Anti-Lock Brake Systems (ABS)
How does the select low/high control work on the Haldex Trailer Full Function ABS system?
- It interprets differences in sensed wheel conditions and adjusts between SL (select low) and SH (select high) automatically when the rate of deceleration on one wheel is twice as great as the opposite side wheel, which optimizes trailer stability and stopping distances.
What's the difference (SL vs. SH)?
- When SL is chosen, the ECU responds to sensed wheel with highest rate of deceleration. This prevents lock-up on the wheel that would otherwise lock first resulting in the best overall vehicle stability. With SH, the ECU responds to the wheel with lowest rate of deceleration (least likely to lock-up first), which gives the best overall stopping distance.
Should my tractor ABS unit and my trailer ABS unit be from the same manufacturer?
- Since the systems are independent of each other, have separate ECU's with different ABS logic, different style ABS Valves, and do not communicate with each other during an ABS event; they do not have to be from the same manufacturer. Having a different brand ABS product on your trailer than on your tractor is no different than having different brand air valves on your trailer than on your tractor, which continues to be customary.