this car is really giving me hell lol, I first thought it was the starter then I jumped it direct and it cranks just not with the key, checked all fuses in SAM module front and rear and all are good except front SAM fuse 53 was blown, replaced it and when I turn ignition on it blows the fuse. I put a test light to it, end to positive and tip of light to fuse and seems to be grounded out somewhere, I'm stumped on this one, any help would be great help..

 

Hi Sam and welcome to the forum! Before spending any money on parts; have the codes read to see where the issue is coming from.

 

Everytime I turn ignition to position 2 fuse blows 25amp fuse. Lost not sure which way to go car is a 2006 C350 sport. Maybe front Sam unit? Anyone with past knowledge help would be appreciated, very desperate at this point. Can't communicate with ecu for fault codes.

 

 

 

Has anyone confirmed a fix on this I have 07 c230 same issue blows fuse 53 as soon as I turn key to on position I’ve checked wiring all looks ok I’m leaning towards ecm smells burnt also

 

I have same exact issue and here is what I found - ECU board inside of metal housing has shorted to housing right beside one of the white insulator strips & exactly where a capacitor is located on board, to me this is a factory defect, not enough insulation to isolate voltage flowing across back of ECU board, my board is toast and just a matter of time until a replacement ECU does the same thing, It sucks having to take apart a new ECU to insulate behind the board but it's the only way to end this problem,

 

I had the same problem. Turned out to be that the #2 ignition coil had shorted out. I replace the ignition coil and the fuse and it solved everything. The #2 ignition coil also communicates with the ecu somehow. Hope this helps.