Faults in a controlled plant often deteriorate the system performance. In severe cases, faults pose a risk of component damage, plant shutdown or even personnel safety. Fault-Tolerant Control (FTC) aims at preventing the escalation of rectifiable faults to serious failure. FTC combines fault diagnosis with reconfiguration methods to manage faults intelligently. This research focuses on FTC for Active Trailer Steering (ATS) systems of Multi-Trailer Articulated Heavy Vehicles (MTAHVs). An observer-based FTC scheme for a MTAHV is developed. To enhance the vehicle dynamics, a H∞ controlled hydraulic ATS system is designed. Fault diagnosis techniques, e.g., Kalman Filter and residual generation, are applied and dynamic performance in high-speed Single Lane-Change (SLC) and double lane-change (DLC) maneuvers is examined. TruckSim package is used to simulate the vehicle performance. Fault scenarios, e.g., actuator malfunction and sensor failure, are explored, and their impact on system dynamics is investigated.