I01�High-voltage�Components
11.�Cooling�the�Electrical�Machine
Components
166
The�electric�coolant�pump�has�a�power�of�80 W�(Manufacturer:�Bosch).�The�coolant�pump�is�activated
by�the�EDME�control�unit.�For�this�purpose,�the�coolant�pump�and�the�EDME�control�unit�are
connected�via�a�direct�line.�The�electric�coolant�pump�can�be�activated�at�varying�power�by�pulse-
width�modulated�signals.�The�voltage�supply�of�the�coolant�pump�is�effected�via�terminal�30B.�The
installation�location�of�the�coolant�pump�is�at�the�rear�right.
The�expansion�tank�is�located�in�the�space�below�the�engine�compartment�lid�on�the�left.�There�is
no�electrical�level�sensor�installed�in�the�expansion�tank.�But�there�is�the�following�special�feature
to�be�noted�for�Service:�A�loss�of�coolant,�for�example�due�to�a�leak,�in�the�cooling�system�is�not
identified�directly�due�to�the�lack�of�an�electrical�level�sensor.�Instead,�in�the�event�of�coolant�loss
the�temperature�of�the�cooled�components�(electrical�machine,�electrical�machine�electronics,
convenience�charging�electronics,�range�extender�and�the�range�extender�electrical�machine
electronics)�rises�above�the�normal�operating�range.�In�this�case�the�power�of�the�electric�motor�is
reduced�and�a�corresponding�Check�Control�message�is�issued.�The�Service�employee�must�check
the�following�fault�causes�during�troubleshooting:
•
Loss�of�coolant,�e.g.�by�a�leak
•
Coolant-air�heat�exchanger�blocked
•
Electric�fan�does�not�work�or�is�restricted
•
Coolant�pump�does�not�work
•
Coolant�lines�or�connections�damaged
•
Components�to�be�cooled�faulty�(electrical�machine,�electrical�machine�electronics,
convenience�charging�electronics,�range�extender�electrical�machine,�range�extender�electrical
machine�electronics).
If�excess�temperature�is�displayed�in�the�cooling�system�of�the�electric�motor,�then�this�may�have
several�causes,�including�also�the�loss�of�coolant.�Therefore,�during�troubleshooting�all�components�of
the�cooling�system�must�be�checked�systematically.
The�familiar�mixture�of�water�and�antifreeze�and�corrosion�inhibitors�in�BMW�vehicles�is�used�as�a
coolant.
When�filling�the�cooling�circuit�of�the�electric�motor�use�the�special�tool�for�vacuum�filling�according�to
the�repair�instructions.
Perform�a�bleeding�after�filling�the�cooling�circuit,�as�well�as�after�replacing�components�in�the�cooling
circuit.
For�the�bleeding�the�cooling�circuit�for�the�electric�motor�in�the�I01�follow�the�same�procedure�as
for�conventional�vehicles.�There�is�a�Service�function�in�the�diagnosis�system�for�the�activation�of
a�bleeding�procedure.�This�consists�of�appropriate�activation�of�the�electric�coolant�pump�(varying
engine�speed,�defined�duration).�This�bleeding�procedure�can�also�be�activated�without�the�diagnosis
system.�The�following�procedural�steps�must�be�carried�out�here:
1
Connect�the�charging�plug�to�the�vehicle
2
Switch�on�terminal�15�(only�ignition,�no�driving�readiness)
