Key problems

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jupiter2step

Active Member
Joined
Feb 2, 2011
Messages
135
Location
Derbyshire
Car
S211 E220 CDI Avantagarde
Twice in the past week my key has failed to start the ignition. Fan, radio, battery, etc. all works, but when I turned fully to start the engine... nothing. Not a thing - not even a click. The starting motor was not even trying to turn, and there was no error registered either. Took key in and out of ignition, still nothing. Finally got out of car, locked and unlocked door, and tried again. Started first time. Did the same thing yesterday when problem occurred again, and it worked once more.

As long as it continues to start I'm not too worried. My fear is that some day the lock/unlock thing won't work and I'll be left stranded.

It has never happened with my wife's set of keys - we use both keys interchangeably.

Any ideas? Seems to be locking / unlocking the car fine so I'd doubt if there is a battery problem.
 
Sorry for bumping this old thread. The same problem happens to me about once every couple of months, then resolves itself.

Happened again this morning, only it took a few additional attempts to start it. The only thing that was different on this occasion was I did get a message saying "convenience functions unavailable". Possible battery issue?
 
Any ideas? Seems to be locking / unlocking the car fine so I'd doubt if there is a battery problem.


From what I remember the key will start the car even if the battery (in the key) is dead.
Maybe it powers up from the car?


Sorry can't help you out any more myself
 
Electric key problems

Twice in the past week my key has failed to start the ignition. Fan, radio, battery, etc. all works, but when I turned fully to start the engine... nothing. Not a thing - not even a click. The starting motor was not even trying to turn, and there was no error registered either. Took key in and out of ignition, still nothing. Finally got out of car, locked and unlocked door, and tried again. Started first time. Did the same thing yesterday when problem occurred again, and it worked once more.

As long as it continues to start I'm not too worried. My fear is that some day the lock/unlock thing won't work and I'll be left stranded.

It has never happened with my wife's set of keys - we use both keys interchangeably.

Any ideas? Seems to be locking / unlocking the car fine so I'd doubt if there is a battery problem.
.

Hi Guys

I too am experiencing very similar probllems with my 2000 C180 (W203). Started about a month a ago, it would take several presses on the electric key FOBS (I have two) before the car would lock/unlock or turn the ignition, Batteries in the Fobs are ok as both LED's flash when pressed. I had the car battery tested which was ok but as it was the original MB unit i decided to change it at a cost of £120 GBP and even bought a battery charger incase it turned out to be a drain somewhere. Everything worked fine for about two days then SAME PROBLEM but getting worse, harder and harder to get the door locks and ignition working. I had the car put on a diagnostic machine which showed NO PROBLEMS. Having searched many MB forums I've found out this is a VERY common problem with all Merc electric keys and can usually a variety of things including a faulty PSE PUMP (can anyone tell me where this is located)?.

Once the car starts and has run for half hour or so, everything is ok and door locks and ignition work first time until it's left sitting for more tha 3 hours or so.. I know there no power issues with either the car battery or the FOB's and as the problem is so intermitent it can't be a fuse or it would not work at anytime. Disconnecting the car battery for an hour and reconnecting seemed to help at first but even that now is hit or miss. I'm now leaving the car unlocked at night in the garage in case it's the alarm/immobiliser draing the battery but that's has not helped. Does anyone know how to start this car without relying on the ecectric key (as once it's started and run everything is ok until it's left sitting) is it possible to activate the central locking without the key as it sometimes decided to arm the alarm for no reason. The manual key opens the door but that sets the alarm off and ignigtion still won't turn.

We are at the point now where the car is unreliable and cant be left sitting for any length of time

Can SOMEBODY HELP solve this without me having to spend hundreds more Pounds at my local STEALERSHIP.

PLEASE HELP AS I'M LOSING MY SANITY WITH THIS CAR.
 
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Hi Jupitor, welcome to my world which is your worst nightmare...............please see my post in reply to your's, any advice would be appreciated mate.
 
Hi Dinomax

Sorry to hear of your woes. Have booked the car in for a diagnostic tomorrow. In my case, the problem is just with the ignition, no bother (as yet) with the locks.

Will let you know if I get any news back from dealer.
 
To my (admittedly inexperienced) eye, this sounds more like an immobiliser/security problem.

Will the key, when it is in the ignition switch, turn to the 'start' position, or does the switch prevent the key turning that far?
 
