ainain

I have S600 2007 W221 sent my ECU for tuning to get better performance.Got it today and when i put it back car wont start dash lights come on but nothing happens when i turn the key to position 3.checked the battery its fine when i switch to position 3 fans start running at full speed!
Any suggestions? ECU? car security?
Thanks in advance

lganski

Welcome to the forum. You will have to have to have a diagnosis done with the star system. Sounds like something was changed that the system does not like.

loungn14

Triple check that you have the electrical connectors on correctly and fully seated until you hear the click

DaveW68

Who did you use for the tune?

ainain

Thanks
I asked a friend to check with star but while connecting to ECU it would say "communication error".

MJ50

either tune file is bad or connection is loose...
yea, who did the tune??

ainain

Thanks I checked i thought that cable and pins correspond in a way that they won't accept the wrong plug but someone else said the same thing as you said so i might be wrong

ainain

ECU photo with connections

DaveW68

Again....who was the tuner?

loungn14

whenever we have seen this with our tuning, it is due to a connector not being properly seated.

I would remove the ecu and slowly reseat it. Check for bent pins.

You should feel a click when the cable is in tight. Gently pull back as well and make sure it is seated.