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yes, it is connected and reminds me. Which is great at the mall and work. I'm now immune to the notice when I get home.
I guess don't make it a habit though, don't want to forget to lock the car after arriving to your destination when the car is not home, like in a mall parking lot.
Yes, the boundaries are not exact. If the key is close enough it will start. For example if I place mine on the pano roof then the engine starts, but if I place it on the metal roof then it doesn't. So yes if OP hangs their keys very close to the car, it might start in the garage, but as soon as they pull out the "key not detected" warning will light up in the instrument cluster. One has to blatantly ignore the warning to find themselves at their destination w/o the key. Now this is assuming there's no malfunction. If OP can start the car w/o a key anywhere nearby, then there's a serious issue.
I should also add, that the key fobs have motion sensors and go to sleep after two minutes if there is no motion. So if the key fobs are just hanging on the wall, they go to sleep and no longer send out a signal until they are woken up by motion. So it's even less likely that the car would start if the keys are hanging on the wall somewhere unless there happens to be an earthquake at the same time.
I wonder in that case, is it because the motion sensor might be broken and it is keeping the key awake at all times?
I think we can all agree that something very strange is going on here. Things don't really add up as portrait. As for keeping the car unlocked in the garage and draining the battery, that's a myth. Combined with the key fobs going to sleep there's really no negative impact. I've kept my cars unlocked in my garage for over a decade. What mostly drains the battery on these modern cars is the telematics combined with the always on cellular connection that stands by to receive remote commands from the phone app. You could actually argue that a locked car drains the battery even more, because the alarm system is active while the car is locked. For long term parking there's the standby mode that can be activated which turns off the online services as well as the alarm and any other consumers that normally stay powered. Even the door modules shut down after a while to preserve the battery and have to be woken up by pulling on the handle.
None of this really changes what's at odds here with this story. The fact that OP seems to be able to start the engine w/o a key fob nearby and seems to completely ignore the warning in the instrument cluster that the key can no longer be detected while driving away from the house. With a properly functioning vehicle, this doesn't add up.
Got me curious, as not sure if it is just me but the "key not detected" doesn't seem to happen unless the key is gone and that a door is opened at least once when engine is running, this behaviour might had been changed on newer MBs though and that the audible prompt and message on the dash appears as soon as key is not detected? I guess the easiest way to tell this is start the car, disable the key (like double tap lock button or remove battery) and see when and how long it takes to prompt about it. Might just be my vehicle that is not constantly searching for the key though until a door is opened.
As they say, correlation does not imply causation. Your original battery was likely defective. I also don't drive my car very much. It sat in my garage for several weeks during the pandemic for example and I mostly only drive on the weekend. The Mercedes me app most of the time says my battery is partially charged and it takes a few days of driving for several hours before it shows as fully charged. Battery never went flat. I'll also submit the following screenshot. The nice thing about the standby mode is that it says exactly how long the car can be left w/o needing to charge the battery. As you can see, it's 21 weeks for my car. Now that was with a full battery after having it on the trickle charger overnight. I was going away for a month, so decided to fully charge the battery before leaving. W/o hooking it up to the trickle charger beforehand, it usually says I have about 7 weeks. My car is 4.5 years old now with the original battery and never locked while parked in the garage.
One of the things that many don't realize is that the AGM batteries that are in today's cars charge much slower than the lead acid batteries of yesterday, but they deal much better with the power demands of today's electronics in cars. It's pretty much normal that the battery is rarely fully charged, partly because modern cars even w/o mild hybrid have a certain level of recuperation via the alternator when coasting and they later use that energy to power things like the electric power steering, oil pumps etc., and decouple the alternator from the engine to save fuel . Beyond AGM batteries, lithium batteries are even deliberately kept at partial charge because it extends their longevity. Most people who give battery advice still think in terms of lead acid batteries of the past and don't really understand AGM and lithium batteries.
If you are such an infrequent driver, then the standby mode is what you should be using instead of worrying about locking the car in your garage. Actually never mind. Just realized you have a W212. This is the W213 forum. We are talking about newer cars, although I reiterate that I left my cars unlocked in my garage since the early 2000s, albeit initially with remote unlock key fobs, and not keyless go type key fobs, but my current car and previous car had keyless go. The keyless go feature in the W212 is likely more power demanding than in newer cars.
I think we can all agree that something very strange is going on here. Things don't really add up as portrait. As for keeping the car unlocked in the garage and draining the battery, that's a myth. Combined with the key fobs going to sleep there's really no negative impact. I've kept my cars unlocked in my garage for over a decade. What mostly drains the battery on these modern cars is the telematics combined with the always on cellular connection that stands by to receive remote commands from the phone app. You could actually argue that a locked car drains the battery even more, because the alarm system is active while the car is locked. For long term parking there's the standby mode that can be activated which turns off the online services as well as the alarm and any other consumers that normally stay powered. Even the door modules shut down after a while to preserve the battery and have to be woken up by pulling on the handle.
