Unit installation

NoteReference NoteReference
Control unit installation positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Bus topology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installation positions of fuses and relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Overview
Convenience electrics
Control unit for power management J644 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Access and start authorisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Immobiliser and component protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
External lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Control unit in dash panel insert J285 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Control unit for on-board power supply J519 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Control unit 2 for on-board power supply J520 . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Central control unit for convenience system J393 . . . . . . . . . . . . . . . . . . . . . . . . 55
Door control units J386 - J389 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Control units for seat adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Infotainment
Multimedia interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Antenna systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Control unit for front information J523. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Sound systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Available telephone systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
The Self-Study Programme provides information on the fundamentals of design and function of new vehicle
models, new vehicle components or new technologies.
The Self-Study Programme is not a Workshop Manual!
Specified values serve only to make the information easier to understand and relate to the software version
that was valid at the time the Self-Study Programme (SSP) was created.
For maintenance and repair work, please make sure to use the current technical documentation.
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