Does anyone have a clue what the problem is, MB can't find the issues and it's leaving me stranded.
When turning the ignition key there is either a several second wait, or will have to retry.
Car has left me stranded, where key is in the on position but nothing registers and only auxiliary electrical works (stuff that works when no key in ignition.)
This problem started occurring after a service interval where half a dozen error messages required some steering parts to be replaced.
Knauz Mercedes kept the car for a week and could find no fault.

 

While I never had the same technical problem, I did have the same frustrations getting MB to take responsibility for fixing problems under warranty. Especially when a problem is intermittent, it's frustrating that the burdon of proof lies with the owner.

I found no easy answer. The bext I could do was to keep returning, escalating the problem. I got as far as threatening to park my car full of lemons outside the dealership in a no standing zone in peak hour traffic before one particular fault got fixed.

I hate being a pest, but there seemed like no option.

 

Intermittents in any type of equipment are the toughest ones to resolve for anyone. If they cannot duplicate and see the problem its unlikely they can fix it. It is without a doubt frustrating for the owner and the tech.
My solution when I do have an issue like this is to request that the tech and/or the shop forman take the car home with them over a weekend or just an evening or so to give it the greatest opportunity for the fault to show up. I have been fortunate as I have had maybe only one or two of these issues over the past 15 years of MB ownership. Those guys who complain about dealer people driving their cars are actually hurting themselves.

 

Thanks for the responses.
I posted b/c I've read no similar complaints for this car.
Twice today I had to wait 10 minutes for the car to register either of my keys and start. The dealership had the car for a full week and found no issue. I'm taking the car to the dealership where I've purchased 3 prior cars. Hopefully the salesman will take car of me.
The problem is the car has no error codes so the service guys have to know MB cars well enough fix the issue-and the 2010's electrical system is pretty complex.

 

Why don't you replace the batteries of one of the keys and see what happens? I say this because it is quite cold in the Northeast US (sorry, I don't know where you are) and if the batteries are weak, they would die faster in cold weather.

UPDATE:
I just checked and Knauz Mercedes is in Illinois so I would definitely replace my batteries (they are sold even at your local grocery store for a few bucks). If that is what the problem is, make it a point to call your dealer and yell for letting you troubleshoot it by yourself...

 

Sosh. agreed. Several times my car was with the dealer for up to a week for a mechanic to take home, or the service foreman to take home etc. I had no problem with this, I just wanted the faults fixed. My memory isn't 100% but I don't recall a single occasion when this lead to the problem being rectified.

On one notable occasion I had to escalate the problem to the point where they referred it to a non Mercedes owned facility. They managed to identify and solve it within a few days (the problem had been persistent for about 2 years).

I suggest if a problem doesn't get rectified don't be shy of escalating quickly (beyond the dealer if necessary) to alleviate frustration of all parties.

Noen of this helps fix your remote key problems though. Good luck!

 

It's not the battery in the keys, the dealer checked them both today. The dealership will probably keep the car all week again. The dealership is saying there is no issue. For me, the problem seems to occur most after the car is driven for 30 minutes or more and then restarted. This car had left me stranded 3 times in the past week.
The loaner c class car so tiny, cannot wait for the lease to end.
So ridiculous.
Sydunipete, what was your car's issue?

 

Don't ask. My problems were many and varied. I had a 2006 ML500, but I believe the subsequent models are much better. Mine was certainly a "Friday car" and reflects poorly upon both the mechanical quality control in Alabama, but more importantly the approach to quality and improvement through the Australian dealer network. It was also a learning for me on the practical uselessness of the Australian consumer protection laws. (We have no lemon law for example.)

I've tried to obliterate the Mercedes experience from my mind. I replaced the ML with a Subaru Liberty GT (in the US you call it a Legacy). It's every bit as fast, it's far more economical, it hasn't broken down once and I'm much happier. Sure it's not a merc. People don't look at the car as much. It's a bit rough around the edges. But then again I don't know every service rep at my dealer by name.

With the ML:

I had lots of problems with the transmission. Software upgrades made it better, but still not acceptable. There are plenty of posts here about rough 2-1 changes. I got stranded once when it went into neutral when accelerating.

Parking sensors repeatedly false alarmed. (Took 3 attempts to fix despite being very obvious and easy to repeat.)

There was a noise in the sub frame. Took escalation to a mercedes recommended chassis specialist to fix. From memory about 2 1/2 years of fobbing me off to finally get the problem fixed.

Failed cam shaft sensor.

Weird COMAND sound system problem that could never be rectified.

Steering components were replaced several times.

That's just from (bitter) memory. Apart from the nuisance factor and giving me something to talk about at dinner parties, the practical implications cost me significant dollars. I run my own business, so 52 days in 3 years (from memory) with the car at the dealer cost me a lot of time and stress that I didn't need. I felt unable to sell my car privately in case the buyer was equally as unhappy as me and decided to direct their anger at me, so I had to trade the car taking a much lower exit price than I would have got from a sale.

And you got a C class. I got an A or B class, and on one occasion they stuffed up the loaner booking and I got a 10 year old Toyota Camry!

Don't flame me if you are happy with your MB experience. I acknowledge that this vehicle was a lemon and not indicative of the brand as a whole. But I take two conclusions from this:

1. I feel MB Australia's approach to quality and improvement is non existent. (When I owned a Toyota I was surveyed in-depth everytime I even thought about touching the organisation, at Mercedes in all my problems I only ever received one survey "please tell us about your experience". If you don't measure something you can't fix it.)

2. My view is that Australian consumer protection in regard to motor vehicles is a farce.

archtype25 - are you sorry you asked?

 

Update... MB kept the car for another 2 weeks and the issue turned out to be a bad ignition module.
I got the car back and it's starts phenomenal and looks great.
But this morning...a warning light comes on the dash and the navigation/stereo won't work and dash says to reset the system. I'm taking it in tomorrow.
This car is a lemon and an accident waiting to happen.

 

Try another dealer. I use to have mine serviced at Knauz, but after a few bad results, I switched to Motor Werks Barrington., and have been much happier there.
I had similar issues at Knauz as you, I would take it in for one item, and 2 other thing are damaged. At Barrington, the customer waiting room overlooks the repair shop, so you can "keep an eye" on your ride being repaired.
PM me if you need the name of the service writer and tech I use. Hope it works out.