a) Turn the ignition switch to the "ACC" or "ON" position.
b) Press the "POWER" key, then press the "FM 1" and "MEDIA" keys simultaneously for 2 seconds or more.
Note: To move to the next code, press the "SEEK" key.
1 - "FM 1" key,
2 - "MEDIA" key,
3 - "SEEK" key,
4 - "POWER" key.
c) The fault codes are given in the table "Radio fault codes".
The original article is on MazBook
d) To complete the self-diagnosis mode, turn the ignition switch to the "OFF" position.
2. Erasing codes.
a) Enter self-diagnosis mode.
b) Press the "POWER" key, without releasing the "POWER" key, press the key "AUDIO CONT" for 2 seconds or more.
1 - key "AUDIO CONT",
3 - "ROWER" key.
c) To complete the self-diagnosis mode, turn the ignition switch to the "OFF" position.