1) I have a 2002 Mercedes Benz CL 500 coupe.
2) September 25th 2008 – Ordered a new key from Mercedes Benz because old one cracked
3) Immediately after receiving the key – trunk release stopped working on the key and on interior driver door
4) Within 1 week – The car would not disarm until I pressed the button on the key 3 or 4 times(only during the first start of the day – during the rest of the day this was not an issue)
5) Each morning it would take a little longer to disarm the car than it did the morning before. (again this problem was exclusive to the first start of the day) within a couple of weeks it would take up to 10 minutes pushing the button before the car would disarm and unlock the doors.
6) I replaced the key battery but the problem continued.
7) I did not have time to take the car in at the time so I began using the blade key to open the door. I would then jump in the car, put the electronic key in the ignition, and start the car so the alarm would turn off. Sometimes it would take a couple of tries before I could get the key to turn(my screaming car alarm in the morning made me very popular with the neighbors …)
8) At about the beginning of November, I started parking my car inside my garage at night so could leave it unlocked and not worry( this worked great for a while because I could just get in my car in the morning, start it, and not have to disarm)
9) Soon after, I had problems starting the car every morning without fail. I would stick the key in the ignition but it would not turn. I would take the key out and put it back in the ignition a couple of times. Then, as if something would release, I would be able to turn the key and the car would start right up. (Again, this problem was only during the first start of the day. During the rest of the day there was never a problem starting or disarming the car at all.)
10) Gradually, over the next couple of weeks it took longer and longer each morning for the ignition to release and let the key turn(still only in the morning)
11) The week before I had the car towed to the Mercedes dealer because it would not start at all, I would finally get the car started in the morning and then it would get stuck in park. I would then have to turn the car off and restart it again and then it would shift. This seemed strange because I had just replaced the gear shift assembly before all of these problems started.
12) Eventually, after going through all of that every morning, - On December 21, 2008 I did not drive my car at all that day – On December 22, 2008 when I went to start the car it took an hour before I could get the ignition to let me turn the key and when it did turn, the car did not start at all.
13) I had it towed to the Mercedes dealership to diagnose the problem. They said they thought it was the electronic ignition that needed to be replaced. I asked if they ran a diagnostic. They said that nothing came up but their opinion was that it was definitely the ignition.
14) So I had the ignition replaced and it was $1,200.
15) Yesterday, when I picked the car up from the dealership, the passenger window was down and would not roll up. I asked the service advisor why this was happening. He said, the battery voltage was very low and the battery needed to be replaced. He also said, I would probably have many false warning lights going off on the dash and some of the functions of the car might not work(i.e. The electric windows , the seats, power mirrors, etc.) until the battery was replaced. They also said, that they charged the battery while they had it but I need a replacement ASAP.
16) I replaced the battery that night.
17) My passenger window still does not roll up and my mirrors do not work and the doors will not lock or unlock but the car does start(at the very least,… the thing starts)
18) Back on December 22nd when I had the car towed, I thought that the problem was with the new key, possibly being defective (which they say they tested and it was fine) or maybe it had something to do with the, just replaced, gear shift assembly. (They were sure it was the electronic ignition.) I never considered the battery to be an issue because everything was so gradual.
19) Now, I am curious, as to whether it was just the battery slowly going bad and just barely supplying the voltage needed to open the doors in the morning after sitting all night. Then when started, the alternator would charge the battery just enough to get me through the rest of the days arming and disarming and engine starting.
20) Also, after sitting for those 2 days in December (see #11 above) without being started, the battery may have discharged enough in those 48 hours to not work at all. That would explain why it wouldn’t start that day….right???
21) My question – Is it likely that I did not need the ignition replaced and the problem was simply the battery?
22) Am I wrong in my thinking here??? Did I just get screwed?
23) I am taking the car back in on Monday morning and I’m not sure what to say to the service department at the dealership. .….Has anyone ever had their battery die in a CL500 with similar symptoms? How do I get to the bottom of this and find out if I really needed that electronic ignition replaced or not? Any advice?

 

Hi.
Wow.
You appear to be a very tolerant and organised individual.
I never cease to be amazed by these "horror" stories.

Unfortunately I don't believe I can give you a definitive answer but will share my thoughts.

MB's (and other cars with electronics) are very sensitive to voltage.
Low voltage causes systems to shut down or report faults.
Sometimes this is recorded as a DTC Diagnostic code but not always.

As I have said so many times on this site one of the first things to check on an MB is battery voltage.
A battery which has gone below 12.5 volts is SCRAP even if recharged.
OK it may stagger on for a while, even quite a long time, but eventually it will go WITHOUT ANY warning.
The battery becomes unreliable due to internal chemical changes.

Now maybe your battery was down but not sufficiently to cause a problem when the electronic systems first boot up.
However when you crank the vehicle the voltage can dip to below the electronics threshold and anything can happen.
Low voltage usually hits the ABS, ESP systems since the way in which these systems operate are governed by Safety Critical criteria. Processors working at below operating voltage are unreliable...but you have not declared that these systems reported any such warning.

