Mazda RX-8 Workshop Manual page 3157

4. Verify that "PASSWD CLEAR" is displayed in the information display.
5. To stop the on-board diagnostic test mode, turn the ignition switch to the LOCK position.
With Car-navigation Unit
Starting procedure
1. Turn ignition switch to ACC or ON position.
2. Turn the audio power to ON.
3. While pressing the POWER/VOLUME switch, simultaneously press the TUNE/AUDIO switch for
1 s or more.