DESCRIPTION
Depending on equipment, different output generators are installed on Z4.
Battery charging voltage varies according to ambient temperature. At lower temperatures, battery is less susceptible to boiling over and can be charged at higher voltages. At high temperature, charging voltage is reduced to prevent loss of battery electrolyte through evaporation. The Digital Motor Electronic (DME) control unit controls output rate of the generator.
GENERATOR & REGULATOR SWITCH
Check for correct connections on fully charged battery, generator and starter motor. Check for good ground connection between engine and body. Check for properly tightened drive belt. Connect DIS tester. Search down through the following menus
- FUNCTION SELECTION
- COMPLETE VEHICLE
- DRIVE
- VOLTAGE AND CURRENT REGULATION
- VOLTAGE AND CURRENT GENERATION
Work through test modules. To diagnose oscillograms for each fault, see
. If generator is faulty, repair or replace it. To replace, see
under REMOVAL & INSTALLATION.
| Fault | Oscillogram |
|---|---|
| Fault-Free | (Scheme 1) |
| One Phase Interrupted | (Scheme 2) |
| Internal Fault | (Scheme 3) |
| Open Circuit In Negative Diode | (Scheme 4) |
| Short Circuit In Positive Diode | (Scheme 5) |
| Open Circuit In Positive Diode | (Scheme 6) |
| Open Circuit In Exciter Diode | (Scheme 7) |
GENERATOR OSCILLOGRAMS
Scheme 1
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
CHECKING GENERATOR
Note. Generator with BSD interface can communicate with engine control unit (DME/DDE). Generator is not connected to charge telltale light. Generator can identify various faults.
Note. BSD generator can be recognized by plug connection on generator.
- Check for correct corrections on charged battery, generator and starter motor. Make sure of good ground connection between engine and body. Make sure of good tension on ribbed V-belt.
- Read out DME/DDE fault memory.
- Connect diagnosis tester. Search down the following menus: FUNCTION SELECTION COMPLETE VEHICLE DRIVE VOLTAGE AND CURRENT REGULATION VOLTAGE AND CURRENT GENERATION Follow instructions in diagnostic program. To diagnose oscillograms for each fault, see «GENERATOR OSCILLOGRAMS»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators) . If generator is faulty, repair or replace it. To replace, see «GENERATOR»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators) under REMOVAL & INSTALLATION.
REMOVAL & INSTALLATION
| CAUTION | Disconnecting vehicle battery will cancel fault codes of control units. On vehicles with radio codes, after disconnecting battery, radio codes must be re-entered. Obtain radio code card from customer. Note stored stations and restore them after connecting battery. Also, where applicable, initialize sunroof and set steering angle. |
A/C COMPRESSOR DRIVE BELT
Note. If drive belt is to be reused, mark direction of travel and reinstall drive belt in same direction.
- If necessary, remove splash guard. On models with hydraulic drive belt and tension jack, remove dust cap, push back belt tensioner at bolt connection of guide pulley and remove drive belt. (Scheme 8) On models with mechanical drive belt and tension jack, press back drive belt tensioner at hexagon head or Torx socket and remove drive belt. (Scheme 9)
- Check drive belt for coolant and oil residues. Replace if necessary. To install, reverse removal procedure. Make sure belt is correctly positioned on belt pulleys.
Scheme 8
Scheme 9
- Switch off ignition. Remove radiator cover. See «RADIATOR COVER»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators).
- Lift out expansion rivet (1). (Scheme 10) Remove screws (2). Unlock and detach plug connections (3). Remove fan cowl (4) towards top.
- To install, reverse removal procedure. Install original Automatic Recirculated Air Control (AUC) sensor to new fan cowl if replacing fan cowl.
Scheme 10
| CAUTION | Disconnecting vehicle battery will cancel fault codes of control units. On vehicles with radio codes, after disconnecting battery, radio codes must be re-entered. Obtain radio code card from customer. Note stored stations and restore them after connecting battery. Also, where applicable, initialize sunroof and set steering angle. |
Removal
- Retrieve fault codes. Turn off ignition. Disconnect and cover battery negative terminal.
- Remove intake filter housing. See «INTAKE FILTER HOUSING»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators). Remove generator drive belt. See «GENERATOR DRIVE BELT»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators__generator-drive-belt).
- Disconnect plug connection (1). (Scheme 11) Remove nut (2) and disconnect wire from battery positive lead.
- Remove cover from idler pulley (1). (Scheme 12) Remove screw and remove idler pulley (1). Remove screw and remove generator (2).
Scheme 11
Scheme 12
Installation
- To install, reverse removal procedure. Turning lock of tensioning roller must engage in generator groove. (Scheme 13)
- Tighten wire from battery positive lead to specification. See «TORQUE SPECIFICATIONS»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators__torque-specifications).
- Interrogate fault memory of DME control unit. Clear fault memory.
Scheme 13
- Remove generator drive belt. See «GENERATOR DRIVE BELT»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators__generator-drive-belt).
- Depending on generator type, grip shaft with one of the following: Hexagon Socket Multi-Tooth Socket Torx Socket Wrench Remove nut with Special Tool (12 7 110). (Scheme 14)
- To install, reverse removal procedure. Tighten nut to specification. See «TORQUE SPECIFICATIONS»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators__torque-specifications).
Scheme 14
GENERATOR DRIVE BELT
Note. If drive belt is to be reused, mark direction of travel and reinstall drive belt in same direction.
- Remove fan clutch with fan impeller.
- Remove A/C compressor drive belt. See «A/C COMPRESSOR DRIVE BELT»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators__ac-compressor-drive-belt).
- Remove radiator cover. See «RADIATOR COVER»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators).
- Remove fan cowl. See «FAN COWL»(/bmw/z4/e85e86-2002-2005/remont/charging-system/#generators-regulators).
- Remove cap from tensioning roller. (Scheme 15)
- Relieve tension on belt drive. (Scheme 16) Remove drive belt.
- Check drive belt for coolant and oil residues. Replace if necessary.
- To install, reverse removal procedure. Check that belt is correctly positioned on belt pulleys. (Scheme 17) Locking device of auxiliary tensioning roller must snap into groove on generator. (Scheme 18)
Scheme 15
Scheme 16
Scheme 17
Scheme 18
- Turn off ignition. Open clips (1) on top of intake filter. (Scheme 19) Open retainers (2) on air-mass flow sensor. Lift top section (3) of intake filter housing.
- Remove screws. (Scheme 20) Remove intake filter housing (1).
- To install, reverse removal procedure. Install guide rail (1) on intake filter housing on rubber mount (2). (Scheme 21)
Scheme 19
Scheme 20
Scheme 21
- Do not remove screws (1). (Scheme 22) They are bonded to cover. Release screws along line. Remove radiator cover (2).
- To install, reverse removal procedure.
Scheme 22
TORQUE SPECIFICATIONS
| Application | Ft. Lbs. (N.m) |
|---|---|
| Pulley | 33 (45) |
| Pulley (Ribbed Drive Belt) | 52 (70) |
| INCH Lbs. (N.m) | |
| Wires-To-Generator Nuts | 115 (13) |
TORQUE SPECIFICATIONS
