merc e250 w210 edc light

[markheaney2]

i hope someone can help me i have a w210 e250 diesel 1996 the car quite often will not start because when you switch the ignition on the edc light does not come on when it comes on about every 10th attempt the car starts fine i have already bypassed the immobiliser about 6 months ago so that is now not the problem what controls the edc light and why does it not come on more often than not any help would be appreciated

 

[alexander patie]

does it ever cut out? could be a faulty K40 relay, i have seen this on your model car.

 

[markheaney2]

merc e250 edc light

thanks for the reply once the car is running it will never cut out until the next time you want to get it going where is the k40 relay if i can find it i will replace it just to make sure

 

[markheaney2]

merc e250 edc light

after checking all wiring disconecting many connections pulling fuses putting back in taking out ecu checking connections and putting back the car seems to be starting ok again with the edc light coming on every time the problem now is the central locking and electric windows wont work the car is doing my head in people keep mentioning the k40 relay where is this and what would make the windows and central locking not work thanks in anticipation i served my time as a mechanic but i am lost when it comes to electrics

 

[alexander patie]

k40 relay is in the module case under the bonnet. this has a black plastic cover with 4x screws and is at the passenger side back at the bulk head.

for central locking and windows i suggest you disconnect the battery for 1 min and then reconnect and try again. if this cures it for a while at least then get back here and tell us.

 

[markheaney2]

merc e250 edc light

to carry on with this saga the electric windows, sunroof, heated rear screen and central locking are still not working i have again disconnected the battery for a few hours i have checked every connection every fuse has been taken out and checked no luck what controls all these things am i missing something

 

[alexander patie]

ok, lift the rear seat base and have a look next to the battery. you will find a foam clad control unit - this is the pse unit and does many things. have a look for any signs of damp, disconnect the plugs and check for corrosion - see anything? obviously you have already checked ALL the fuses in the 3x fuse boxes?

 

[markheaney2]

merc e250 edc light

yes under the back seat i noticed that this is where all the fuses are for the items that arent working i have checked all the wires going into this fuse box there is no damp and the wires all look brand new i havent lifted the foam from the door locking unit i will do that in the morning but if damp had got into this unit would it not have blown one of the fuses in the fuse box anyway i will check all the wires running to this pump thanks for you help

 

[markheaney2]

merc e250 edc light

i have now disconnected all the wires to the black box next to the battery that controls the central locking there are no signs of damp wire corrosion etc it all looks brand new i have put it all back in and still not working is the central locking,electric windows,heated rear screen,electric sunroof dont know what to try next i have now disconnected the battery i will leave it all day then try again tomorrow how long do the electrics ecu etc take to lose all memory

 

[markheaney2]

merc e250 edc light

i have now checked everything again and cannot find anything out of place still not working are the following electric windows,electric sunroof heated rear windscreen central locking please has anyone got any ideas

 

[markheaney2]

merc e250 edc light

does anyone have a list of all the things that the k40 relay operates