BMW F12 2011 Technical Training Manual page 50

F12￿Chassis￿Dynamics
5.￿Steering
Index
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Terminal￿15N
Terminal￿30
Terminal￿30F
LIN-Bus
The￿BCU￿charges￿the￿auxiliary￿battery￿with￿the￿assistance￿of￿a￿DC/DC￿converter.￿It￿monitors￿the￿state
of￿charge￿in￿the￿auxiliary￿battery￿and￿the￿cable￿shield￿that￿encloses￿the￿24￿V￿cable￿which￿is￿installed￿in
the￿vehicle￿floor.
It￿switches￿the￿relay￿in￿the￿separator￿that￿integrates￿the￿auxiliary￿battery￿into￿the￿circuit.￿The￿EPS￿is￿on-
ly￿supplied￿with￿24￿V￿once￿this￿relay￿has￿been￿switched.￿If￿a￿fault￿develops,￿the￿EPS￿can￿also￿be￿oper-
ated￿using￿12￿V.￿If￿no￿fault￿develops,￿the￿relay￿in￿the￿separator￿is￿switched￿from￿terminal￿15N.
The￿following￿excerpts￿from￿the￿system￿wiring￿diagram￿show￿the￿various￿switching￿situations￿and￿the
auxiliary￿battery￿charging￿operation.
46
Explanation
Electric￿Power￿Steering￿(EPS)
Digital￿Motor￿Electronics￿(DME)
Junction￿box￿for￿the￿power￿distribution￿box
Junction￿box￿electronics￿(JBE)
Integrated￿Chassis￿Management￿(ICM)
Separator
Charging￿controller￿for￿auxiliary￿battery￿(Battery￿Charge￿Unit￿[BCU])
Luggage￿compartment￿power￿distribution￿box
Auxiliary￿battery
Intelligent￿battery￿sensor￿(IBS)
Battery
Battery￿power￿distribution￿box
Steering￿column￿switch￿cluster￿(SZL)
Instrument￿panel￿(KOMBI)
Central￿gateway￿module￿(ZGM)
Ignition￿(after-run)
Terminal￿30
Terminal￿30,￿fault-dependent
Local￿interconnect￿network￿bus