Automotive Service Excellence (ASE) Air Conditioner Certification Practice Exam 2025 - Free ASE Air Conditioner Practice Questions and Study Guide

In the context of an A/C system experiencing high pressure, the most plausible cause is a malfunctioning component that prevents the normal flow and regulation of refrigerant through the system. A broken compressor could lead to a situation where the compressor is unable to create the necessary low pressure in the evaporator for proper refrigerant flow, resulting in high pressure on the high-pressure side of the system.

When the compressor fails, it can lead to refrigerant being trapped, or it may not be able to efficiently compress the refrigerant and circulate it properly, which contributes directly to pressure buildup. Therefore, identifying issues with the compressor is crucial for diagnosing high-pressure conditions in the A/C system.

While other components like a restricted airflow, malfunctioning receiver/drier, and defective expansion valve can certainly contribute to A/C performance problems, they typically have different implications on system pressure. For example, restricted airflow is more likely to lead to low evaporator temperatures rather than high pressure, and a malfunctioning receiver/drier or defective expansion valve can affect refrigerant management but would not usually present as high pressure without other contributing factors.