| Pin | Type | Description / Signal type | Connection / Measuring notes
 | 
|---|
| 1 | A | Telephone ON/OFF | Keypad handset | 
|  |  |  | 
| 2 |  | Not used |  | 
|  |  |  | 
| 3 | M | Ground | Ground point | 
|  |  |  | 
| 4 | E | Voltage supply terminal 30 | up to 1996_09 Fuse F65 as of 1996_09 Fuse F57 | 
|  |  |  | 
| 5 | E | Terminal R | Unloader relay terminal R | 
|  |  |  | 
| 6 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 7 |  | Not used |  | 
|  |  |  | 
| 8 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 9 |  | Not used |  | 
|  |  |  | 
| 10 | A | Telephone mute signal | Radio | 
|  |  |  | 
| 11 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 12 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 13 |  | Not used |  | 
|  |  |  | 
| 14 | M | Negative input signal, microphone | Microphone | 
|  |  |  | 
| 15 | A | Positive input signal, microphone | Microphone | 
|  |  |  | 
| 16 | E | Voltage supply terminal 30 | up to 1996_09 Fuse F65 as of 1996_09 Fuse F57 | 
|  |  |  | 
| 17 | M | Ground | Ground point | 
|  |  |  | 
| 18 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 19 | A | Positive input signal, speaker | Front loudspeaker | 
|  |  |  | 
| 20 | M | Shield | Shield | 
|  |  |  | 
| 21 |  | Not used |  | 
|  |  |  | 
| 22 |  | Not used |  | 
|  |  |  | 
| 23 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 24 | E/A | Motorola-internal | Keypad handset | 
|  |  |  | 
| 25 | E | Negative input signal, speaker | Front loudspeaker | 
|  |  |  |