What are the causes of CAN bus failure?

[MacIsabel]

CAN bus failure causes: 1. Faults caused by the vehicle power supply system: If the operating voltage provided by the vehicle power supply system is abnormal, it may cause certain electronic control modules to malfunction temporarily, leading to poor communication in the entire vehicle CAN bus system; 2. Link faults in the vehicle CAN bus system: Short circuits, open circuits, or signal distortion in the communication lines can result in multiple electronic control units malfunctioning, rendering the CAN bus system inoperable; 3. Node faults in the vehicle CAN bus system: Nodes are the electronic control modules in the vehicle CAN bus system, so node faults refer to faults in these modules, including software faults such as defects or conflicts in the transmission protocol or software programs, which can cause communication chaos or failure in the vehicle CAN bus system.

[DelHope]

I used to work at a 4S dealership and frequently encountered CAN bus failures. The most common causes were aging wiring or physical damage, such as cracked cable insulation from prolonged vehicle use allowing rainwater to seep in and cause short circuits, or rodents chewing through wires. Loose connectors are also prevalent, especially in chassis or engine bay plugs that weren't securely fastened, leading to signal interruptions during vehicle vibration. Software issues shouldn't be overlooked either – ECU programming errors or protocol conflicts during system upgrades without proper matching can cause complete network communication failures. Electrical interference is another hidden danger, where nearby high-voltage equipment or improperly installed aftermarket electromagnetic devices can generate disruptive signals. I recommend regular wiring harness inspections, particularly before winter and rainy seasons, to avoid travel disruptions.

[ErinFitz]

My beloved car once had a CAN bus issue. It happened on the highway when the dashboard suddenly went black, which really startled me. Looking back, it might have been caused by water splashing on the connectors during a car wash last year, leading to corrosion and poor contact, or perhaps loose wiring connections. Unstable current after modifying the audio system, which interferes with bus signals, is also a common trigger. Additionally, faults in the ECU module or sensors can cause communication errors, leading to multiple vehicle system failures, such as engine control and ABS malfunctions. Unstable power supply, like battery issues or alternator failure, can also be a contributing factor. Regularly check connector tightness, avoid unnecessary modifications, and use an OBD tool to scan diagnostic codes for early detection.

[McOlive]

I have worked in automotive electronics for many years, and the main causes of CAN bus failures are divided into hardware and software. On the hardware side, issues include cable breaks or wear, connector corrosion, insufficient module power supply, etc.; on the software side, protocol inconsistencies or configuration errors can lead to conflicts. Environmental factors such as high temperature and humidity accelerate component aging. Once a failure occurs, systems like vehicle lights and braking may be affected. During diagnosis, prioritize checking physical connections, then use scanning tools to analyze network data packets.