clk500 w209 starting problem
 

hi guys
having a problem with the clk500 w209 2004 with start and go button not starting
the mechanic who is working on it now stuck a bit the car is accident damaged small damage just to front slam panel and radiator nothing serious.
The key locka and opens the doors opens the ignition but when you turn to start nothing at all
no codes, checked with sds, the mechanic managed to start it with some tool from front SAM unit and he connected a wire to one of the relay in the unit and when that wire is earthed the car starts from the key if not earthed then no the mechanic confused a bit now and suspects some wires are damaged underneath the SAM unit.
a tip from the pros here would really help and appreciated

Do you have KeylessGo with the start/stop button on top of the gearshift? If so, does the key work in the ignition? Also, do you have more than one key and is this a problem with all keys?

Hi there!
Yes it does have the keyless go and the key and the button opens the ignition but when you turn the key start up it does nothing not cranking at all.
Only one key and the key starts the engine if you Earth the negative wire that the mechanic connected to starter relay it is I guess.
Also the gear box oil level is too low can that trigger some safety options for engine not start?

Excuse me! My bad the doesn't start neither with key or the start button

OK, that could be a bad starter relay. The relay is "S" in this diagram:

http://benzbits.com/w203/FrontRelays.pdf

I doubt it's a fuse, but check #52 & #52:

http://benzbits.com/w203/FrontFuses.pdf

Yes exactly to the same relay the mechanic connected the wire that has to be earthed so is he trying to make it big job to rip me off simply for the bad relay or can it be something else?
When you earth that wire from that relay the car starts from the key

My guess is that he is just jumping out the relay.

And what does that mean please? Is it bad relay or bad earthing somewhere?
Thanks

Bad relay.

https://cimg8.ibsrv.net/gimg/www.mbw...31197fb61e.jpg

Here what he did to get it started<br/>
That brown wire that he connected to relay has to be earthed to get it started from the key

I ordered the relay will see tomorrow
Hope that will sort it out.

I really think it's the relay and not a bad ground within the SAM/fuse panel.

Tried new relay from the dealer with no luck
Replaced the Sam unit no luck there either.

someone who has the same issue says his local garage diagnosed the problem is in ecu
do these ecu goes bad?

The ECU can go bad, but if the jumper wire allows the engine to start and run, I doubt that's it.

Solved
The mechanic says he flashed the gearbox ecu and engine ecu with the updated software and it started from key now
Really confused with why the gearbox and engine were running fine after it started from the wire? Maybe the mechanic not saying everything?))))

I'm clueless! But glad it's running now.