What is the purpose of HVIL connectors in EVs when performing service?

• A. They store energy for emergency power.
• B. They ensure HV circuit remains de-energized when a disconnect is opened or a connector is disconnected.
• C. They indicate the HV system status with a light.
• D. They provide mechanical support.

Answer: (B)

HVIL is a safety interlock that guarantees the high-voltage circuit stays de-energized whenever you open a service disconnect or separate a high-voltage connector. When the service panel is opened or a plug is disconnected, the HVIL path breaks, signaling the vehicle’s high-voltage control system to trim power by opening the battery contactors. This prevents any high voltage from remaining on exposed components, protecting technicians from electric shock during maintenance. It isn’t about storing energy, signaling with a light, or providing mechanical support; those roles are handled by other systems. So the main idea is that HVIL keeps the HV system off when you’re working on it.