Keyless Go question
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Joined: Jan 2021
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2013 C63 (W204)
Keyless Go question
backstory: I park my cars in a secure garage that only I can access and for convenience I leave the keys in the car.
with my other cars (Lexus and bmw with their equivalent of keyless go), it doesn’t matter how long it’s been since I’ve driven the car last - I can just hop in, hit the start button, and go.
the c63 seems to behave differently. If I haven’t driven for a few days, when I hop in to start the car (keys in the cup holder), it won’t start with the button and I have to remove the button and use the key to turn the ignition. Is this normal? Does the car somehow deactivate the button if it senses the key left in the car too long and then require use of the key?
with my other cars (Lexus and bmw with their equivalent of keyless go), it doesn’t matter how long it’s been since I’ve driven the car last - I can just hop in, hit the start button, and go.
the c63 seems to behave differently. If I haven’t driven for a few days, when I hop in to start the car (keys in the cup holder), it won’t start with the button and I have to remove the button and use the key to turn the ignition. Is this normal? Does the car somehow deactivate the button if it senses the key left in the car too long and then require use of the key?
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Joined: Mar 2006
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From: San Jose area
'19 E63S sedan
backstory: I park my cars in a secure garage that only I can access and for convenience I leave the keys in the car.
with my other cars (Lexus and bmw with their equivalent of keyless go), it doesn’t matter how long it’s been since I’ve driven the car last - I can just hop in, hit the start button, and go.
the c63 seems to behave differently. If I haven’t driven for a few days, when I hop in to start the car (keys in the cup holder), it won’t start with the button and I have to remove the button and use the key to turn the ignition. Is this normal? Does the car somehow deactivate the button if it senses the key left in the car too long and then require use of the key?
with my other cars (Lexus and bmw with their equivalent of keyless go), it doesn’t matter how long it’s been since I’ve driven the car last - I can just hop in, hit the start button, and go.
the c63 seems to behave differently. If I haven’t driven for a few days, when I hop in to start the car (keys in the cup holder), it won’t start with the button and I have to remove the button and use the key to turn the ignition. Is this normal? Does the car somehow deactivate the button if it senses the key left in the car too long and then require use of the key?
Thread Starter
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Joined: Jan 2021
Posts: 192
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2013 C63 (W204)
Later models have fobs that timeout for security (to prevent cloning) and need to be touched to waken if they sit in the cup holder, but the W204 doesn't have that technology. Have you tried changing the fob battery? Because they don't time out, the batteries don't last that long in those cars and weird stuff happens.
Now that you mention it, I do think I saw some sort of message in the instrument cluster that said ‘touch key to start button’ or something along those lines. I tried that but it didn’t seem to do anything
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2000 Acura NSX, 2012 C63 P31 (gone and not forgotten), 2015 C63 507
Maybe the next time this happens and it doesn't start, rather than take out the push start and put the key in....
Instead, press lock then unlock on the FOB to test and see what happens. That should activate the FOB or wake it up
Instead, press lock then unlock on the FOB to test and see what happens. That should activate the FOB or wake it up
MBWorld Fanatic!
Joined: Jun 2007
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From: Westmont, IL
2014 C63 Sedan
I see this happen with a lot of the cars in my inventory if they have not been driven in a while. Usually pressing the lock-unlock buttons on the fob from inside the cabin wakens it and the push start works.
Thread Starter
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Joined: Jan 2021
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2013 C63 (W204)
thank you both for this suggestion. I havent driven the car in a few days so I will try the lock/unlock this evening.
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2013 C63 (W204)
update - it seems that leaving the key in the vehicle is causing the fob battery to drain over the course of a few days. when I was in for the post-purchase inspection last Thursday, I watched them change the fob battery so I know it was new as of last week. Today when I got in to run an errand, I got a message on the instrument cluster that the fob battery was low. It appears as if leaving the key in the car causes the battery to drain very rapidly. Anyone else experienced this and/or have some technical information on how the keyless go system works?
This hasn't been an issue in my other cars, so there is something unique about the MB system.
This hasn't been an issue in my other cars, so there is something unique about the MB system.
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Joined: Mar 2019
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From: Bondi Beach , Australia
2013 W204 C63 AMG P31 Estate wagon
There have been a few threads dealing with different makes of fob batteries not working as good as others.
I had used Panasonic, Durracell, Maxcell and Eveready and they all seemed to only have short life and the change battery message on dash.
When I had my airbag recall done at the dealer in late 2019 they put Varta batteries in both fobs and so far they are both still working fine.
I had used Panasonic, Durracell, Maxcell and Eveready and they all seemed to only have short life and the change battery message on dash.
When I had my airbag recall done at the dealer in late 2019 they put Varta batteries in both fobs and so far they are both still working fine.
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Thread Starter
Member
Joined: Jan 2021
Posts: 192
Likes: 38
2013 C63 (W204)
There have been a few threads dealing with different makes of fob batteries not working as good as others.
I had used Panasonic, Durracell, Maxcell and Eveready and they all seemed to only have short life and the change battery message on dash.
