What aspect will not be displayed if a train is operating with a malfunctioning ASC?

When a train is operating with a malfunctioning Automatic Speed Control (ASC) system, it is important to understand the implications this has on the signals being displayed to the train crew. The ASC system is designed to ensure that the train operates at safe speeds based on the signals it receives from the track. If the ASC is malfunctioning, it may not correctly interpret or display vital information about the train's speed restrictions, especially regarding the signals that represent the absence of restrictions or clear conditions.

In the context of signals, a "Clear Signal" indicates that the track ahead is clear for the train to proceed at its maximum authorized speed. If the ASC is malfunctioning, it may fail to display a clear indication, thus not allowing the engineer to proceed without caution. This situation could lead to safety concerns, as the crew may not be aware of the actual conditions of the track ahead.

The other aspects, such as Absolute Approach, Clear Medium, and Low Speed Limit, may still be communicated effectively through alternative safety systems or existing signaling infrastructure even if the ASC does not function properly. Therefore, the specific inability to display the "Clear Signal" is critical, as it directly affects how the train crew can assess the operational status and prepare for safe travel.