6thSense

Hello guys, I have a problem with my family Benz 143ps prefacelift from about a year, but the problem gets worse and worse. Sometimes, when it is cold it simply wont start. The key unlocks the car, the steering and switches the car to pre-start, but when you turn the key to actually start the car it just does absolutely nothing. When the car starts there is no problem after that whole day. When it is warm also it starts with no sign of a problem whatsoever.

From what i've read on the forums the problem is in the SAM module? ( The module that recognizes the key and allows the immobilizer to start the car). But i am no expert at all, so i would like your opinions and recommendations.
Thank you.

Carsy

Just wondered how old the battery is ? After the first start it may become sufficiently charged to be OK during the day.

Could also be the starter motor. Give it a sharp tap to see whether it will start when cold.

6thSense

We've tried to start the car with cables when it was not firing up, didn't work. The car has been acting like that from awhile, maybe a year or so. Sometimes there the problem do not show up for a few months then two times in a row etc. Today it started like a charm for example, yesterday no such luck. :/

Carsy

Time for an auto electrician to load test the battery & check the startermotor before you are stranded.