A: Crown can bus communication failure:
1. The fault caused by the automobile power supply system: the working voltage of the automobile electronic control module is generally 10.5-15.0 volts. If the working voltage provided by the automobile power supply system is abnormal, some electronic control modules will temporarily work abnormally, resulting in poor communication of the entire automobile CAN bus system.
2. The link failure of the car CAN bus system: when the communication line is short-circuited, broken or the physical property changes, resulting in attenuation or distortion of the communication signal, many electronic control units will not work normally, and the CAN bus system will not work. 3. The node failure of the automobile CAN bus system: the node is the electronic control module of the automobile CAN bus system, so the node failure is the fault of the electronic control module. Including software failure, that is, there are defects or conflicts in the transmission protocol or software program, which makes the communication of the automobile CAN bus system confused or unable to work, such failures usually occur in batches; Hardware failure is usually the electronic control module chip or integrated circuit failure, resulting in the car CAN bus system can not work properly. Note: In the process of measuring resistance, it should be noted that: first disconnect the wiring of the vehicle battery, wait for about 5 minutes, and then measure after all capacitors in the system are discharged, because the resistance of the internal circuit of the control unit will change.