Necessary preliminary tasks:
Release screw (1).
Lever out cable clip (2).
Remove cover (3).
Fold back cover (1).
Release nut underneath. Remove positive battery cable from positive battery connection point.
Unclip positive battery cable (1) from brackets (2) at rear of engine block.
Remove protective cap (1) and release nut underneath.
Release nut (2) on starter.
Disconnect positive battery cable (3) from alternator and starter motor. Feed out positive battery cable (3) and remove.
NOTE: Reassemble the vehicle.
Check stored fault messages.
Delete fault memory.
BMW X3 Service & Repair Manual > Electrical: Preheating relay
REPLACING PREHEATING CONTROL UNIT (N47D20 O1)
Necessary preliminary tasks:
Switch off ignition.
Remove INTAKE SILENCER HOUSING .
Release positive battery cable (1) from clamp.
Release expanding rivets (2).
Remove rear acoustic cover (3).
Detach connector (1) from preheating contro ...