goherdibg

4 times (that I can specifically remember) over the past week I have been unable to unlock my car by simply pulling on the door handle. It's as if the car does not recognize the key being close to it. The first 3 times I took the key out of my pocket and pressed the unlock button and was able to open the door. I put the key back in my pocket and was able to start the car.

The last time it happened I walked away from the car and back into range and was still not able to unlock the car. Again, I pressed the unlock button and was able to start the car.

It's a little embarrassing when going to lunch with a group of people from work, walking up to a new (2.5 months) car and pulling on the door handle multiple times and nothing happens. When the guy with the new Camry jokes "hmmmm....my car opens every time" it does sting a little

So far I have been able to unlock the car every time by pressing the button. I am a little concerned this problem could evolve into something more - especially when my wife is driving it.

Anyone else experience this?

2015MBC4MATIC

I had this and someone on this forum advised me to keep the cell phone away from the key. No problems since then.

abstractls

Yup key your keys and phone in different pockets. Any chance you have n iphone?

2015MBC4MATIC

Yes, I have an iphone 5s.

goherdibg

Yes, but I always keep my keys and phone in a different pocket. Learned that lesson the hard way on an older iPhone (scratched screen). If it happens again, I will try and make a mental note of things in my pockets and inside the car.

I know on one occasion, my phone was inside the car when it did not unlock. I ran inside a convenience store to buy something and left the phone in the ashtray/cupholder space with the lid closed.

coladin

I've had 4 Benzes with Keyless Go and this is not a C400 issue rather a MB issue that happens sporadically, as annoying as it sometimes is. I have sworn at my door handle in previous benzes as curious onlookers looked at me as I yelled " Open the effing door!", must have looked crazy

mihaelb

Nah...I'm sure they thought you have voice-activated Keyless Go

jcmarx

Yes I have the same issue. So far it has happened twice on my C400, about 1 month old.

Selling me a vehicle that locks me out seems a little fraudulent in a way. I plan on talking to my lawyer about this to see if I can get my money back.

seanvree

Yep, I have also had the same issue. Really weird. Totally intermittent.

djdj

Three thoughts.

One, the only time I had an issue unlocking the door by just pulling the handle was after I had locked the car with the remote -- I don't know if that is related or not. It unlocked fine with the remote.

Two, you may have a low battery; I had one in one of my remotes. The dash told me it was low, but the manual shows an easy way to test the battery strength.

Three, it may be operator error. Look at other threads here where people have not been able to unlock because they are touching the lock sensor while trying to open the door.

Oh, and there is a workaround if keyless go is not working at all. See the manual.

jcmarx

I love your logical approach. #1 is definitely not it. #2, battery, I would hope the car would tell me when the battery is low. But I will take your advice and see how to test it.

Three may be the one. Being new to the car, I suppose it is possible that my thumb may have been touching the outer sensor. I will be more alert to that now. In fact, the second time it happened, I was with someone and they beat me to their door. They may have been pressing on the lock part of the handle while I was trying to open.

Never let it be said that I am not open minded. I will try these things. Thank you for your post.

goherdibg

I will definitely have to pay attention to see if someone else possibly has their hand on one of the other handles and is touching the lock indent.

That could explain it as it has happened when other people are with me as far as I can recall.

jolt8631

If the C is anything like the wife's Audi, it doesn't make any difference if someone else is touching the lock section - UNLESS they have a key to the car with them (ie your partner, perhaps). The logic has to recognise the security code.

The same is not true, however, if you (the person with the key) inadvertently rest the back of your thumb onto the outside of the handle, as you grab the back of the door handle to unlock. I know, in our first few weeks of ownership, we had to "think" about it, just a little, to train our movements - seems really dumb to say, but it was definitely catching us out to start off.

Since then, not an issue - apart from one occasion when my missus had her key buried in the bottom of her bag - under her iPhone - got in and the car wouldn't start (bringing up a "no key detected" message) and then promptly re-locked the doors with her inside - PANIC! The internal door release wouldn't open it, nor the central locking release button.

After that, I had to show her where the Emergency Tailgate release was, before she would get back in!

Anyway, that was Audi. Since making sure the key fob is always separated from her iPhone, it has been flawless.

jcmarx

If the FOB is close enough to the car (which in my case it was), the car doesn't care who opens it or from which door.

Your story about wife being locked in the car, ouch! I would never be able to get mine in it ever again! Hopefully I read that right and it was an Audi!

jolt8631

Of course, I was forgetting the MB system is quoted as a proxity system, as opposed to the Audi which works by contact only.

And yes - it was the Audi.

goherdibg

It happened again last night after work. I was alone so no one else was touching any other handles. My phone was in my jacket pocket and my key in my pants pocket. I walked around the car and tried every door handle. I walked away and came back and nothing.

This time I pressed the lock button on the remote instead of unlock. The car locked and the lights lit as they normally would when locking the car. When the lights went out I grabbed the driver side door handle and it unlocked.

My mother-in-law had a similar issue with her RX300 and because it too was intermittent she ended up going back and forth to the dealer 5 times. I honestly don't even know if the problem is fixed but she does not talk about it any more.

I don't want to end up taking this car in multiple times and each time have the tech say "worked for me". I know it is intermittent which is going to make this problem hard to solve. Maybe I should take a video the next time it happens?

jcmarx

Same thing here - happened this morning. I took my iPhone and security badge off and placed them on a workbench about ten feet away - still no response from the handles. I was very careful to only touch the inside sensors. I tried all four handles, no luck. Used unlock button on the FOB and it opened, then performed as normal.

So that completely kills the myth of the iPhone or any other magnetic interence. Next test for me is to replace the batteries in the FOB.

A note to anyone who may be with MB or know someone there: this is a highly embarrasing bug when encountered in the presence of others which causes extreme brand questioning from those that see it. I really don't understand how you are not all over this (maybe you are and we just don't know). Furthermore, if a person were a doctor or someone taking a person to the hospital for some reason, this problem could present very costly liable damages and instigate class action lawsuits (a nightmare for brand image). I'd be all over it if I were you. And if you are, how about some communication to your customers?

goherdibg

This just happened again today when going to lunch. About 20 times in total over the past month or so.

I will address this with the dealer when I go for my first scheduled maintenance but was wondering if anyone else has talked to their dealer about it?

Jinzen

I gently touch the handles and the car always unlocks. 100% success rate so far within about 4 months of ownership.

CO2010

Same here. No issues at all

BlackjackM

It almost seems like the car is not "awake" and looking for the key at times, and when the lock or unlock button is pressed it then senses it. Strange.

BenzC400

Keyless Go has worked flawlessly for me.

jbbeauso

Same problem. Happens maybe once a month. When it happens the remote unlock or any other button on the key fob also don't work. It's extremely ebarsaing! Makes you look like you are trying to break into your own car! If you walk away for 5 minutes and return it works all of a sudden.

mplex

Could the problem be the feature on the key to put it to sleep? If you press the lock button twice, the key flashes a long red flash and the key is in sleep mode, disabling the keyless go. As soon as you press a button again, the key wakes up and works normally. Depending on how the key is stored in your pocket or where ever, if the button gets pressed twice, you would have the problem.

StanNH

No, because everyone who has had this problem has hit the unlock button several times. Same for the ignition problem ... you can hit those buttons all you want, but it won't do anything. (A couple of posters said they did have success after hitting the unlock button, but I could not replicate that when I tried.)