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121-11
Battery, Starter, ~lternatorl
Alternator 1997 - 98 5281 1997 540i
/-- -----,
I'
-----------
F15 / 7.5A/ :
&.. .... , 30 1 Xi0015
Battery
Hol in run 61 E (D+) Alternator
and stsrt
lBL
(Generator)
1 .--------,charge , . I , indicator I xGoli i
I <"9,7,a,T
Alternator, basic
On 1997-1 998 6-cylinderand 1997 V-8 models, the charging
system indicator light is supplied voltage
(+) to one side of the
light bulb, and the other side of the bulb is connected to the
voltage regulator.
With the engine off and the key in the run position, voltage
from the ignition switch flows through the regulator to ground,
completing the circuit and illuminating the charge indicator
bulb.
When the vehicle is started and the alternator begins to pro-
duce voltage, the output of the diode trio increases and the
light is turned off.
Alternator with multi-function control
(MFR)
Alternator with multi-function control
(MFR)
The multi-function controlled alternator is used on:
* 1999-2002 6-cylinder models
* 1998-2002 V-8 models
4 On cars with multi-function control alternator, the charge in-
dicator lamp is activated by means of an electronic switch in-
tegrated in the alternator controller. This switch receives its
voltage supply from terminal
15 on the 3-pin connector at the
rear of the alternator. The controller measures internally the
voltage difference between terminal 30 and terminal
15 and
signals the DME ECM to turn the charge indicator lamp on.
The controller features integrated fault detection. The battery
charge indicator lamp will come on in the event of:
* Failure of belt drive
No charge due to an
electrical/electronic fault
Interruption in excitation circuit
Over-voltage due to a defective controller output stage Fault or break in charge line
No charge due to alternator fault
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Battery, Starter, Alternator
Water-cooled alternator
The water-cooled alternator, used on 1999 and later M62 TU
engines, is a sealed unit housed inside the engine block wa-
ter jacket. It is cooled via the engine cooling system. It is a
"brushless" sealed unit that cannot be serviced. Maintaining
consistent alternator temperatures increases the life span of
the alternator, and elimination of the alternator cooling fan re-
duces alternator noise
significantly.
The M62 TU water-cooled alternator incorporates load start
reduction. This function is intended to shorten the duration of
engine starting, particularly at low ambienttemperatures. The
current load is limited to
20 amps during starting in order to re-
duce alternator braking torque on the engine. Following the
current limiting phase, full power output is then progressively
reached.
Charging system diagnostics requires special test equip-
ment. If the test equipment is not available, charging system
fault diagnosis can be performed by an authorized
BMW
dealer or other qualified repair shop. See Table a. Battery,
alternator and starter troubleshooting for general electri-
cal component troubleshooting.
Before checking the alternator, make sure the battery is fully
charged and capable of holding a charge. Check that the bat-
tery terminals are clean and tight and the alternator drive belt
is properly tensioned and not severely worn.
NOTE-
Some model require up to 15 second to reacli full alternator
output.
CA UTIOG
If the charge indicator light in the instrument cluster remains
on, the charge warning circuit in the instrument cluster may
be faulty. Check that the ground lead is securely
affached to
the grounding stud on the cylinder head
(A). Replacing the
instrument cluster before repairing the ground lead will both
damage the instrument cluster and cause the failure to
reoccur.
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Battery, Starter, ~lternatorl
Charging system quick-check
Use a digital multimeter to measure voltage across the bat-
tery terminals with key off and then again with engine running.
Battery voltage should be about 12.6 volts with key off and be-
tween 13.5 and 14.5 volts with engine running.
NOTE-
The regulated voltage (engine running) should be between
13.2 and 14.5, depending on temperature andoperating con-
ditions.
If the voltage is higher than 14.8, the voltage regula-
tor or
mulitfunction controller is most likely faulty
Check for clean and tight battery cables. Check ground cable
running from negative
(-) battery terminal to chassis and
ground cable running from engine to chassis. Check alterna-
tor drive belt condition and tension.
