I got this 2006 MB CLS500 a few months ago... with very low miles (25K) from a Mercedes Benz dealership in SE Florida.
I got it without warranty (not certified).

Anyways... the car is beautiful, tight, even still has some of that new smell... never smoked.
But one day, after I had been driving around and come back to the parking lot from the pharmacy, NO more starting.
It accepted the key, let it turn, the dashboard controls light up normally... EVERYTHING seemingly "normal" except NO starter kicking in.

Called Mercedes Benz Road Side Assistance... they show up only 10 minutes later, dispatched from a dealership 9 miles down the road... with battery tester, new batteries (ready to be sold)... but, the tech can't blame the battery. Brother in law pull in with the "other" key... SAME!

So AAA is called in to get it to the dealership down the road... it's late in the evening. But luckily NOT too late for the service rep to sit in the car an try to crank it with BOTH keys... car does not start.

A couple of days later, MB calls me, to inform me that they started to work on the car but couldn't get it to fail. In other words, it recuperated all by itself! Nice. They ask if they ought to keep it a couple of days to see if they can get it to fail... about two weeks later, YES, it did fail, but not long enough to allow the technician to find the culprit.
Weeks have gone by now... from the last phone call I got, I gather they would like to see that car OFF their lot. I told them "NO". They know it did fail, it HAS failed again, I am not going to take it on the road, just to go thru the AAA-routine again.

I don't know it one still hits the starter with a hammer anymore, like we used to in the old days, to see if the pin got stuck... I'd reckon that IF that's still something one does, they would have done it.
I am told that if the key receptacle was having issues, it would NOT recognize the key at all... NOT let it turn, NOT turn on the electrics, gauges etc. Still, even during starter failure EVERYTHING ELSE lights up normally.
I would suspect a relay... but who am I to share theories with a today's MB technician, even if I could fine tune register carburetors "by ear".

So, IS this an issue that is know, maybe even common?
How can I help the technicians at the dealership?

Thanks for hearing me out! I KNOW it's a loooong one.

... J-D.

 

I had a similar problem (different kind of car) and it was a dead spot in the starter. I think that is why we hit them with a hammer. In still another car the ignition switch went out and it was an intermitant problem , but when it didn't work, I got lights on the dash but it acted as if the battery was dead.

 

Yes, I remember those days! Back in Europe, we used to laugh about it, state that the "Bendix" got stuck and give it a nice beating, et volia!

Not on those cars anymore.
On other Forums where I also posted on this issue (which HAS been resolved, read further), several posters suggested that they've had a similar experience with recent model Mercedes cars. Some found that the culprit was a DRY gear wheel (the large wheel the starter engages). DRY, meaning NO lubricant left. That the mechanical resistance may cause the computer to shut down the starter operation.

I indicated this to the MB dealership working on my car in West Palm Beach, FL.

They in turn seemed to find that when they would try to replicate the failure, the car was starting flawlessly... which didn't make their search for the cause easier. Luckily, they had witnessed the problem when we brought the car in. Also, I was traveling abroad and did not object to the car staying at the dealership for some weeks.
Anyways, I suggested that if the car was only failing AT TIMES, to me, the culprit could NOT be electronic (there is a CPU governing the starting process right behind the electronic key plug), neither could it be mechanical (things are broken or they are not) but likely to be an electro-mechanical part like a relay. They initially refuted my theory, but in the end, they came back acknowledging that it could indeed be the starter relay which may be failing at times. I gave the green light to have it exchanged and ever since it's been starting happily!

... J-D.

 

My 2006 CLS500 idles so low that it actually stalled when I hit the gas. I usually put in park and give it some gas, but I wonder if this problem will get worse and become unpredictable.

 

This would seem to be a completely different issue than the one being discussed in this thread.

Uneven, low or high idling would primarily seem to be an electronic issue, since idle rpm are constantly being measured and controlled by the electronic controls and sensors.

Usually, in cases like these, one would probably want to look at ALL sensors and sonds. One or several and/or their connections may be failing... sometimes constantly and sadly, sometimes intermittently. Then only, one would proceed to look at the controlling (operating) devices and maybe the different computers (yes, there are more than one).

My first experience with an EFI vehicle was in Ecuador about 15 year back. Not even the Ford dealership could help. I had been "raised" on working on cars with mechanical carburetors and "tuning" them by "ear".
Now THAT thing... I had NO clue whatsoever. I got me the education manuals from somebody who worked at Ford USA and after over a month of reading and marveling and buying an electronic multimeter and two needles to pinch wires, I proceeded as described above and checked every and each sond and sensor... until I found one which did NOT act as described in the book... took it out, brought it to Ford in Quito (they laughed me out, but did sold me the sensor), I put it in and to everybody's including my amazement... blazed away!

I do not recommend you try this on your CLS... these machines have progressed in complexity since Ford's EFI-II. But I think it should tell you that you will want to bring that vehicle to MB and have it checked step by step.

Yes, the computers are supposed to retain "bad" or "wrong" signals or the lack of report from most sensors. The truth is, they don't 100%. It would seem that sometimes, these sensors can give a "semi"-wrong signal and if there are more acting "funny" the whole information flowing between the CPU the sensors and control can become just "distorted" and give you a result like the one you are describing.

Good luck (you know you need it)... J-D.

 

Hi JD

You are also a victime of a lemon Model.I have a CLS 350 06 in my shop with a lot of problems.Can you tell me the fault code when the car dont start?Maybe i can help you.Many times it is a CAN problem.

 

No I am not a victim of a lemon model.
Read refer to the bottom part of my last post above. While it took some time as the failure was intermittent, as I suggested, the starter relay was looked at closer and found to be the culprit (electro-mechanic parts are the most likely to be the when the failure is intermittent.).
Interestingly NO error code was generated... another sign that it could be a relay since they are NOT monitored by the CPU.


I had a lemon MB once, a 1994 CL-500 (W140). I used to call it a movable construction site. I NEVER ever had EVERYTHING working all at once on that car. It spent more time at MB (in Europe!) than on the road.
W140 were problem (lemon) -prone since they had ALL new technology (unlike the previous success models 116 and 126).
Later models do incorporate a lot of the technology initially tried on on W140's but also much of the lessons learned.

... J-D.

 

I will tell you whats happen to the CLS 350 of ouer Customer: 24'000 km= Turbine Sensor Transmission defektive.4500$ ,27'000 km=Evaporator leak. 1500$,30'000 km=Haed light balast left and right defective,Miror adjuster left defective,ect.
This car ist not a Lemon?
But by the way.Is your problem solved?Let me now.

 

I think we may be suffering from some language issues in our communication, dear Rolfsm.
You seemed to suggest that I was a victim of a lemon MB too. I am not.
Which does not mean that YOU may not be.
Given the list of issues, I would be inclined to give you the benefit of the doubt and accept that YOU may indeed be a victim of a lemon MB.
However, let me explain that the term "lemon" has some LEGAL significance in some countries/states, which in most cases is used to describe a RECURRING defect (same defect for 3 or more times after having been "fixed" by the appropriate technical outfit).

I am sorry to hear about your car's issues and hope you will be able to have them all fixed permanently.

As I posted twice now, yes, the one issue I had with my CLS500 has been resolved.



... J-D.

 

had same issue on my CLS 500, turned out to be a crank sensor. it would only happen when trying to restart the car when it's hot. If I let it cool for about 10-20mins, it will restart normally. replaced sensor, so far so good.