12 42 530 Replacing battery positive lead (between starter motor and alternator) (M54 / M56)

Read fault memory. Switch off ignition.

Observe safety instructions for handling vehicle battery.

Remove front underbody protection. See 13 32 051 REPLACING FUEL FILTER (M54)

Observe instructions for disconnecting and connecting battery. Refer to 12 00... Instructions for disconnecting and connecting battery .

Disconnect battery negative lead from battery and lay to one side.

Remove suction filter housing. See 11 61 050 REMOVING AND INSTALLING INTAKE AIR MANIFOLD (M54)

Release nut and disconnect battery positive lead (2) from alternator.

Installation: 

Tightening torque. Refer to ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUE .

Fig 1: Disconnecting Battery Positive Lead From Alternator

Courtesy of BMW OF NORTH AMERICA, INC.

E46 only: 

Remove reinforcement plate on front axle support. 18 00 020 REMOVING AND INSTALLING COMPLETE EXHAUST SYSTEM (M54)

If fitted:

Remove vacuum reservoir for exhaust flap.

Unscrew nut (1).

Installation: 

Tightening torque. Refer to ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUE .

Disconnect battery positive lead (2) from starter motor. Remove battery positive lead.

Fig 2: Disconnecting Battery Positive Lead From Starter Motor

Courtesy of BMW OF NORTH AMERICA, INC.

E39 only: 

Fig 3: Detaching Battery Positive Lead From Holder

Courtesy of BMW OF NORTH AMERICA, INC.

Release screw connection of battery positive lead (1) (floorpan). Release nut on starter motor (3).

Installation: 

Tightening torque. Refer to ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUE .

Detach battery positive lead (1) from holder (2).

• - Read out fault memory of DME control unit
• - Check stored faults
• - Rectify faults
• - Clear fault memory