| Pin | Type | Description / Signal type | Connection / Measuring notes | 
|---|
| 1 | A | Signal Left microphone | Microphone amplifier, left | 
|   |   |   | 
| 2 | A | Signal Right microphone | Microphone amplifier, right | 
|   |   |   | 
| 3 | A | Shield | Microphone amplifier, right | 
|   |   |   | 
| 4 | A | Shield | Microphone amplifier, left | 
|   |   |   | 
| 5 | A | Shield | Handheld microphone, intercom system | 
|   |   |   | 
| 6 | M | Ground Intercom control unit (WSA) | Ground connection X494 | 
|   |   |   | 
| 7 | A | Activation Intercom control unit (WSA) | Handheld microphone, intercom system | 
|   |   |   | 
| 8 | E | Voltage supply terminal 30 | Fuse F64 | 
|   |   |   | 
| 9 | A | Signal, switch off consumer load | General module | 
|   |   |   | 
| 10 | A | Negative input signal, speaker | Handheld microphone, intercom system | 
|   |   |   | 
| 11 | A | Signal Left microphone | Microphone amplifier, left | 
|   |   |   | 
| 12 | A | Signal Intercom control unit (WSA) | Handheld microphone, intercom system | 
|   |   |   | 
| 13 | A | Activation Pneumatic speaker | Connector X3250 | 
|   |   |   | 
| 14 |   | Not used |   | 
|   |   |   | 
| 15 | A | Signal Intercom control unit (WSA) | Handheld microphone, intercom system | 
|   |   |   | 
| 16 | E | Signal Rear left door contact | Rear left door contact switch | 
|   |   |   | 
| 17 | E | Signal Rear right door contact | Rear RH door contact switch | 
|   |   |   | 
| 18 | E | Signal Driver's door contact | Driver's door contact switch | 
|   |   |   | 
| 19 | E | Signal Passenger's door contact | Passenger's door contact switch | 
|   |   |   | 
| 20 | A | Signal Intercom control unit (WSA) | Handheld microphone, intercom system | 
|   |   |   | 
| 21 | A | Positive input signal, speaker | Handheld microphone, intercom system | 
|   |   |   | 
| 22 |   | Not used |   | 
|   |   |   | 
| 23 | A | Signal Intercom control unit (WSA) | Handheld microphone, intercom system | 
|   |   |   | 
| 24 | A | Signal Right microphone | Microphone amplifier, right | 
|   |   |   | 
| 25 | A | Telephone mute signal | Radio | 
|   |   |   | 
| 26 | M | Ground Pneumatic speaker | Connector X3251 | 
|   |   |   |