How to enter a four digit Becker radio code

Becker Mexico cassette and CD radios (the CC and CD models and the Mexico Pro CC, CD and MD), and the Becker radio with ten station buttons fitted to Mercedes in the early 1990s.The radio Mercedes fitted in the early 1990s, drawn from Mercedes' manual.
Type it and every step uses your own digits. It stays on this page.
Turn the key to the first position and switch the radio on. The display shows CODE.
Every step
Checked against Becker's operating guides for the 1432 and Mexico radios.
If it locks
Three wrong codes bring up WAIT. On the Mexico, leave the ignition and the radio switched on for 60 minutes; three more wrong codes block it for another 60. On the early 1990s Mercedes radio the wait is 15 minutes with the radio left on, and after the third round it becomes 24 hours. What each lockout screen means
A Mexico 7948 or Mexico Pro 7930?
Those take a five digit code. Five digit Becker steps
A Mercedes radio?
Mercedes fitted several radios. The Audio 10 and the keypad radio take a five digit code and have their own steps. The Becker radio sold as a Mercedes accessory from 1999 takes four digits like this one, and its wait is 60 minutes. See the Mercedes radios
Not this one? Other Becker radios
Mercedes Citan radioCitan with six number buttons
Mercedes Audio 10 CDCD radio with no number buttons, serial AL
Mercedes Audio 10 with keys 1 to 4Cassette radio with keys 1 to 4
Mercedes radio with a number keypadNumber keypad on the right of the radio
Becker radio with a five digit codeTraffic Pro, Grand Prix, DTM, Mexico Pro