This document provides instructions to access a hidden service test menu on the Connect Nav+ unit. It describes pressing specific buttons in a particular order - "Setup", then "Connect" 4 times quickly, then "Enter" - which will cause a "Service" button to appear. Selecting this allows testing and ensuring various modules, speakers, antennas, and GPS/GSM systems are functioning properly. The second part of the document provides meanings for channel options in the service test menu, including checking system errors, interior and exterior temperature sensors, air vents, display, temperature flap settings, and potentiometer values.