As vehicle technology evolves rapidly, the CAN Bus limitations are becoming more apparent. Originally developed in the 1980s, the Controller Area Network (CAN) Bus was designed for simple, low-bandwidth tasks like engine control or window operations. But today’s connected vehicles are essentially data centers on wheels, and CAN can’t keep up.
CAN Bus: A Reliable Workhorse, But Not Future-Ready
The CAN Bus protocol has served the automotive industry well, enabling efficient communication between ECUs (Electronic Control Units). However, the rise of connected mobility, over-the-air updates, advanced driver assistance systems (ADAS), and real-time telematics has exposed the CAN Bus limitations.
Key CAN Bus Limitations in Today’s Connected Cars
1. Bandwidth Constraints
CAN Bus supports up to 1 Mbps. Today’s vehicles exchange gigabytes of data per day, especially with 360° cameras, radar sensors, LiDAR, and V2X communication. High-bandwidth systems like Automotive Ethernet (up to 10 Gbps) are now critical to support:
- Real-time traffic updates
- Remote diagnostics
- Infotainment streaming
- Firmware updates over-the-air (FOTA)
2. Security Challenges and Cyber Risks
CAN Bus lacks encryption and authentication, making it vulnerable to cyberattacks. In contrast, modern architectures support security protocols like:
- MACsec for Ethernet
- Secure boot and encryption
- Intrusion detection systems (IDS)
3. Latency & Prioritization Issues for Critical Systems
ADAS, emergency braking, and autonomous driving features require real-time, low-latency communication. CAN Bus operates on a priority arbitration system that isn’t fast or reliable enough for life-critical tasks. Ethernet-based TSN (Time-Sensitive Networking) is the preferred alternative.
4. Lack of Scalability in Software-Defined Vehicle (SDV)
CAN Bus cannot support the software-defined vehicle (SDV) architecture being adopted by leading automakers. SDV relies on centralized computing platforms, unified data buses, and modular service deployment, none of which are feasible over traditional CAN.
Moving Forward: Ethernet, LIN, and Next-Gen Architectures
Modern vehicles now combine different communication technologies depending on the application:
| Communication Protocol | Speed | Application |
|---|---|---|
| CAN / CAN FD | 1-5 Mbps | Powertrain, basic controls |
| LIN | 20 Kbps | Non-critical components (e.g., seats) |
| FlexRay | 10 Mbps | Time-critical systems (legacy use) |
| Automotive Ethernet | 100 Mbps – 10 Gbps | Infotainment, ADAS, OTA, V2X |
Real-World Impacts of CAN Bus Limitations
For OEMs and Tier-1 suppliers, clinging to CAN-based frameworks hinders product innovation and market competitiveness.
Examples:
- OTA updates may fail or take hours due to limited bandwidth
- ADAS may experience latency due to lack of deterministic communication
- Cybersecurity compliance (e.g., UNECE WP.29) becomes more complex and costly
Conclusion: The Shift Beyond CAN Bus Is Inevitable
The CAN Bus limitations are holding back innovation in connected vehicles. To unlock the full potential of smart mobility, automakers and Tier-1 suppliers must invest in high-bandwidth, secure, and low-latency alternatives like Automotive Ethernet and TSN. The road ahead is clear: it’s time to evolve beyond the CAN Bus.
At Horizon Connect, we provide automotive connectivity solutions customized for the next generation of mobility. Our expertise in in-vehicle Ethernet, protocol stacks, and cyber-secure communication frameworks supports OEMs in transitioning away from legacy systems.
