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WDS BMW Wiring Diagram System - X5 E53
A18 Amplifier
Plug connector overview
Number
X-pin, colour
Description
X18771 15-pin, black Plug connector A Amplifier (Top Hifi)
X18772 18-pin, black Plug connector B Amplifier (Top Hifi)
X18773 26-pin, blue Plug connector C Amplifier (Top Hifi)
X01183 1-pin, metal Plug connector D Amplifier (Top Hifi)
Pin assignments at plug connector X18771
Pin
Type
Description / Signal type
Connection /
Measuring notes
1 A Positive signal, subwoofer speaker 1 Subwoofer speaker
2 A Positive signal, subwoofer speaker 2 Subwoofer speaker
3 A Positive activation, rear left loudspeaker Left rear speaker
4 A Radio ON/antenna signal Radio
5 E Negative activation, rear right loudspeaker Right rear speaker
6 E Negative signal, subwoofer speaker 4 Subwoofer speaker
7 E Negative signal, subwoofer speaker 3 Subwoofer speaker
8 E Terminal 30 Fuse F72
9 E Negative signal, subwoofer speaker 1 Subwoofer speaker
10 E Negative signal, subwoofer speaker 2 Subwoofer speaker
11 A Touring Left rear speaker
12 A Touring Right rear speaker
13 E Positive signal, subwoofer speaker 4 Subwoofer speaker
14 E Positive signal, subwoofer speaker 3 Subwoofer speaker
15 M Terminal 31 Ground point
Pin assignments at plug connector X18772
Pin
Type
Description / Signal type
Connection /
Measuring notes
1 Not used
2 E Negative signal, low frequency Transceiver/charging electronics
3 Not used
4 Not used
5 E/A I-bus signal line Connector X18344
6 Not used
7 Not used
8 E Negative activation, front right loudspeaker Radio
9 E Negative activation, front left loudspeaker Radio
10 Not used
11 A Positive signal, low frequency Transceiver/charging electronics
12 Not used
13 E Telephone mute signal Transceiver/charging electronics
14 Not used
15 E Telephone ON signal Transceiver/charging electronics
16 Not used
17 E Positive activation, front right loudspeaker Radio
18 E Positive activation, front left loudspeaker Radio
Pin assignments at plug connector X18773
Pin
Type
Description / Signal type
Connection /
Measuring notes
1 A Positive activation, front left woofer Left front speaker
2 M Negative activation, front left woofer Left front speaker
3 Not used
4 M Negative activation, front right medium-range speaker Right front speaker
5 A Positive activation, front left mid-range speaker Left front speaker
6 Not used
7 Not used
8 Not used
9 A Positive activation, front right medium-range speaker Right front speaker
10 M Negative activation, front left mid-range speaker Left front speaker
11 A Positive activation, rear right medium-range speaker/tweeter Right rear speaker
12 A Positive activation, front right tweeter Right front speaker
13 A Positive activation, front right woofer Right front speaker
14 A Positive activation, front left tweeter Left front speaker
15 M Negative activation, front left tweeter Left front speaker
16 M Negative activation, rear left medium-range speaker/tweeter Left rear speaker
17 Not used
18 Not used
19 A Positive activation, rear left medium-range speaker/tweeter Left rear speaker
20 Not used
21 Not used
22 Not used
23 Not used
24 M Negative activation, rear right medium-range speaker/tweeter Right rear speaker
25 M Negative activation, front right tweeter Right front speaker
26 M Negative activation, front right woofer Right front speaker
Pin assignments at plug connector X01183
Pin
Type
Description / Signal type
Connection /
Measuring notes
1 E Central locking signal Audio frequency CD changer