Occasionally key is not recognized to start the engine

Krlos5411 · 04-28-2022, 07:37 PM

Hi guys, I'm new here.

Just found the forum googling abou my issue.

As the tittle said, my car somethimes gives me the issue that don't dettect my key. I need to push the start/stop engine button several times until the key is detected and the engine start.

I just replace the battery of the fob key and the problem persist.

I read in some other webs, that maybe the car battery could be low? The car hub should inform about that?

The issue is also variable with the opening and closing of the doors, so I'm assuming that the key is the issue.

I would like to check the fuses, but I couldn't find which one is the one the I need to check and if this can cause my problem.

Anyone has this problem and solved it? Any idea or suggestion?
This is my first BMW, so this issue is new to me.

This is my car

Thanks!!

richardodn · 04-29-2022, 10:14 AM

I have the same issue. Fob battery and car battery are both fairly new. I can say that it happens less often than before those were changed. I'm of the opinion that it occasionally is just a little slow reading the key. When it happens to me, I just count to 5 before trying again. That usually gives the car long enough to read the key.

mike_MAN · 04-29-2022, 12:24 PM

I had this issue and found out it was because of the rear dash cam I installed.
After I install a front and rear dash cam system, the keyless entry was working intermittently and I had to put the key up to the steering column almost all the time. The key remote only worked about 1 foot away from the car also. I brought it to the dealership and they actually replace the CAS module but it was still finicky. I unplugged the read dash cam and voila, everything works fine as it should. Don't think the CAS module had to be replaced.

I don't know if the wire I ran along the top side of the pillars were interfering with signals and sensor of if the unit itself was interfering with the sensor located at the top of the boot. For me, I was able to isolate the problem and found the error. Could be some inference issues.

Krlos5411 · 04-29-2022, 01:05 PM

Quote:

Originally Posted by mike_MAN

I had this issue and found out it was because of the rear dash cam I installed.
After I install a front and rear dash cam system, the keyless entry was working intermittently and I had to put the key up to the steering column almost all the time. The key remote only worked about 1 foot away from the car also. I brought it to the dealership and they actually replace the CAS module but it was still finicky. I unplugged the read dash cam and voila, everything works fine as it should. Don't think the CAS module had to be replaced.

I don't know if the wire I ran along the top side of the pillars were interfering with signals and sensor of if the unit itself was interfering with the sensor located at the top of the boot. For me, I was able to isolate the problem and found the error. Could be some inference issues.

I have a dashcam indeed. It is connected tho the fuse box behind the gloves box to the accessories fuse.

And as you, I also have a rear camera also wired through the left pillar

I can't recall if the issue was already before I installed the cameras. But I will try desconnecting them.

What catch my attention to this is that you say that if you hold your key next tho the steering column. That works for me 1 of 10 times. It is sooo difficult tho star the engine with or without the key in the steering wheel column. This makes me doubt about that the issue is my cameraa.

Spoolin335i · 05-28-2022, 04:15 AM

This happened to me as well! Battery was new in the key fob as well. I found out that the issue was the batter I bought from amazon. I bought the good Energizer brand from AutoZone and now no more issues. With the new amazon battery, I would many times be unable to unlock my doors or start the car. With the new Energizer brand batter, issue has been solved.

04-28-2022, 07:37 PM	#1
Krlos5411 Registered 1 Rep 2 Posts Drives: BMW X3 35i Join Date: Apr 2022 Location: LATAM iTrader: (0)	Occasionally key is not recognized to start the engine - BMW X3 2014 35i Hi guys, I'm new here. Just found the forum googling abou my issue. As the tittle said, my car somethimes gives me the issue that don't dettect my key. I need to push the start/stop engine button several times until the key is detected and the engine start. I just replace the battery of the fob key and the problem persist. I read in some other webs, that maybe the car battery could be low? The car hub should inform about that? The issue is also variable with the opening and closing of the doors, so I'm assuming that the key is the issue. I would like to check the fuses, but I couldn't find which one is the one the I need to check and if this can cause my problem. Anyone has this problem and solved it? Any idea or suggestion? This is my first BMW, so this issue is new to me. This is my car Thanks!!
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04-29-2022, 10:14 AM	#2
richardodn First Lieutenant 160 Rep 347 Posts Drives: '12 X3 35iX/'20 440ix cabrio Join Date: Dec 2018 Location: Denver, CO iTrader: (0)	I have the same issue. Fob battery and car battery are both fairly new. I can say that it happens less often than before those were changed. I'm of the opinion that it occasionally is just a little slow reading the key. When it happens to me, I just count to 5 before trying again. That usually gives the car long enough to read the key. __________________ 1986 Delphin 528e - Roof rack equipped lumber hauler. 2008 Platinum-Beige X3 3.0si - Current project 2012 Alpine White X3 xDrive35i - My new snowmobile. 2020 Estoril Blue 440i xDrive cabrio w/MPPSK - This car is a blast to drive.
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04-29-2022, 12:24 PM	#3
mike_MAN Private 21 Rep 89 Posts Drives: 2015 BMW X3 Join Date: Sep 2018 Location: MA iTrader: (0)	I had this issue and found out it was because of the rear dash cam I installed. After I install a front and rear dash cam system, the keyless entry was working intermittently and I had to put the key up to the steering column almost all the time. The key remote only worked about 1 foot away from the car also. I brought it to the dealership and they actually replace the CAS module but it was still finicky. I unplugged the read dash cam and voila, everything works fine as it should. Don't think the CAS module had to be replaced. I don't know if the wire I ran along the top side of the pillars were interfering with signals and sensor of if the unit itself was interfering with the sensor located at the top of the boot. For me, I was able to isolate the problem and found the error. Could be some inference issues.
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05-28-2022, 04:15 AM	#5
Spoolin335i Private 6 Rep 65 Posts Drives: E92 N55 335i Join Date: Nov 2015 Location: California iTrader: (0)	This happened to me as well! Battery was new in the key fob as well. I found out that the issue was the batter I bought from amazon. I bought the good Energizer brand from AutoZone and now no more issues. With the new amazon battery, I would many times be unable to unlock my doors or start the car. With the new Energizer brand batter, issue has been solved.
	Appreciate 0 Quote