When I had my airbag recall done at the dealer in late 2019 they put Varta batteries in both fobs and so far they are both still working fine.
I had used Panasonic, Durracell, Maxcell and Eveready and they all seemed to only have short life and the change battery message on dash.
When I had my airbag recall done at the dealer in late 2019 they put Varta batteries in both fobs and so far they are both still working fine.
Senior Member
Joined: Jan 2018
Posts: 415
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From: Whitehouse Station, NJ
2012 C63 P31 Sedan
I've heard that this is a potential issue with proximity keys. On some cars, supposedly this will happen even if the keys are outside of the car but somewhat close by.
I've seen people recommend keeping them in a different room in your house (assuming you have a garage) so they are far enough away to prevent communication between the car and the key. Another thing to try is seeing if you can fit in a thicker battery. I think the standard battery is the CR2025, but I know some were able to get a CR2032 in there. It is the same voltage and diameter, but with more capacity. I think the "25" and "32" at the end represents the battery thickness (2.5mm vs. 3.2mm)
I've seen people recommend keeping them in a different room in your house (assuming you have a garage) so they are far enough away to prevent communication between the car and the key. Another thing to try is seeing if you can fit in a thicker battery. I think the standard battery is the CR2025, but I know some were able to get a CR2032 in there. It is the same voltage and diameter, but with more capacity. I think the "25" and "32" at the end represents the battery thickness (2.5mm vs. 3.2mm)
Senior Member
Joined: Jan 2018
Posts: 415
Likes: 109
From: Whitehouse Station, NJ
2012 C63 P31 Sedan
Ok, so just after typing the above post, I remembered that I got the battery low message on my cluster the other day. I happened to have stockpiled CR2025 and CR2032 batteries for my other vehicles, so I figured I'd give the CR2032 a try, and it fit fine. It was just a bit tighter closing the key cover, but it went on with no issues, and the remote works perfect.
I'd suggest switching to the CR2032 to get more life out of the key fob. Both batteries are the exact same price online, so you'll be getting more capacity for your money.
I'd suggest switching to the CR2032 to get more life out of the key fob. Both batteries are the exact same price online, so you'll be getting more capacity for your money.
MBWorld Fanatic!
Joined: Mar 2006
Posts: 4,278
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From: San Jose area
'19 E63S sedan
update - it seems that leaving the key in the vehicle is causing the fob battery to drain over the course of a few days. when I was in for the post-purchase inspection last Thursday, I watched them change the fob battery so I know it was new as of last week. Today when I got in to run an errand, I got a message on the instrument cluster that the fob battery was low. It appears as if leaving the key in the car causes the battery to drain very rapidly. Anyone else experienced this and/or have some technical information on how the keyless go system works?
This hasn't been an issue in my other cars, so there is something unique about the MB system.
This hasn't been an issue in my other cars, so there is something unique about the MB system.
Thread Starter
Member
Joined: Jan 2021
Posts: 192
Likes: 38
2013 C63 (W204)
Ok, so just after typing the above post, I remembered that I got the battery low message on my cluster the other day. I happened to have stockpiled CR2025 and CR2032 batteries for my other vehicles, so I figured I'd give the CR2032 a try, and it fit fine. It was just a bit tighter closing the key cover, but it went on with no issues, and the remote works perfect.
I'd suggest switching to the CR2032 to get more life out of the key fob. Both batteries are the exact same price online, so you'll be getting more capacity for your money.
I'd suggest switching to the CR2032 to get more life out of the key fob. Both batteries are the exact same price online, so you'll be getting more capacity for your money.
Thread Starter
Member
Joined: Jan 2021
Posts: 192
Likes: 38
2013 C63 (W204)
People have also suggested leaving the key in a closed metal box so that it won't be able to communicate with the car. Of course you have to pop it out in the morning, so it's a bit of a pain. The battery brand does seem to matter; there have been multiple threads about that. Sadly, it took a new key fob design to truly fix. The late-model keys time out in a couple of minutes. I leave mine in the car. The other key is in a drawer and is never used. I recently measured the voltage of the batteries in both fobs and they were nearly identical. After two years.
MBWorld Fanatic!
Joined: Mar 2006
Posts: 4,278
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From: San Jose area
'19 E63S sedan
Also, since the key is sleeping in the morning if it's in the car, you can either touch it to wake it up or the car will wake it via a special wireless protocol. So you can see that there's no possibility of downward compatibility.
Last edited by whoover; Feb 13, 2021 at 12:40 AM.
Member
Joined: Jan 2020
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E63
One thing to watch out for, I've locked my fob in the car before. It was in the drink holder while I was giving it a rub down after a wash. My hand hit the handle and it locked, but oddly enough, it would not unlock from the handle. I had to go get the other fob to unlock the car, manually with the physical key. When I did, the alarm went off. I turned the alarm off the the fob that was in my hand; that I had just used the manual key from to turn the alarm off. I assumed this was all part of a failsafe in case keys were accidentally left in the car? Maybe one of my fobs was sleeping?
