F31 'key' issue

Pond · 03-14-2024, 03:59 PM

My F31 (2016) keeps deciding that the key is not 'in range' or 'key is missing' when you go to start it.
I thought it was just my key needing a new battery but the spare key (the wife's) has been doing the same thing. I have an invoice for 2 new batteries for the keys when I bought the car in January, so doubt it is batteries.

The strange thing is that the car always unlocks with either remote from quite a distance and only decides the key isn't present sometimes, not always. I keep the key/remote in the same pocket always.

Any ideas?

BTW car doesn't have comfort access just keyless start (or not).

Alscoob · 03-15-2024, 05:22 AM

My old F31 would do that & (I'll check) but think my 540 does it too.

You could lock / unlock from a distance but unless the key was physically in the car it would not start, it would say key not present, even if it was in your hand on an semi open door like you were going to start it without getting in the car.

SkyJawa · 03-15-2024, 06:51 AM

I'm gonna be the one that says it

Any fault codes stored?

NanasBack · 03-15-2024, 08:15 AM

My F30 did something similar last year.
Changing the keyfob battery did fix it.

CR2450 are around 2 for £4 and easy to replace.

Got to be worth a punt as you don't know how old the 'new' batteries were when they were fitted.

C320 · 03-15-2024, 10:02 AM

Quote:

Originally Posted by Pond

My F31 (2016) keeps deciding that the key is not 'in range' or 'key is missing' when you go to start it.
I thought it was just my key needing a new battery but the spare key (the wife's) has been doing the same thing. I have an invoice for 2 new batteries for the keys when I bought the car in January, so doubt it is batteries.

The strange thing is that the car always unlocks with either remote from quite a distance and only decides the key isn't present sometimes, not always. I keep the key/remote in the same pocket always.

Any ideas?

BTW car doesn't have comfort access just keyless start (or not).

Does it still start, despite the message being displayed?

Not a BMW, but in our XC90 we had an aftermarket wireless charging unit and that interfered with the key signal so we'd constantly get 'key missing' warnings on that.

A google search suggested wireless chargers could be the cause so I removed it and it's been fine ever since!

Pond · 03-15-2024, 11:02 AM

No fault codes. No aftermarket stuff in the car.
If you hold the key to the steering wheel when the issue comes up it's OK. It only does it sometimes, not every start.

I have a sneaky feeling it is associated with a slightly low car battery not the keys themselves.
I am guessing but a slightly low battery voltage could reduce the immobiliser's receiver strength.

The car isn't used all the time and seems to do it after being stood a while or after a very short journey. I usually keep car batteries charged regularly but it hasn't stopped raining for weeks so has been a bit neglected as this one stays outside.

We all know BMWs don't like anything but a really healthy battery, as they can have all manner of 'hissy fits' if the voltage isn't 100%.

when we finally get a day without rain, I will stick the cTek on and see if that cures it.

Alscoob · 03-15-2024, 12:30 PM

Quote:

Originally Posted by Pond

No fault codes. No aftermarket stuff in the car.
If you hold the key to the steering wheel when the issue comes up it's OK. It only does it sometimes, not every start.

I have a sneaky feeling it is associated with a slightly low car battery not the keys themselves.
I am guessing but a slightly low battery voltage could reduce the immobiliser's receiver strength.

The car isn't used all the time and seems to do it after being stood a while or after a very short journey. I usually keep car batteries charged regularly but it hasn't stopped raining for weeks so has been a bit neglected as this one stays outside.

We all know BMWs don't like anything but a really healthy battery, as they can have all manner of 'hissy fits' if the voltage isn't 100%.

when we finally get a day without rain, I will stick the cTek on and see if that cures it.

Seems like you've just answered your own question

oh and get a waterproof coat..

Pond · 03-15-2024, 12:38 PM

Quote:

Originally Posted by Alscoob

Seems like you've just answered your own question

Depends whether my theory is correct I suppose.

Alscoob · 03-16-2024, 05:28 AM

Quote:

Originally Posted by Pond

Depends whether my theory is correct I suppose.

Only one way to find out......

03-14-2024, 03:59 PM	#1
Pond Lieutenant Colonel 1838 Rep 1,706 Posts Drives: E89 Z4, F31 and Z3 project Join Date: Sep 2021 Location: Lincs UK iTrader: (0)	F31 'key' issue My F31 (2016) keeps deciding that the key is not 'in range' or 'key is missing' when you go to start it. I thought it was just my key needing a new battery but the spare key (the wife's) has been doing the same thing. I have an invoice for 2 new batteries for the keys when I bought the car in January, so doubt it is batteries. The strange thing is that the car always unlocks with either remote from quite a distance and only decides the key isn't present sometimes, not always. I keep the key/remote in the same pocket always. Any ideas? BTW car doesn't have comfort access just keyless start (or not).
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03-15-2024, 05:22 AM	#2
Alscoob Brigadier General 2119 Rep 3,066 Posts Drives: G31 540i M Sport Edition Join Date: Jun 2015 Location: UK iTrader: (0)	My old F31 would do that & (I'll check) but think my 540 does it too. You could lock / unlock from a distance but unless the key was physically in the car it would not start, it would say key not present, even if it was in your hand on an semi open door like you were going to start it without getting in the car.
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03-15-2024, 06:51 AM	#3
SkyJawa Major General 3719 Rep 8,636 Posts Drives: F10 530d Join Date: May 2014 Location: Hampshire iTrader: (1)	I'm gonna be the one that says it Any fault codes stored?
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03-15-2024, 08:15 AM	#4
NanasBack Lieutenant 200 Rep 542 Posts Drives: EB 335 oil burner Join Date: Aug 2017 Location: Staffs, UK iTrader: (0)	My F30 did something similar last year. Changing the keyfob battery did fix it. CR2450 are around 2 for £4 and easy to replace. Got to be worth a punt as you don't know how old the 'new' batteries were when they were fitted. __________________ 335d xDrive
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03-15-2024, 11:02 AM	#6
Pond Lieutenant Colonel 1838 Rep 1,706 Posts Drives: E89 Z4, F31 and Z3 project Join Date: Sep 2021 Location: Lincs UK iTrader: (0)	No fault codes. No aftermarket stuff in the car. If you hold the key to the steering wheel when the issue comes up it's OK. It only does it sometimes, not every start. I have a sneaky feeling it is associated with a slightly low car battery not the keys themselves. I am guessing but a slightly low battery voltage could reduce the immobiliser's receiver strength. The car isn't used all the time and seems to do it after being stood a while or after a very short journey. I usually keep car batteries charged regularly but it hasn't stopped raining for weeks so has been a bit neglected as this one stays outside. We all know BMWs don't like anything but a really healthy battery, as they can have all manner of 'hissy fits' if the voltage isn't 100%. when we finally get a day without rain, I will stick the cTek on and see if that cures it.
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