Trailer Electronic Brake Systems (EBS – ABS) Explained

What is EBS and ABS on semi trailers? How they work together, safety features, system components, legal requirements and compatibility with truck ECUs.

📌 Published on 2025-11-06 | ✍️ Semi Trailer News Editorial

Image: Trailer EBS & ABS system layout

🔹 What Are ABS and EBS?

ABS (Anti-lock Braking System) prevents wheel lock-up and maintains steering control. EBS (Electronic Braking System) delivers faster, electronically controlled braking force.

🔹 Key Safety Advantages of EBS

Shorter stopping distance
Synchronized braking with tractor
Rollover prevention through load sensing
Improved stability on slippery surfaces
Electronic brake pressure modulation

🔹 Main Components of Trailer EBS

Electronic Control Unit (ECU)
Wheel Speed Sensors
Brake Modulator Valves
ISO 7638 Electrical Connector
CAN-BUS Data Link

🔹 ABS vs EBS: What is the Difference?

Feature	ABS	EBS
Brake response	Slower	Fast, electronic
Stability control	Basic	Advanced
Diagnostics	Limited	Full CAN codes

🔹 Legal Requirements

ABS mandatory worldwide for trailers
EBS required for high-GCW combinations in EU
ISO 7638 mandatory for EBS

🔹 Compatibility With Truck

EBS requires a tractor equipped with EBS-compatible ECU communication. If not available, the system reverts to ABS-only mode.

🧮 Wheel Speed Converter (km/h ↔ m/s)

EBS and ABS calculate wheel slip using real-time wheel speed data. Use this converter to evaluate braking events and sensor readings.

Speed Converter km/h m/s

Conclusion:
EBS dramatically improves braking performance, stability, and safety. It is now standard on modern European trailers and essential for heavy transport operations.