The key turn solenoid MAY BE voltage sensitive since it MAY need a good voltage in order to provide sufficient energy to remove the mechanical locking pin. Just a thought.,

It is extremely unlikely that multiple faults occur at exactly the same time however your well documented symptoms suggest faults in more than one system ./ component.
I note that everything started with a new key which now appears to be working OK.

In fitting a new EIS (Ignition switch) they would have had to reprogramme the key again in order to match it to the new EIS.
Maybe the key wasn't programmed correctly the first time and changing the EIS resolved the problem due to the reprogramme rather than the EIS itself.
Your guess is as good as mine!

However the problem then shifted to the key not turning.
This involves the EIS (mechanical solenoid in the EIS) as well as a signal from the CSL Change speed module.
Now the CSL module has been changed. Why I wonder?

Now the next bit brings more confusion.
The CSL wouldn't come out of Park. This is likely due to your Brake light switch or some issue with the CSL/gearbox module.
However, the EIS is also implicated since it acts as a gateway for a number of these electronic systems.

Now the wild card!!
Windows that don't rollup, seats that don't move etc

Now you don't say whether this problem is resolved and everything is now working normally.

If things are still not working correctly it would appear that there is some (odften difficult to locate) short on the CAN (digital highway) which all feeds into the EIS.
Windows mirrors etc etc are all controlled digitally.

If however everything is now working OK I suspect that the EIS may have been the cause of the "short".
Alternatively the EIS/key programming could have been the problem BUT that you also have some other yet to be located short on the CAN. This would suggest that maybe the EIS was OK.

Although multiple faults rarely occur at the same time I suspect that it was as a consequence of the age of the battery (you don't state how old it was. "Normal" life expectancy (3 or 4 years dependent upon type) + the heavy demand due to the cold weather.

I wonder if they still have the displaced EIS??

If indeed you still have the problems with the windows etc. then I tend to agree that the EIS was most probably OK and that it was a programming problem.

The CAN doesn't like cold weatgher which promotes cabin moisture which in turn leads to these difficult to find, and often self correcting, faults.

If indeed you are still experiencing the window / mirror problem I would suspect the window / seat control switch has got wet whilst the door is open due to rain or snow.
I suspect that this COULD also be the cause of the CAN short and if so then I suspect that the displaced EIS MAY STILL OK.

Make sense?

Stuart

 

Late addition:

Don't suppose you left the key in (or near) the ignition when you parked the car in the garage?

If so the vehicle computers won't go to sleep and this will drain the battery.

This could be the cause of the battery "failure"

Another suspect has to be the PSE Pneumatic Security unit which is a known cause of CAN short.
Unplug the white multi connector on this and see if you get window control back.

My motto is to NEVER change components until you understand the problem and can turn the problem ON/OFF.
It takes time, patience and logic.

Dealers just swap out boxes as recommended by SDS Star Diagnostics and charge the customer for them.
The alternative is excessive labour charges which may cost even more!!!

These problems are NOT MB specific.
They are as a result of the ever increasing technology present in cars and the lack of understanding of how they work.
Just wait till we get "Collision Avoidance".

Good Luck.

Interested in your feedback.

Stuart

 

1) the ABC light on the dash has been coming on for the last 8 months. I took it to the dealership 2 times and they said nothing was wrong with it.2) the key - I thought this was the problem but they said it was programed correctly(The ABC light was coming on long before I got the new key, leads me to believe it was the voltage issue and not the key) (3) The gear shift assembly - had it replaced just before all of this started because the car was stuck in park. They said it was not the break light switch because they could hear it release. (#4) The battery age - It looks like the origional mercedes battery to me, I have only owned the car for about 2 years and this is the first time I replaced it (#5) I read somewhere that the dealership required by law in Californiato return the removed parts tothe car ownerif requested....do you know if thats true? The work was just done last tuesday and I picked the car up and brought it home on Friday night(#6) I replaced the battery last night andthe window,mirrors and door locks still do not work.

 

Concerns me that they were guessing at this one, they said it didnt come up on the diagnostic but they were sure the ignition was the issue. Thought every function of the car was recorded.......???Shouldn't something have come upwhen they hooked it up to the computer?So what do you think I should say to the dealership on Monday?
Thanks for all the great information! I can't tell you how much help you have already been...............................Matt

 

P.S. Never leave the key in the car.

 

Your car is 2002 so won't be the original battery. Usually have date written on them.

So you didn't have an ABS / EPS warning. In which case I don't think that battery is the main problem.

You haven't replied re whether you left keys in the ignition when parked inside?

I live in UK so do not know whether parts have to be kept by the garage in Calif etc,.. A "good" garage usually offers you the opportunity to view the parts so you have confidence they have been changed etc. Many people don't care. Others do!

Quote "........because they could hear it release." Could hear what release. The CSL solenoid?
If so it should have moved out of park.
I don't understand the logic here.

Brake light switches are a known source of problem.

How to tackle the dealer. Mmm.
I usually give everybody the benefit of the doubt. Most people are honourable but of course.....

