BMW X5: Alternator With Drive And Mount

REPLACING ALTERNATOR BELT PULLEY

Special tools required:

• 12 7 110

Remove and install alternator drive belt.

Depending on alternator type, grip shaft with:

• hexagon socket
• multi-tooth socket or
• Torx socket wrench

Release nut with special tool 12 7 110.

Installation:

Tightening torque, 12 31 2AZ / 12 31 3AZ.

Fig. 37: Identifying Special Tool 12 7 110

REPLACING ALTERNATOR BELT PULLEY (WITH OVERRUNNING CLUTCH)

Special tools required:

• 12 7 120

Remove and install alternator drive belt.

Grip alternator shaft with:

• internal serration

Release nut with special tools 12 7 120.

Installation:

Tightening torque: 12 31 3AZ.

Fig. 38: Special Tools (12 7 122) And (12 7 121)

CHECKING ALTERNATOR (BSD)

Necessary preliminary tasks:

• Correct connections on charged battery
• Correct connections on alternator and starter motor
• Good ground connection between engine and body
• Tensioned ribbed V-belt
• Read out DME/DDE fault memory.

NOTE: The alternator with BSD interface can communicate with the engine control unit (DME/DDE).

The alternator can identify various faults.

BSD alternator can be recognized by the plug connection on the alternator.

Connect diagnosis tester.

• Function selection
• Complete vehicle
• Drive
• Voltage and current regulation
• Voltage and current generation
• Alternator
• Follow instruction in diagnostic program

Oscillogram for a fault-free alternator:

Fig. 39: Identifying Waveform - Fault-Free Alternator

Oscillogram for a faulty alternator:

One phase interrupted.

Repair/exchange alternator.

Fig. 40: Identifying Waveform - Faulty Alternator (1 Of 6)

Interturn fault.

Repair/exchange alternator.

Fig. 41: Identifying Waveform - Faulty Alternator (2 Of 6)

Open circuit in negative diode.

Repair/exchange alternator.

Fig. 42: Identifying Waveform - Faulty Alternator (3 Of 6)

Short circuit in positive diode.

Repair/exchange alternator.

Fig. 43: Identifying Waveform - Faulty Alternator (4 Of 6)

Open circuit in positive diode.

Repair/exchange alternator.

Fig. 44: Identifying Waveform - Faulty Alternator (5 Of 6)

Open circuit in exciter diode.

Repair/exchange alternator.

Fig. 45: Identifying Waveform - Faulty Alternator (6 Of 6)

Assemble engine.

Check function of DME/DDE.

REMOVING AND INSTALLING/REPLACING ALTERNATOR (N62)

Necessary preliminary tasks:

• Disconnect battery negative lead.
• Remove SUCTION FILTER HOUSING.
• Remove ELECTRIC FAN with cowl.
• Remove alternator DRIVE BELT.

Disconnect plug (3) from alternator.

Unscrew nut (1).

Lay B+ line (2) to one side.

Fig. 46: Identifying Plug And Nut

Release screws (1).

Remove alternator (2).

Installation:

Modify guide pulley (3) to new alternator (replace if necessary).

Fig. 47: Identifying Alternator, Guide Pulley And Screws

Check DME (alternator) for correct operation.

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