Hi i am from sweden and have a problem with my Astro, service engine soon is on and i have found out witch code it is, and the code is CODE 43 electronic spark control.
what is that and is it something i can fix myself

Welcome!
Code 43 is for the knock sensor or sensors
Most likely you will need to replace the sensor and the connector that goes with it.
Torque the sensor to 14 ft/lbs....no more, no less