help electrics on c230k estate

[bj merc 230k estate]

i have just bought a c230k estate with minor front panel damage,the drivers window was left open and the ign. switch had water in it (not a normal type key one of the ones with infrared in the end),i cant get the windows ,wipers,indicators or mirrors to work but they will fold in!!the dealer says i might have multiplex wiring and it will need a new switch.at 300plus vat plus coding.can anyone help,i have checked all fuses and relays as much as poss. could all this be down to this switch? it does start and run although sometimes it wont accept the key at all.the electric steering lock doesnt work at all, help please

 

[television]

I do not know how long you have had the car,but with water damage you can have random faults all over the car, some of the ECUs are partly sealed as are the SAM units,the water or moisture can stay on a panel for a long time. Until you are sure that they are dry it will be impossible to say what is happening.

Malcolm

 

[Blobcat]

Malcolm as the drivers window was open do you think that the water has got into the EIS?

 

[bj merc 230k estate]

hi malcolm thanks for the reply,what does a sam unit do and do you know where they or it is?

 

[television]

Malcolm as the drivers window was open do you think that the water has got into the EIS?

there is two parts to this, If yes it should not start at all, but it does start sometimes !!!! the Whole system is linked by the CAN BUS, this is a parrallel pair of wires the connect every system on the car, by this I mean windows, doors etc,these are all wired in parrallel together. Water anywhere in the system knocks out everthing else.

Its like say a 5v supply going down on a circuit board,and you may have 50 IC's on the panel, the 5 volts goes to every IC and the only way to solve it is to lift the 5v supply pin on every IC until you come to the faulty one.


The same goes for the car, most of our cars have the seat and window memory and other ECU's in the doors. Until they are all dry, you will never work it out.

Malcolm

 

[bj merc 230k estate]

is there anyone in wales that could code in a new switch(eis) or can a s/hand one be recoded?
It's a dealer job I think, however I would take apart the door and the steering binnacle to trace the water corrosion.

 

[Blobcat]

It's a dealer job I think, however I would take apart the door and the steering binnacle to trace the water corrosion.

 

[bj merc 230k estate]

i did strip down the eis unit and water had been in it,but i suppose the damage had already been done,i did spray with wd40 and blow out with an airline carefully,that stopped it buzzing and made it start better

 

[television]

is there anyone in wales that could code in a new switch(eis) or can a s/hand one be recoded?
It's a dealer job I think, however I would take apart the door and the steering binnacle to trace the water corrosion.

If the door is dry on the inside and all of the ECU's are as well. I f they are wet they must be placed on a radiator for a couple of days, there must not be any moisture in the connectors, this can stop the car from starting.

If the car starts somtimes there is nothing wrong with the EIS switch, they cost £400 plus fitting and they cant be re coded, a new one would be coded to match the car, but as I have said, anything wet will stop the car from starting, just one drop of water on the CAN connectors will do this. Example a car will not start if the drivers seat is faulty or wet.

Malcolm

 

[bj merc 230k estate]

thanks didnt realise it was so sensitive to moisture i will have a good look around for anymore traces of water ingress tomorrow. drivers seat works ok,but i better start in the drivers door first,what is a can connector,and what does it look like,or is it any electical connection

 

[Ultymate]

IF you do locate your can-bus wiring don't go probing the wiring looking for voltage as I believe it only carries digtal signals around the car:? and you can do expensive damage by so doing!

 

[television]

thanks didnt realise it was so sensitive to moisture i will have a good look around for anymore traces of water ingress tomorrow. drivers seat works ok,but i better start in the drivers door first,what is a can connector,and what does it look like,or is it any electical connection

CAN wires are a thin pair of wires running to all of the unit that go to the X connectors scattered around the car, where they go into a X connector they have 2 pin plugs coloured green/green-white,for one system. Or brown/brown-black

Malcolm