None of this really changes what's at odds here with this story. The fact that OP seems to be able to start the engine w/o a key fob nearby and seems to completely ignore the warning in the instrument cluster that the key can no longer be detected while driving away from the house. With a properly functioning vehicle, this doesn't add up.
To clarify, when I do drive away, I do not get a warning that the key is not detected.
To all of the comments about the key hanging on the hook nearby, I REALLY do not think that is it. I've had several mercedes as well as other brands, no car has ever been close enough to the hook to notice the key and my Eclass is the car furthest from the hook. It's a good 30+feet. I know of at least one instance where when I got home both keys were on the kitchen counter, which is 70+ feet from garage. But even if so, it does not explain why when I was at Publix my car started back with no issue. (for which I was thankful from a convenience point!)
Obviously this is a problem that no one here as seen. I appreciate the feedback. I'll be going to dealer soon.
I must say, I have never experience this or heard of anyone that has, but to think this is normal or you were lucky is not a response most people would expect. Are you saying you can start the car without the fob, go to Target, and realized you did not bring the fob and was still able to start the car again?
Yes, that is exactly what happens sometimes. And, other times, with the key sitting in the key cubby in the car, it won't start until 3 or 4 attempts. Other times when I do forget my key, it properly tells me that the key cannot be detected. The issue, so far, cannot be duplicated with a set of circumstances. So far it appears random. But, I know few things with computers are random, so I am trying to keep track of all factors to try to find the common factors.
I'll say it again — by not getting this fixed, you're risking theft, and your insurance company would be very interested in this thread. There's NO way that your car should start without the electronic key fob being present. If YOU can start it, than so can anyone.
Here's what you should see when you try to start the car without the fob being in the car or otherwise within range (two screens):
I'll say it again — by not getting this fixed, you're risking theft, and your insurance company would be very interested in this thread. There's NO way that your car should start without the electronic key fob being present. If YOU can start it, than so can anyone.
Here's what you should see when you try to start the car without the fob being in the car or otherwise within range (two screens):
Thank again. As stated, I am going to the dealership after seeing this is a very unique, heretofore unseen, issue.
As for the insurance aspect, I appreciate your concern. Many people would share you seemingly valid assumptions, but, as a lawyer, I am well versed in contract and insurance law. This would not negate any claim of theft. Theft is the least of my concerns since it is never left unlocked except in my garage, and if some thief is going to get by my security system(s) to get into the garage to get the car, I assure, they are sophisticated/brazen enough to get the car without the key in any circumstance!
'You're probably right, but insurance companies aren't your friend, and their lawyers can be pretty aggressive in their attempts to keep their employers from having to pay claims. To me, if you were to leave the car unlocked knowing that it can be started sans key, it might arguably constitute contributory negligence. Get it fixed.
To clarify, when I do drive away, I do not get a warning that the key is not detected.
To all of the comments about the key hanging on the hook nearby, I REALLY do not think that is it. I've had several mercedes as well as other brands, no car has ever been close enough to the hook to notice the key and my Eclass is the car furthest from the hook. It's a good 30+feet. I know of at least one instance where when I got home both keys were on the kitchen counter, which is 70+ feet from garage. But even if so, it does not explain why when I was at Publix my car started back with no issue. (for which I was thankful from a convenience point!)
Obviously this is a problem that no one here as seen. I appreciate the feedback. I'll be going to dealer soon.
I would had advised try storing the key upstairs or somewhere far far far away from the car and try starting it if it to test the hook theory (even if we were to agree with you, it is a fun experiment and rules it out).
Edit: Never mind, didn't notice you mentioned the car started in public with no issues.
Since you decided to take the car in, hopefully they figure it out for you. Will appreciate your update once they do figure it out, as it is a mystery for sure and you know... curiosity killed the cat.
Last edited by W205C43PFL; Jun 28, 2023 at 03:37 PM.
Reason: Never mind, didn't notice you mentioned the car started in public with no issues.
'You're probably right, but insurance companies aren't your friend, and their lawyers can be pretty aggressive in their attempts to keep their employers from having to pay claims. To me, if you were to leave the car unlocked knowing that it can be started sans key, it might arguably constitute contributory negligence. Get it fixed.
I guess they will need to prove that it is the owner's negligence leading to the car getting stolen. As well as proving that the owner is aware of this issue with the car that led to it getting stolen (other than documentation from the dealership when the vehicle gets taken in somewhere along the lines of: client stating key starts without key present) but OP seems to be taking the car in to get it addressed so all of this never will be a concern anymore.
There is a third key. Now I just need to find it. The third key explains everything. It explains why my car tells me the FOB battery is low despite me changing the battery in both of my FOBs TWICE, first time assuming I got a bad batch of batteries.
It explains why sometimes when I do forget my key the car won't start. (because the hidden third key has been still for X period of time therefore making it go to sleep mode)
It explains why when I do happen to drive somewhere and realize I don't have a key with me I can get back in my car and it always starts. (I always wondered how did it know I was not home and it allowed me to restart the car to go home and get a key)
Dealer confirmed a third key was made for the car without resetting frequency.
