BMW 328i 1998 E36 Workshop Manual
Page 131 of 759
Camshaft
position
(CMP)
sensor,
replacing
(6-cylinder
engine)
1
.
Remove
plastic
cover
from
above
fuel
injectors
.
2
.
Disconnect
harness
connector
from
VANOS
solenoid
and
unscrew
solenoid
from
VANOS
control
unit
.
Re-
	
"
Clean
contactsurface
on
engine
block
before
fnstall
move
oil
supply
line
from
VANOS
control
unit
.
See
117
	
ing
knock
sensors
.
Camshaft
Timing
Chain
.
3
.
Remove
camshaft
position
(CMP)
sensor
from
left
frontof
cylinder
head,
next
to
top
of
oil
filter
housing
.
	
"
Knock
sensor
to
cylinder
block
....
20
Nm
(15
ft
.
lbs
.)
4
.
Disconnect
CMP
sensor
harnessfrom
under
intake
manifold
.
5
.
Installation
is
reverse
of
removal
.
Use
a
new
O-ring
when
installing
sensor
.
Be
sure
wiring
is
rerouted
in
same
orientation
.
Tightening
Torques
"
CMP
sensor
to
cylinder
head
....
.
.
..
5
Nm
(3
.5
ft-Ib)
"
VANOS
oil
supply
pipe
to
VANOS
control
unit
...........
.
..
32
Nm
(24
ft-Ib)
"
VANOS
solenoid
to
VANOS
control
unit
...
.
.................
30
Nm
(22
ft-Ib)
Knock
sensors,
replacing
Knock
sensors
are
usedon
engines
with
Bosch
DME
M1
.7,
Bosch
DME
M3
.3
.1,
Bosch
DME
M5
.2,
and
Siemens
MS
41
.1
engine
management
systems
.
The
knocksensors
are
bolted
to
the
left
sideof
the
cylinder
block
and
monitor
the
combus-
tion
chamber
for
engine-damaging
knock
.
If
engine
knock
is
detected,
the
ignition
point
is
retarded
accordingly
via
the
en-
gine
control
module
.
CA
UTION-
"
Label
knock
sensorharness
connectors
before
disconnecting
them
.
The
connectors
must
not
be
interchanged
.
Engine
damage
may
result
if
the
sensors
are
monitoring
the
wrong
cytinders
.
"
Note
the
installed
angle
of
the
knock
sensoron
the
block
before
removing
it
.
Reinstall
the
sensor
in
the
same
position
.
Be
sure
to
usea
torque
wrench
when
tightening
the
sensormounting
bola
NOTE
-
"
On
M52
engines,
a
single
harness
connects
the
twosensors
to
the
main
harness
connector
.
The
shorter
cable
lead
fs
for
the
knock
sensor
for
cytinders
4,
5,
and
6
.
Tightening
Torque
IGNITION
SYSTEM
	
120-
7
0012730
Fig
.
12
.
Knock
sensor
mounting
bolt
on
front
left
side
of
cylinder
block
.
NOTE-
Knock
sensor
function
Is
monitoredby
the
On-Board
Diagnostic
system
.
If
a
knock
sensor
is
detected
to
be
faulty,
an
appropriatediagnostic
trouble
code
(DTC)
may
be
stored
in
memory
.
See
100
Engine-General
for
information
on
retrieving
DTCs
.
On
6-cylinder
engines,
the
knock
sensors
are
accessible
af-
ter
removing
the
intake
manifold
.
On
4-cylinder
engines,
the
upper
section
of
the
intake
manifold
should
be
removed
to
ac-
cess
the
sensors
.
See
Fig
.
12
.
NOTE-
Intakemanifold
removal
and
installation
procedures
are
	
"
Cylinder
no
.
1is
at
the
front
of
the
engine
.
covered
in
113
Cylinder
HeadRemoval
and
Installation
.
Ignition
Firing
Order
Ignition
Firing
Order
"
4-cylinder
engines
.....
..
...
.
..........
.1-3-4-2
"
6-cylinder
engines
...........
..
.
.
..
..
1-5-3-6-2-4
IGNITION
SYSTEM
SCHEMATICS
Fig
.
13
through
Fig
.
17
show
ignition
system
schematics
usedon
the
enginescoveredby
this
manual
.
IGNITION
SYSTEM
SCHEMATICS 
Page 132 of 759
120-8
	
IGNITION
SYSTEM
1
	
1
.0
GN
	
1
.0
Gl
.0
GN
I
	
Ign
coil
	
1
.0
GN
.
Tti
	
%ti
	
r,
	
_%ti
_
	
_
ice_
I
	
25
	
52
5524
	
51
	
54
	
56
I
	
Power
input
	
power
input
t
	
U
	
Engine
Control
Module
(Bosch
DME
Ml
.7)
	
