12 31 020 Removing and installing or replacing alternator (M52, M52TU, S50US, S52, M54, M56)
Necessary Preliminary Tasks:
- Read out stored fault messages.
- Switch off ignition.
- Follow instructions for disconnecting and connecting battery, refer to 12 00... INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY .
- Disconnect and cover battery negative terminal
- Remove suction filter housing, refer to 13 71 000 REMOVE AND INSTALLING INTAKE FILTER HOUSING (M52TU, M54) .
- Remove fan clutch, refer to 11 52 020 REMOVING AND INSTALLING/REPLACING FAN CLUTCH (S52 / S54 / M52 / M52TU / M54 / M56) .
- Remove alternator drive belt, refer to 11 28 010 REPLACING ALTERNATOR DRIVE BELT (M52 / S52 / M52TU / M54 / M56) .
If necessary, drain supply tank for power steering pump, remove with holder and place to one side.
If fitted:
Remove air hose.
Version 1
Take off cap on connections.
Disconnect plug connection (1).
Release nut (2) and disconnect battery positive lead.
Tightening torque, refer to 12 31 1AZ in ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUES - 325I, CI & XI - E46 .
Version 2
Unlock and detach plug connection (1).
Release nut (2) and disconnect battery positive lead.
Tightening torque, refer to 12 31 1AZ in ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUES - 325I, CI & XI - E46 .
Version Without Idler Pulley:
Release alternator screws in succession while simultaneously gripping alternator firmly.
Remove alternator.
Version With Idler Pulley:
Remove cover from idler pulley (1).
Release screw and remove idler pulley (1).
Release screw and remove alternator (2).
Version With Idler Pulley:
Installation:
Turning lock of tensioning roller must engage in alternator groove.
Interrogate fault memory of DME control unit.
Now clear the fault memory.