2009 E350 RWD sedan
Auto, 135k miles

Quick question - how long should a brand new, from the dealership key fob take to initialize once inserted into the ignition?
I have a unique situation, I had my EIS and ESL replaced AND a brand new ignition key was purchased as well (all parts ordered from and picked up by me at the Merc dealership).
After the shop key was used to program the ignition switch my mechanic inserted the new key and got the expected message of key initializing.
I'm seeing this NORMALLY this would only take a few minutes, maybe a few hours at the most.
WE HAVE HAD THIS KEY INITIALIZING MESSAGE FOR 26 HOURS NOW (battery charger connected to the car overnight while key was inserted).

Mechanic said he talked to Merc tech and a third party programmer and they said it COULD possible take up to 90 hours.
That sounds CRAZY to me. No matter how many old codes had to be dumped and new ones rewritten that seems like an excessive amount of time.

Have to mention that the ignition key from the dealership was originally ordered to work with my original EIS before that was replaced (parts guy at Merc somehow ordered it without updating the info for the replacement switch, didnt think that would matter as much).

Could it be an issue with the new key?
I have two old keys but one stopped working a year or so ago and the other stopped working a few weeks ago causing me to have the car towed to my mechanic.
Both of those keys lock and unlocks doors and pops trunks but would not turn in the ignition, at all.
Should my mechanic look to remove the key and try reinserting it and maybe starting the process over?
Could the initialization have frozen at some point?
Anyone seen this process take over a few hours tops?
Any info would be greatly appreciated.

 

Thanks for the reply.
Question - if the key will never work why didnt the dealership order a new ignition key to go along with the new EIS when it was purchased a few weeks ago?
Also, I assumed at least one of my old keys would have worked if this repair went as originally planned.
Are you saying each time a EIS is replaced on a W211 a new key is needed and the old keys will never work again on the car?

 

Both times I ordered new "extra" key fobs for my W211, I just inserted the key, started the car, and drove it while the key was initializing. It picks up the process where the process was left off when the car is powered down and then restarted. I remember the second time I had the message for two days of commuting to and from work.
-Key fobs are assigned to one of eight key tracks and one of three key segments (think rows and columns).
-Factory key fobs delivered with the car are assigned to Track 1, Segment 1, and Track 2, Segment 2.
-There is a difference between an "extra" key and a "spare" key.
-if you purchase an extra key, it will be assigned to the next track's segment one, e.g. Track 3, Segment 1.
-if a key is lost or defective and you purchase a "spare" key it will be assigned to to the defective key's track but next segment, e.g. Track 1, Segment 2. If the original key is lost, Mercedes techs can disable the track/segment position assigned to the lost key fob so the finder cannot us it to steal your car.
-if you manage to lose the original key plus its two replacements in Track 1, Track 1 and all three segments are disabled. (I don't know why but I conjecture it has to do with memory tables in the firmware.)

Key point one: a spare key replaces a lost or defective key created previously. It will not be operational until it is "taught in" to the car's authorization system (see info below). It is assigned into segment 2 or 3 of a key track and the previous segment's assigned key will no longer work.
Key point two (catch the pun?): an extra key is assigned into the next key track's segment 1. You can have as many as eight keys that function in your vehicle with each key assigned to Tracks 1-8, Segment 1. If you lose the key in Track 5, Segment 1, and purchase a replacement for it, the new key will be programmed into Track 5, Segment 2.

Key tracks can be disabled or enabled using STAR diagnostic system and the workshop key.

The above implies you use someone who is familiar with and trained on the DAS authorization system. This may be the time for you to punt the problem and pay the dealer.
Good luck to you.

 

Did you get this issue resolved? I have same exact problem.