Among the electronic driving aids were a semi-automatic transmission, an anti-lock braking system (ABS), a traction control system, and active suspension. The 1993 Williams FW15C model featured all of these aids. This trend was ended by the FIA when it outlawed these aids for the 1994 season, considering that they reduced the importance of driver skill to too great a degree. Bi-directional telemetry was also forbidden, which was soon reinstated as the FIA found it too hard to analyse the engine programmes in order to search for hidden code that could be found breaking the rules.