and it will unlock the car with the button but not activate the on off switch unless you touch the switch. Check your manual, can not remember how to reset it

 

[Ranman57]

I'll bet you left the key in the car or close enough to activate the power save feature. The same thing happened to my extra fob and this solved the issue. I swapped the battery to no avail then remembered seeing this somewhere in the manual.

Turning off the power saving function

After you have turned off the power saving function according to the following
procedure, the hazard warning lights and sound operate*1 one time.

1. Press any of the buttons on the transmitter to make sure that the operation indicator light does not turn on/flash.

2. Press the lock button on the transmitter 4 times within 3 seconds to turn on the operation indicator light.

3. Press the lock button continuously for1.5 seconds or longer while the
operation indicator light turns on (for 5seconds).

 

[Richmond]

I'll bet you left the key in the car or close enough to activate the power save feature. The same thing happened to my extra fob and this solved the issue. I swapped the battery to no avail then remembered seeing this somewhere in the manual.

Turning off the power saving function

After you have turned off the power saving function according to the following
procedure, the hazard warning lights and sound operate*1 one time.

1. Press any of the buttons on the transmitter to make sure that the operation indicator light does not turn on/flash.

2. Press the lock button on the transmitter 4 times within 3 seconds to turn on the operation indicator light.

3. Press the lock button continuously for1.5 seconds or longer while the
operation indicator light turns on (for 5seconds).

Thanks, I’ll try that.

 

[sgow0204]

Mazda Key Fob Low Battery Issue

It means it has gone into the power saving mode. Usually when the old battery is about to die, the Fob turns on the Power Saving mode itself. So, from there on you need to get the fob so close to the ignition button to start engine + your keyless entry won’t work.
So, after you change your old batteries and put a new battery, the fob will continue to be in the Power Saving Mode. There are simple steps to take the Fob out of Power Saving mode.

1. Turn on the Engine
2. Use your fob and press your “Lock” button 4 times
3. You’ll see the indicator (red light) on your fob light up
4. Immediately after you see the red light on your fob, press and hold “Lock” button until you see your indicator lamps (green) on your car dashboard flash a couple of times. This means you have toggled the POWER SAVE MODE.
5. Try your keyless entry and try turning on ignition with the keys in your pocket -

This should work

 

[Richmond]

I'll bet you left the key in the car or close enough to activate the power save feature. The same thing happened to my extra fob and this solved the issue. I swapped the battery to no avail then remembered seeing this somewhere in the manual.

Turning off the power saving function

After you have turned off the power saving function according to the following
procedure, the hazard warning lights and sound operate*1 one time.

1. Press any of the buttons on the transmitter to make sure that the operation indicator light does not turn on/flash.

2. Press the lock button on the transmitter 4 times within 3 seconds to turn on the operation indicator light.

3. Press the lock button continuously for1.5 seconds or longer while the
operation indicator light turns on (for 5seconds).

I have taken my cx5 into Mazda they can’t find anything wrong with the car or fobs the fitter put two new varta batteries in which apparently are slightly thicker never had a problem since

 

[Conrad 16.5]

Mazda Key Fob Low Battery Issue

It means it has gone into the power saving mode. Usually when the old battery is about to die, the Fob turns on the Power Saving mode itself. So, from there on you need to get the fob so close to the ignition button to start engine + your keyless entry won’t work.
So, after you change your old batteries and put a new battery, the fob will continue to be in the Power Saving Mode. There are simple steps to take the Fob out of Power Saving mode.

1. Turn on the Engine
2. Use your fob and press your “Lock” button 4 times
3. You’ll see the indicator (red light) on your fob light up
4. Immediately after you see the red light on your fob, press and hold “Lock” button until you see your indicator lamps (green) on your car dashboard flash a couple of times. This means you have toggled the POWER SAVE MODE.
5. Try your keyless entry and try turning on ignition with the keys in your pocket -

This should work

The power saving mode and having the fob not work because of a low battery are not the same thing. In fact, only newer CX-5s have this power saving mode for the fob. I don't know what year it started though. Anyone know?

 

[HyFlyer]

On my 2019 Signature, my "replace key fob battery" message has displayed ever since basically new. Both fobs. Changed to new fob batt 1.5 years later (with no issues during that time) and still have the same message with no actual problems though. I just ignore it. Seems to be a "glitch in the system."

I have taken my cx5 into Mazda they can’t find anything wrong with the car or fobs the fitter put two new varta batteries in which apparently are slightly thicker never had a problem since

An update from me on this issue ... I too have installed a 2032 size battery instead of the 2025 size battery that is specified. It's .7mm thicker (and larger power capacity) and the little cover with the o-ring gasket inside my fob doesn't fit right but the fob itself snaps closed fine.

Using a model 2032 battery instead of 2025 solved the problem for me. (For a 2019 signature)