Method for Operating a Communications Accessory Device

A communications accessory device for a motor vehicle having an ignition variable between an ON-state and an OFF-state, wherein the device comprises:

• a permanent power supply line input,
• an ignition sense line input;
• and
• a control logic coupled with both inputs;
• and
• wherein the control logic detects a power supply status of the power supply line input and of the ignition sense line input and, in response thereto, sets a wrong installation status flag at least when a power supply status LOW of the power supply line input is detected while a power supply status HIGH of the ignition sense line input is detected.

A communications accessory system wherein the system comprises:

• an electrical supply circuit in a motor vehicle;
• a communications accessory device including:
• a permanent power supply line input from the electrical supply circuit;
• an ignition sense line input from the electrical supply circuit;
• a control logic in the communications accessory device coupled with the permanent power supply line and the ignition sense line, wherein the control logic detects a power supply status of the power supply line input and of the ignition sense line input and, in response thereto, sets a wrong installation status flag at least when a power supply status LOW of the power supply line input is detected while a power supply status HIGH of the ignition sense line input is detected;
• and
• an indicator, wherein the indicator is activated when the wrong installation status flag is set.