My reaction is that I'm appalleds that the dealer returned the car to you with known problems and especially with the window down.
They warned you about all the possible warnings but that misses the central point.
How could you be expected to use the car in winter with the window down?
Maybe there is a bit of the story here that i don't have.
If the battery has indeed gone below 12.5 volts I don't understand why they didn't ring you, and subject to your agreement, change it.

I am increasingly coming to the conclusion (from the limited data available to me) that you have a "classsic" CAN short due to moisture.

New Key,
New EIS
New CSL module
Brake light switch confirmed OK
New Battery and I assume charging confirmed as OK.
No codes set! Are we sure about this?? I assume they are using SDS Star and not a simple OBDII scanner. With the battery down etc I would have expected all manner (maybe irrelevant) codes to have been set.
Get them to provide you with an SDS Star Diagnostics Quick Test hard copy report taken after you return the car to them. This only takes a few minutes. we then have more data to go on.
Maybe they can't give you such a report because they don't have the equipment.
This is a genuine MB dealer I take it.

Assuming all these changes were done correctly it certainly narrows the field.

Problem is finding a CAN short is not a quick and simple task.
Its a process of disconnection at predetermined access points.
Any unit linked to the CAN can be at fault.
Intermittent problems (like moisture) are especially difficult to deal with.

I would have the PSE and seat/mirror controls high on my list of suspects BUT I would not change these ***** nilly.
Simplest approach is to temporarily exchange them and if no improvement is achieved return them to the AS IS condition.
Only the garage can do this and even then they are not supposed to break Quality Assurance seals on parts in stock.

Anything more to add?

Stuart

 

Hi, Matt

Only just seen your answer re key in ignition.

A little more to add...

Quote: "The ABC light on the dash has been coming on for the last 8 months. I took it to the dealership 2 times and they said nothing was wrong with it."

Lights and codes aren't set without something being wrong. Period!

It is true that they may not be able to find a cause but that doesn't mean there isn't a problem.
Voltage irregularities often cause this type of problem.

Finally. Yes the Quick Test Diagnostics accesses all systems and reports on all codes that have been set since the memory was last cleared. On an S Class you will be amazed just how many codes can be stored. Very often these codes are as a result of a failing battery etc and can be ignored BUT the codes are set for a reason. You can tell an enormous amount from this history. If they cleared the memory when they were working on the car (since they had the computer connected to change the EIS....can we be sure they had the computer connected?? any faults currently logged must therefore be since they were cleared.

My approach would be to get them to do this check with you present and to see whether this gives new direction to the discussion we have already had.
May be lots of codes but since you changed the battery may have been lost. Get them to clear them if present and then go for a short drive to see what new is recorded as a result..

I don't think that they have intentionally ripped you off but I'm beginning to wonder how competent they are. incidentally the Quick Test report includes date and VIN identification numbers so that you can see that the test was run on your car. The VERY FIRST THING the test does is to report battery voltage!!

I had a test done and was advised all was OK.
I don't think they even looked at the report which I always request when I have the car smog tested.
The recorded battery voltage was 10.5 volts!!!
Bottom line they hadn't connected the leads to the battery correctly.

I'll be interested in what the dealer proposes doing. Since they have already had your money for the EIS I would expect them to sort the problem without further expense...but I don't like giving anybody my money.

 

So if I get a copy of the of the diagnostic and it says the battery volts were low(which I'm sure it will because on my reciept for the service under "Recommendations" it says, "BATTERY WEAK" what do I say to them?
If I tell them I think this was due to the battery and not the ignition, they are probably going to say that they charged the battery first and the ignition still wasn't working. Then what? There has got to be a way I can find out "for sure"what was really going on. I plan on asking for my money backon Monday because I really believe it was the battery that created this. I don't think they did thisto rip me off(at least I hope not) I think they were either lazy anddidn't really diagnosecorrectly or they just didn't care. Probably both judging from the condition the car was in when I picked it up..
So, what factsdo I say to them to support my arguement, that this was the battery? Better yet, what sort of proof can I ask them for that shows it was the ignition?Is there some code in the report I should look for? Receipt shows a report number, so there must be a copy of it on file somewhere. The receipt also says"erased all codes" after changing EIS. Then it says "Tested system again" "OK now" "working as designed" How is that possible if the battery wasn't working right and the window wasn't working and the mirrors and door locks were also not working?
By the way it was a certified Mercedes Benz dealer.
Thanks again,
Matt

 

Yep,

Report before clearing is key. I suspect that they won't have it but maybe they do.

Diagnostics is not as straightforward as it may seem.
It is quite possible for there to be a fault and no code set BUT that doesn't mean there isn't a fault.

The report lists DTC (fault codes) for each system on the car starting with the engine / trans and then the chassis (ABS), body (Air Con) electrical systems.

You raise the correct questions.

How can it be as designed and this and that don't work!

get the report, put that question to them, ask them what they are going to do next and then ask for your money back and see where it takes you.

Order is important. IMHO.

Stuart