What step should be taken if the disabled train is a Comeng while being assisted?

Setting the trip and pilot valve is the correct action to take when assisting a disabled Comeng train. The trip and pilot valve are crucial components in the train's braking system and vital for ensuring that the train can be safely moved or re-energized. When a train is disabled, these valves help to reset the braking system and enable communication with the other train if there is an assist operation in progress.

Ensuring that the coupler is set electrically is not the primary concern in this scenario, as electrical coupling does not directly address the mechanical and safety checks needed for a disabled train. While setting the reverser to neutral is critical for the safe operation of diesel or electric trains to avoid unintended movement, it does not resolve the immediate issues associated with a disabled train. Raising the pantographs is generally more relevant for restoring power; however, if the train is disabled, ensuring the valves are correctly set takes precedence for safety and operational integrity.