49 CFR §238.445

1. (a)Each passenger train shall be equipped to monitor the performance of the following systems or components:
   1. (1)Reception of cab signals and train control signals;
   2. (2)Truck hunting;
   3. (3)Dynamic brake status;
   4. (4)Friction brake status;
   5. (5)Fire detection systems;
   6. (6)Head end power status;
   7. (7)Alerter or deadman control;
   8. (8)Horn and bell;
   9. (9)Wheel slide;
   10. (10)Tilt system, if so equipped; and
   11. (11)On-board bearing-temperature sensors, if so equipped.
2. (b)When any such system or component is operating outside of its predetermined safety parameters:
   1. (1)The train operator shall be alerted; and
   2. (2)Immediate corrective action shall be taken, if the system or component defect impairs the train operator's ability to safely operate the train. Immediate corrective action includes limiting the speed of the train.
3. (c)The monitoring system shall be designed with an automatic self-test feature that notifies the train operator that the monitoring capability is functioning correctly and alerts the train operator when a system failure occurs.