DTC code P0600 OBD2 indicates a malfunction in the wiring link between the Engine Control Module (ECM) and one of its supporting control modules, i.e. the ECM has lost control over one or more of the actuator modules. Generally, vehicles have up to 18 actuators controlled by the ECM. For this, a Control Area Network (CAN) is used, this is a series of cables connected from the ECM to the controllers.
The controllers operated by the ECM are responsible for controlling most vehicle functions. If the P0600 code has been set, it is because of a loss of control communication that has occurred over one or more of these modules during eight consecutive starts.