Most automotive electronic devices are connected to various grounding points on the body through the wiring harness. It is generally believed that the impedance of the body is much smaller than the impedance of the wiring harness. Accordingly, the following rules must be followed as much as possible for the grounding design:
The length of the grounding wire should not be too long. If the length cannot be adjusted for a long wire harness, in order to reduce conduction and radiation interference, it is possible to consider adding filtering to the wire harness. A more convenient method is to socket a suitable ferrite magnetic ring.
The ground wire of the integrated power electronic appliance can only be nailed to the body with at most one connection;
The grounding of the safety system should be arranged separately from other electrical grounds, even double grounding, and the functional ground and electrostatic ground of the airbag ignition device should be separated;
The ground of the sensor cannot be grounded through the same connection nail as the ground of the load (heater, motor, etc.) and the ground of parts with large current and voltage gradient (ignition coil, fuel injector, fan, power controller, etc.);
The electronic ground of each control module should be separated from the ground wire of the high-power inductive load;
For high-power LIN (Local Interconnect Network) nodes, the signal ground and functional ground should be separated; the master node and slave node of the LIN network use the same ground point;
The grounding of the infotainment system is star-shaped and cannot be grounded together with other types of equipment;
The same system can share the ground to avoid crosstalk between different systems.