Charging system, checking
CAUTIOI\C
* Do not disconnect the battery while the engine is running.
Damage to the alternator and/or engine electronic systems
may result.
Only use a digital multimeter when testing charging
system components.
--7
4 Turn ignition key on. Check that battery warning light comes
on.
NOTE-
If the warning light does not come on, repair bulb or wiring
faults before continuing to checlc the charging system.
/ Charge indicator
502820805
4 6-cylinder engines only, remove complete air filter housing:
Loosen
intake duct hose clamp (A) at throttle assembly.
Loosen clamp and remove idle control hose from intake
duct
(B) and disconnect idle speed control valve electrical
harness connector.
Disconnect electrical harness connector
(C) from mass air
flow sensor.
Remove air filter housing mounting screw
(D).
Disconnect vent tube (E).
Loosen air intake duct clamp (F).
Carefully lift air filter housing out of engine bay.
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- -
/Battery, Starter, Alternator -- - -. - --I
< Check for battery voltage at alternator terminal 30 (B+) (ar-
row):
Pull back rubber insulating cover at terminal 30 at rear of
alternator.
Connect voltmeter between terminal 30 and ground and
check for battery voltage.
If voltage is not present, check
wiring for faults.
NOTE-
On V-8 engines, access to the rear of the alternator is limited.
Check for battery voltage between the jump start post on the
left cylinder head and ground.
r Disconnect harness connector from alternator. Turn ianition
on and check for battery voltage between terminal
lgand
ground. If voltage is not present, check wiring and fuses for
faults.
Reconnect connector to alternator.
Locate the blue wire coming from terminal
61E of the alter-
nator connector. Carefully connect the positive
(+) test lead
to the wire using a piercing test lead end.
Turn ignition key on and check for voltage. Voltage should be
less than 1.5 VDC and charge indicator lamp should light.
- Making sure all test equipment and tools are clear, start en-
gine. Voltage should increase to
8.0 VDC or higher. The
charge indicator light should go out.
If voltage does not increase and system is not charging,
the fault is in alternator.
- If voltage does not increase, but system is charging, inter- - roaate svstem for faults usina an appropriate BMW scan - .. . tool and'reset fault memory.
- If a load tester is not available, a quick alternator output test
can be done by running engine at about 2000 rpm and turn-
- -
ing on electrical loads (fans, lights, rear window defroster, -
- and wipers). With all accessories on, battery voltage should
be above 12.6
V.
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121-23
Battery, Starter, ~lternatorl
Solenoid switch, removing and installing
- Remove starter as described previously.
- Disconnect field winding strap between starter motor and
solenoid switch.
NOTE-
If the field winding strap is damaged or burned, a new or
rebuilt starter motor is needed.
< Remove solenoid switch mounting screws (arrows), and
separate solenoid from starter.
Unhoolc solenoid plunger from lever in starter drive
- Installation is reverse of removal. Lubricate solenoid piston
with light grease.
CAUTION- When installing field winding strap to starter, position
itso that
it does not contact the starter body.
Tightening torque
Field strap to starter
13 Nm (10 ff-lb)
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130-2
/Fuel Injection
This repair group covers service and repair of the Bosch and
Siemens engine management systems used on
1997
through 2002 E39 models. Additional engine management
service and repair information may also be found in the fol-
lowing repair groups:
0 020 Maintenance
120 Ignition System
160 Fuel Tank and Fuel Pump
610 Electrical Component Locations
OBD On Board Diagnostics
NOTE-
Camshaft position sensor, crankshaft speed sensor and
knoclc sensors are covered in 120 Ignition System.
