The problem: Key is not recognized by the car, however, the fob locks and unlocks the doors, raises and lowers windows and top.
But I must remove the start button and insert my key fob to start the car.. Sometimes, after starting the car with the key, I can replace the button
and it will start the next few times.

Any ideas on how I can correct this? Is there a secret way you have to hold your mouth while cranking? Maybe close one eye?

Thanks for the help.
Frank

Do you have a 2nd key? Does touching door handles still unlock?

No second fob and no, the doors do not unlock with touch. What's my next step?
thanks for your help.
Frank

How fresh are fob batteries?

You definitely want a second fob, but be prepared to take a second mortgage or home equity loan.

The dealer can order an "emergency key" (the metal cut key) based on your VIN with proof of ownership. However, the fob part requires programming with the car present. Should you lose your current key, things get more complicated. You will at least need to have your car towed to a Mercedes dealership. Older cars (2014 and earlier) could have new fobs programmed by a licensed locksmith, but not newer ones.

If you are having to insert and turn the key to start the car, then it could be the battery.

While this kind of sounds like an EIS issue.
Your car is way too new for this. And R231s don’t appear too susceptible to this issue, It would be out of the norm, not impossible but out of the norm…

What’s your Mileage? Main battery checked or replaced? Ever had your Aux battery replaced/checked. Not just voltage, but either load tested or resistance tested.
Though your car may start, it still may be out of specification.
Can lead to issues you’re experiencing.

I would definitely get another key. You should have two (at least)
Good Luck

Thanks CR,
Surprising event today.... Had the fob in my pocket and I touched the driver's door handle and the locks popped. Put the fob into the key hole and started the car.
Mirrors unfolded and dash lit up. I let the car run for a couple of minutes and shut it off. Inserted the Start/Stop button and pushed it in. Car started right up.

Go Figure.!!!!

I have thought about getting a second key.... but with my " Face Lift" 2017, I can get a new one only through the dealership for $700.00 . I don't understand it,
I am considering getting the entire ignition key set up. I see I can get them on Ebay for what seems a fair price.

What are your thoughts on that.

Frank

Make sure you use QUALITY FOB batteries. I thought I read somewhere that people were having issues with certain brands of batteries. Maybe they we’re just old.
Other problem with second hand FOBS is history. Maybe it’s been washed a few times in the laundry. You’d be surprised how often that happens!

Thats also why I suggested having your main battery (and aux battery) checked, via load test or resistance test.
Have they ever been replaced or are they original?
You probably don’t have XENTRY (factory diagnostic software) but it can also be checked in the charge balance section.

Start with the basics first. In any troubleshooting these cars, first thing the WIS (factory repair manual) always starts with is: check condition of batteries.

All the R231’s (and modern MB’s) have to get the keys from Germany. They are programmed specifically for your car. One of the reasons (amongst others) MB’s are tough to steal is because of this tight control. I know some brands you can actually “generate” keys in the field. It’s how thieves steal some brands of cars very easily.

I would also get a quote from several dealers if you have that option. The price can vary a few hundred dollars It’s why it’s important to get BOTH keys when you buy these cars second hand.

That will be a slippery slope. It would cost MUCH more in labor than buying the key, as you have to program/mate everything to your car. It’s not like the old days where you could just swap out a lock. If you ever lose the key, the car will be immobile until they can get a key from Germany. I don’t know about you, but when things like this happen to me, they tend to happen at the worst possible moment.

When you get the new key programmed, they can also code out any old keys that are “floating around” out there.



Good Luck

If I remember correctly, any car with the fbs4 security system has to have keys from Germany. Fbs3 was on the 231 up to 2013 I believe. With fbs3 you can get a locksmith to duplicate a key.

If we look at PN’s for our cars,
EIS on US R231 2013’s is PN a2319055000 which is FBS4.
(Same part all the way up to 2020)
https://www.mbpartscenter.com/oem-pa...IFJlc3VsdHM%3D

That’s the only PN available for our cars. You can see vehicles compatible with that part number in the link above.
Not sure if the early Euro cars are different. (I don’t believe so)

But unfortunately, there’s no reliable source of keys for us in the US other than dealer


Good Luck

Interesting that that part number goes back to the R230, but only for the AMG SL65.

I will replace the FOB battery even though I replaced 3 or 4 months ago. Sometimes those batteries sit on the
shelves for quite some time.

Last month the " Accessory " battery was replaced. I am planning on checking the "Starter" battery and if it's even close to
being bad, I'll will replace it.

Then I'm going to bite the bullet and make a visit to the dealer and get an additional FOB.

Get a Panasonic battery from a known reputable seller, lots of counterfeits especially on Amazon and Ebay

I bought additional key fob from Smith Motor Sales of Haverhill (I didn't think Mercedes even allowed a dealership to name itself like that) for less than HALF what was quoted at Mercedes of Boston. Provided proof of ownership via email. A second key is nice to have, even if it's just to have a shop leave my car locked outside for me to pick up after hours, then come back another time for my other key.

Sorry, this is off-topic but can you share how to get to the charge balance section? I just got the XENTRY setup and just learning how to use it!

Here you go. (May be in a different area depending on which car you’re scanning and which version of XENTRY you’re using.)

https://mbworld.org/forums/sl-class-...ml#post9091277