2 days ago i couldnt start the engine and (SLK 200 kompressor)i would like to ask you about the possible reasons related to this problem
I think its strange because there was no electricity at all when i turn the key to the first click position. No lights no sound.(Normally you can hear the pump noise and see the lights at the first level before the igniton)
And as you can guess at the second click it didnt work too
I tried maybe 5 or 6 times , (engine wasnt cold , i was back from a friends house and decided to go out somewhere else).
I could detect the problem if the ignition had failed (like grrrr grrr grrr then stop s)but as i mentioned there was no reaction at all.
I asked for help and with my 2 neighbours we tried to start the engine by pushing the car.(i dont know what you name it in english we do it when the battery is flat so i describe with details )

I turned the keys on position I shifted to 2 while i keep my feet on the clutch (becomes neutral ), released the handbrakes , they pushed the car and at a certain speed i relased the clutch suddenly while the contact key was and it didnt work again, because there was no electric current.

I decided to quit and waited for half an hour then it worked at the first attempt.
I checked for many times and there was nothing wrong with the ignition.

Yesterday while waiting at the traffic lights the engine suddenly stopped, and i tried to start the engine.Unfortunately same sh* happened. It was totally gone. You can imagine the horns and peoples reaction in the rush hour.

I dont know why the engine stopped there , btw my car has a manual transmission and i am sure that it wasnt my fault .
I believe that there is something wrong with the contact key mechanism. There is no sign of a weak battery or fuel injection problems.

Some people claims that there is something wrong with the electronical brain and the system goes off to the malfunction phase which needs to be resetted. This happened only two times but i dont feel comfortable with the car now, its again a ghost problem which is ready to surprise me.

Well before visiting the service I would like to know the possible reasons.Could you pls help me about this problem.

Thank you

 

I think you called it yourself. Start by checking the key switch.

Since you said you had no lights, it's probably not the engine ECU or 'brains'. Lights and other accessories are not controlled by the ECU, and would not be affected if it malfunctioned. The key switch provides power to many circuits.

 

Thanks for your interest , as you said i will focus on the keyswitch.

 

Either the switch or the security device. The key has a passive transponder inside that is coded to match the computer. I would assume the electronics for the security are still part of the ignition switch, so the switch is definitely the right place to start.

 

Brian ,

I remembered that i accidentally dropped the key from the balcony.(3rd floor ) down to the ground a couple of months ago.
As it is also a part of the system , before going to the service i took some risk and decided to use the spare key.(well its not a rational way but at least i wouldnt burn the whole house for a rat )

Nothing happened yet, it has been more than 2 weeks.It seems like its ok with the spare key.
Of course i dont wanna come back here with some terrible accident news.

I would like to know a simple key can cause this kind of problem...
any relation between? or not at all?