Table a. Engine management system applications
- - ~ ~
1 ~odellmodel year / Engine IDME system I - I
5281, 1997-1 998 IM52. 2.8 liter ISiemens MS 41 .I I 1
528i. 1999ZO00 1~52 TU, 2.8 liter ]siemens MS 42.0 I I
5251, 2001-2002 1~54, 2.5 liter 1 Siemens MS 43.0 I I
530i, 2001-2002 1~54, 3.0 liter ISiemens MS 43.0
5401 1999-2001 1~62 TU, 4.4 liter l~osch ME 7.2
I
OBI) II software and hardware is incorporated in the engine
management control systems. The
OED II system monitors
components that influence exhaust and evaporative emis-
sions. If a problem is detected, the
OED I1 system stores the
associated fault code and condition.
540i. 1997
4 If vehicle emission levels exceed 1.5 times Federally mandat-
ed criteria, the
OED II system illuminates a malfunction indi-
cator light
(MIL) in the instrument cluster.
For the
E39 cars covered by this manual, three different
MIL symbols were used, depending on year and model.
See illustration.
When faults arise, or if the malfunction indicator lamp (MIL) is
illuminated, begin troubleshooting by connecting BMW ser-
vice tester
DISplus, MoDiC, GTl or equivalent scan tool. The
capabilities of OBD
II software has the potential to save hours
540i. 1998 IM62, 4.4 liter /Bosch M5.2.1
M62, 4.4 liter Bosch M5.2
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-
Fuel Injection
of diagnostic time and to help avoid incorrect component re-
placement and possible damage to system components.
NOTE-
* Professional diagnostic scan tools available at the time of
this printing include the BMW factory tools and a small
number of aftermarket BMW-specific tools. The
CS2000
from Baum Tools Unlimited, the Retriever from Assenma-
chef Specialty Tools, and the MT2500 from Snap-on are
three examples.
In addition to the BMW-specific professional line of scan
tools, there are inexpensive generic OBD
I1 scan tool soft-
ware programs and
handheld units available. Although
these tools have limited capabilities as compared to the
dedicated tools, they are powerful diagnostic tools.
For the
DIY owner, simple aftermarltet DTC readeris avail-
able through
http://www.pealteresearch.com. This tool is
capable of checlting for
DTCs as well as turning off the il-
luminated
MIL and resetting the service indicator lights.
Tools and test equipment
If the equipment required to do the job is unavailable, it is rec-
ommended that these repairs be left to an authorized
BMW
dealer or other qualified BMW repair facility.
4 Low current test light ("noid")
(Tool No. Baum 11 15a)
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Fuel Injection
Warnings and cautions
For personal safety, as well as the protection of sensitive
electronic components, adhere to the warnings and cautions
on the following pages.
WARNING-
Gasoline is highly flammable and its vapors are explosive.
Do not smoke or work on a car near heaters or other fire
hazards when diagnosing and repairing fuel system prob-
lems. Have a fire extinguisher available in case of an emer-
gency
Renew fuel system hoses, clamps and O-rings any
time they are removed.
When working on an open fuel system, wear suitable
hand protection, as prolonged contact
with fuel can
cause illnesses and skin disorders.
* The ignition system produces high voltages that can be
fatal. Avoid contact with exposed terminals. Use ex-
treme caution when
working on a car with the ignition
switched on or the engine running.
CAUTION-
- Disconnecting the battery may erase fault code($ storedin
memory Check for fault codes prior to disconnecting the
battery cables. Read the battery disconnection cautions in
001 General Warnings and Cautions.
a Connect and disconnect the DME system wiring and
1 test equipment leads only when the ignition is switched
off.
Wait at least 1 minute after turning off the ignition be-
fore removing the engine control module (ECM) con-
nector. If the connector is removed before this time,
residualpower in the system relay may damage the
control module.
Fuel system cleaners and other chemical additives oth-
er than those specifically recommended by BMW may
damage the catalytic converter, the oxygen sensor or
other fuel supply components.
* Do not connect any test equipment that delivers a 12-
volt power supply to terminal 15 (+) of the ignition coil.
The current flow may damage the ECM. In general,
connect test equipment only as specified by BMW or
the equipment maker.
Only use a digital
multirneter for electrical tests. Only
use an LED test light for
quiclc tests.