So, my belief now is previous owner lost a key. (it fell out of his/her pocket and is under a seat somewhere) and assumed it was gone forever, so they just bought a new one.
I've given it a pretty good college try looking under the seats for the key to no avail. But, it may be wedged in the jumble of wires and relays under the seat so I am going to research how to remove the seat(s) and look for it there. (I'm hoping for my purposes, I can just remove those four bolts) If it is not under the seats, I'll be back at square one. (well, square 3, I am 99% convinced the key is in the car, even if I cannot find it)
In hindsight, I do believe all of the times I have been able to start it "without" the key it was when I got home, ran inside, changed clothes or did some other remedial task and in a hurry went back to the car sans my keys.
It has been quite the mystery. I look forward to finding that missing key somewhere in the sled!!
I guess the third key might be useful to have once you found it, but in the meantime they should be able to deauthorize it. You don't really wanna park you car anywhere knowing there's a key inside that will let a thief get in and drive away.
They can't. When I lock my car with the FOB in my hand (or app), the FOB in the car cannot unlock it by proximity. I know that from trying with my others as I always lock my key in my car at the airport and ballgames and use my app to unlock. I do apprcieate your concern of theft, but that really is the least of my concerns. If someone wants to steal an E Class, they already have a plan in place!
I guess the third key might be useful to have once you found it, but in the meantime they should be able to deauthorize it. You don't really wanna park you car anywhere knowing there's a key inside that will let a thief get in and drive away.
They cannot deauthorize it without having it. The only way to do that is to change the frequency in my car, which would then require to reprogram the two keys I have. Not a chance I'm paying $2000+ for that!
They can't. When I lock my car with the FOB in my hand (or app), the FOB in the car cannot unlock it by proximity. I know that from trying with my others as I always lock my key in my car at the airport and ballgames and use my app to unlock. I do apprcieate your concern of theft, but that really is the least of my concerns. If someone wants to steal an E Class, they already have a plan in place!
But when the FOB is near my car, say in my pocket, I can open the car's locked door by simply touching the door handle (or lock the door the same way).
Is that the case when the FOB is locked inside the car? (No, I don't want to experiment! With my luck I'd never get back into the car without smashing the window with an ax!) )
Locate a Bluetooth device with an app such as WunderFind. WonderFind is installed on a smartphone. It will list all bluetooth devices that are detected along with a an estimated distance.
But when the FOB is near my car, say in my pocket, I can open the car's locked door by simply touching the door handle (or lock the door the same way).
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No. As I understand the reason, once the key does not move for X period of time, it is "dormant" and will not lock/unlock/start the car. If you take your fob and set it on the ground next to your car, it will likely start. Leave it there overnight and then start it, the car won't start until you move the FOB enough to detect motion.
Locate a Bluetooth device with an app such as WunderFind. WonderFind is installed on a smartphone. It will list all bluetooth devices that are detected along with a an estimated distance.
does your picture show your FOB? I downloaded the app and it is not showing the fob in my hand. Are they Bluetooth?
does your picture show your FOB? I downloaded the app and it is not showing the fob in my hand. Are they Bluetooth?
Key fobs don't use Bluetooth. I was gonna respond to the post above. Newer key fobs use UWB (Ultra-wideband). Older ones use lower frequency RF pulse signals. UWB is what allows digital keys with newer smartphones such as the iPhone 11 and newer. UWB is rapidly adopted for security reasons, because it allows for the use of time-of-flight calculations. The signal is timestamped, which allows the car to determine how far it travelled to determine if the fob is actually near the car or if the signal was relayed. BT has proximity capabilities as well, but it's not very secure. Only Tesla uses BT to unlock their cars.
Yes. I also checked the "spare tire" chamber and other known cubbies. Wherever it is, it is lodged in there good and hidden!
So couple more places
front sears between the cushion and back rest.where it leans. I have found quarters, keys and bills there.
The under the door cup holders might also be another squirrel spot.
It might have fallen off in the seat belt hole of the rear seat. You will have to pull up about 5 inches from the corners to remove the rear seats. Do it carefully if they are rear heated seats.The install takes adjusting the seat belt buckles but fairly easy.
It might have fallen off in the seat belt hole of the rear seat. You will have to pull up about 5 inches from the corners to remove the rear seats. Do it carefully if they are rear heated seats.The install takes adjusting the seat belt buckles but fairly easy.
This is my top suspected location. I've detailed my car twice in the past year and routinely keep it pretty clean. I removed both front seats last night after I found out it is just the four bolts if you are not removing them from the car completely. When I have more time (and it is not 103 in my garage!) I am going to remove the seatbelt covers to look in there. I took my FOB to see if it could fit in there. It is not easy, but if it fell there and then someone put pressure on it, it can go in there.
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Solution Found! - Probably