We had very similar with our 203 shortly after it was new in 2000. Sometimes the keys worked, sometimes they didnt. Sometimes would unlock the car, sometimes not. Sometimes unlock but not start. Sometimes do nothing. The dozy dealer insisted it was the keys so 2 new keys ordered. Surprise surprise no better. Eventually we left it there for 2 weeks while they worked out what to do. In the end it had new ignition switch/control and security system. Fortunately all under warranty. I have since heard that these faults were pretty common on early 203s. I know how you feel. It was all very frustrating.
 
Will the key, when it is in the ignition switch, turn to the 'start' position, or does the switch prevent the key turning that far?

In my case, I am able to turn it alright - dash lights, etc. come on as normal. But when the glow plug light goes out and try to turn on the engine, that's where it all goes wrong.
 
So it's not a mechanical problem with the switch. The key turns to the start position and springs back as normal, but nothing happens?

Do the dash lights dim at all when the start position is engaged?
 
Starter motor. Try pushing +12v straight into the starter motor trigger wire when this happens.
 
In my case, I am able to turn it alright - dash lights, etc. come on as normal. But when the glow plug light goes out and try to turn on the engine, that's where it all goes wrong.

Hi,
You have said that you have had a diagnostic, but was that with STAR (MB OEM diagnostic software) as generic code readers generally won,t be able to read all the monitored systems.
As the key always let's the steering lock go I would say your EIS is ok and its only the locking and engine not turning over that's the problem allbeit intermittently I would suspect a SAM fault, 203s I believe suffered from this, I did think this could be a faulty PSE pump but the fact the engine is,nt turning over would seem to indicate Not.
Maybe someone else could offer an opinion.
 
So it's not a mechanical problem with the switch. The key turns to the start position and springs back as normal, but nothing happens?

Do the dash lights dim at all when the start position is engaged?

That's correct. I think the lights did dim, but can't be 100% certain to be honest.


Hi,
You have said that you have had a diagnostic, but was that with STAR (MB OEM diagnostic software) as generic code readers generally won,t be able to read all the monitored systems.
As the key always let's the steering lock go I would say your EIS is ok and its only the locking and engine not turning over that's the problem allbeit intermittently I would suspect a SAM fault, 203s I believe suffered from this, I did think this could be a faulty PSE pump but the fact the engine is,nt turning over would seem to indicate Not.
Maybe someone else could offer an opinion.

My indy has a Bosch reader rather than Star. Was to go there this morning, but I wonder should I rebook a diagnosis with another who has the Star system?

Could you explain what a "SAM fault" is? Sorry, am not good with many technical terms!
 
If the lights do dim, then come serious current is being drawn, and you can take it from that that the starter is likely getting current, but is not moving, i.e. it is stuck (or otherwise being mechanically prevented from turning the engine over).

If the lights don't dim, then there is no significant current draw, and you can take it that the starter is not being asked to do anything. Then you're back to looking at SAMs, modules, etc.
 
Went to another Indy with Star this morning. Nothing showed, but he feels certain problem is with the EIS. These don't come cheap (have to be ordered and programmed in Germany apparently), but I've told them to go ahead. Fingers crossed....
 
Just to chuck in an unhelpful curve ball. I have 2 keys with my W203. One, perfect. The second, locks and unlocks, but rarely starts the car. I ordered a spare, as I couldn't run the risk of the "good" key dying.
Both my good keys are fine, and I just don't use the duff key. Keys aren't indestructible, and £230 is for a replacement is steep, but c'est la vie. .
 
We had very similar with our 203 shortly after it was new in 2000. Sometimes the keys worked, sometimes they didnt. Sometimes would unlock the car, sometimes not. Sometimes unlock but not start. Sometimes do nothing. The dozy dealer insisted it was the keys so 2 new keys ordered. Surprise surprise no better. Eventually we left it there for 2 weeks while they worked out what to do. In the end it had new ignition switch/control and security system. Fortunately all under warranty. I have since heard that these faults were pretty common on early 203s. I know how you feel. It was all very frustrating.

Thanks for the info
 
i have a simmerlar problem with my s210 found if i straighten the wheels it will then start its just like the old fashion steering lock give it a wiggle to start
 
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Well i have the same trouble as some of you guys here. I'm able to turn the key, all the lights work, I wait till the pre heater (diesel) light goes out then turn the key to the right and nothing happens. This problem occurs 2 to 3 times a week and when it happens i need to try 2 to even 7 times till the engine starts. I get the key out of the ignition, place it back in turn it, wait till pre heating light goes out and turn it to the most right position to start.
Anyone found a solution yet?
 

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