Activating the service mode

The service mode can be activated within the first 8 seconds after switching on the radio unit. This is achieved by pressing and holding the "m" button (after 1.5 seconds, the SCAN mode is activated, the m button should not be released until the service test mode is entered. SN * * * * * * will be shown). The radio will then automatically switch to service test mode. Switching off the radio deactivates the service mode.