makaka

Hello

I got a problem with my cls 55 the car is not starting (not even cranking) , i can't hear the pump priming and i am getting abs and esp error , the fan is running at full speed i already checked all fuses and they are in good state, battery is new ,
i checked many thread here in this forum and other some says it is a bad ECU , i took it out for inspection and it look clean nothing burned or damaged (did also quick multimeter check its look ok).
Is there any scheme that can help something like car power sequence so i can check step by step what is wrong with the car ,
i am new to the car world but i am used to soldering and electronic repairs

nd-photo.nl

Did you perform a proper scan using STAR/Xentry? If so, what did it point out?

machild

The high fan is an indication there is a general fault occurring. As suggested, a good full scan, preferably using Star, is warranted.

makaka

thanks , i just figured out the issue it is broken pin on the ecu due to water damage , i soldered it and the car started fine ,
if documentation is right it was the pin 16 (sensor ground 2).
strongly enough the car with this broken pin has same behavior as without ECU connected

machild

Confirming power(s) and ground(s) on any control module is one of the first diagnostic steps when chasing down an issue. Good find and repair. Welcome to the forum.