| Pin | Type | Description / Signal type | Connection /
Measuring notes |
|---|
| 1 | A | Positive input signal, microphone | Voice input Microphone |
| | | |
| 2 | | Not used | |
| | | |
| 3 | E/A | Telephone, internal | Eject box |
| | | |
| 4 | | Not used | |
| | | |
| 5 | E/A | Telephone, internal | Eject box |
| | | |
| 6 | E/A | Telephone, internal | Eject box |
| | | |
| 7 | | Not used | |
| | | |
| 8 | | Not used | |
| | | |
| 9 | | Not used | |
| | | |
| 10 | | Not used | |
| | | |
| 11 | | Not used | |
| | | |
| 12 | | Not used | |
| | | |
| 13 | | Not used | |
| | | |
| 14 | | Not used | |
| | | |
| 15 | E/A | I-bus signal line | I-bus connector Telephone connector |
| | | |
| 16 | | Not used | |
| | | |
| 17 | E | Voltage supply terminal 30 | Fuse F74 |
| | | |
| 18 | E | Voltage supply terminal 30 | Fuse F74 |
| | | |
| 19 | A | Negative input signal, microphone | Voice input Microphone |
| | | |
| 20 | | Not used | |
| | | |
| 21 | M | Shield | Shield Microphone |
| | | |
| 22 | | Not used | |
| | | |
| 23 | | Not used | |
| | | |
| 24 | | Not used | |
| | | |
| 25 | | Not used | |
| | | |
| 26 | | Not used | |
| | | |
| 27 | | Not used | |
| | | |
| 28 | | Not used | |
| | | |
| 29 | | Not used | |
| | | |
| 30 | | Not used | |
| | | |
| 31 | | Not used | |
| | | |
| 32 | A | Telephone, internal | Eject box |
| | | |
| 33 | A | Telephone ON signal | Voice input Amplifier Radio |
| | | |
| 34 | | Not used | |
| | | |
| 35 | E | Voltage supply terminal R | K3 Unloader relay terminal R |
| | | |
| 36 | M | Ground | Ground connector |
| | | |
| 37 | A | Positive activation, front loudspeaker | Voice input Amplifier Front loudspeaker |
| | | |
| 38 | A | Negative activation, front loudspeaker | Voice input Amplifier Front loudspeaker |
| | | |
| 39 | M | Shield | Eject box |
| | | |
| 40 | | Not used | |
| | | |
| 41 | | Not used | |
| | | |
| 42 | | Not used | |
| | | |
| 43 | | Not used | |
| | | |
| 44 | | Not used | |
| | | |
| 45 | | Not used | |
| | | |
| 46 | | Not used | |
| | | |
| 47 | | Not used | |
| | | |
| 48 | | Not used | |
| | | |
| 49 | | Not used | |
| | | |
| 50 | | Not used | |
| | | |
| 51 | A | Telephone mute signal | Voice input Radio |
| | | |
| 52 | E | Night light signal | Connector, terminal 58g |
| | | |
| 53 | | Not used | |
| | | |
| 54 | M | Ground | Ground connector |
| | | |