II
	
Powerinput
Mainrelaycontrol
I
15
42
	
43
	
16442868
67
	
34
6
26
	
27
1
-----
	
__
V
	
_
	
--
	
_
~
8K
	
.35
BK
.35
13,1
1
	
.35
YE
	
1
	
.35
BK35
VE
.35
3
	
cyl
.1
1
11
E
S
2
1
.0
BR
2
.5
BR
Ign
.
coil
cyl
.
3
	
II
Ign
.
coil
	
Ign
.
coil
3
	
cyI
.
2
	
1
Y
_
Y
2
	
k
3
	
cyl
.
4
IGNITION
SYSTEM
SCHEMATICS
Battery
voltage
in
run
or
start
(
vía
ignition
switchterminal
15)
	
WIRING
COLOR
CODE
4
.0
GN
1
.0
BR'V
.
Camshaft
Knock
Sensor
Knock
Sensor
	
Position
(cyl
.1-2)
(cyl
.3-4)
	
Sensor
Fig
.
13
.
Bosch
DME
M1
.7
ignition
system
circuit
for
M42
engine
.
Ground
(RH
rearof
engine
compartment,
rear
of
shock
tower)
N[INS
Crankshaftlrpm
Position
Sensor
Battery
voltage
in
run
or
start
(vía
main
relay
terminal
87)
Ground
(RH
rearof
engine
compartment,
rearof
shock
tower)
5GN
BK
-
BLACK
BR
"
BROWN
RD
-
RED
YL-
YELLOW
GN
-
GREEN
BL
-
BLUE
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
Warning
:
Lethal
voltagepresent
Battery
voltage
at
all
times
to
Main
relay
(terminal
85)
'Y
Y
---------------------
0013087 
Page 133 of 759
^1
.5WT
^1
.5RD
^1
.5YL
^1
.5BL
r
	
--__
	
____-
	
__-_
	
___-_
	
-___-_____--__--
	
-____-___
	
____-
i
26
g
5022
23
	
54
	
5
I
	
Power
input
	
power
input
I
	
Engine
Control
Module
(Bosch
DME
M5
.2)
	
I
I
	
grounds
	
I
P
owerinput
	
Main
relay
control
	
I
70
40
	
71
	
21
	
2078
	
34
55
626
	
27
----------------------
-
---------
-
--
-
------------
-
-----------
.,
	
v
1
1
.1
	
v
`
1
35BK
	
35BK
2
(
	
1Y
	
¡3
	
194
Knock
Sensor
Knock
Sensor
(cyl
.1-2)
(cyl
.3-4)
Frommain
relay
terminal
87
(battery
voltage
in
run
or
start
Battery
voltage
in
run
or
start
(
via
ignition
switch
	
Warnin
terminal
15)
	
Lethal
óltage
	
WIRING
present
	
COLOR
CODE
2
.5
GN
	
'
1
.0
YL
	
/
1
.0
BL
	
/
1
.0
RDNJT
.35
BK
/
	
/
.35
BK
Camshaft
Position
Sensor
-_
Fig
.
14
.
Bosch
DME
M5
.2
ignition
system
circuit
for
M44
engine
.
Ground
(RH
rear
of
engine
compartment,
rearof
shock
tower)
Crankshaftirpm
Position
Sensor
IGNITION
SYSTEM
	
120-9
Batteryvoltage
	
Battery
voltage
in
run
or
start
	
in
run
or
start
(via
main
relay
	
(
via
ignition
switch
terminal
87)
	
terminal
15)
BK
-
BLACX
BR
-
BROWN
RD
-
RED
YL
-
YELLOW
GN
-
GREEN
BL
-
BLUE
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
Battery
voltage
at
all
times
to
Main
relay
(terminal
85)
Ground
(RH
rear
of
engine
compartment,
rearof
shock
tower)
	
0012721
lGNITION
SYSTEM
SCHEMATlCS 
Page 134 of 759
120-10
	
IGNITION
SYSTEM
Ground
(rear
of
engine
compartment,
rear
of
passenger
side
shock
tower)
.!
BK
Camshaft
Position
Sensor
IGNITION
SYSTEM
SCHEMATICS
Batteryvoltage
in
run
or
start
(
via
ignition
switch
terminal
15)
---------------------------------------------------------
55
	
S5154
i
power
input
	
Power
input
	
1
DME
Control
Module(Bosch
DME
M3
.1)
Ground
-
(RHrear
of
enginecompartment,
rearof
passenger
side
shock
tower)
Fig
.
15
.
Bosch
DME
M3
.1
usedon1992
M50
engines(without
VANOS)
.
.EBK
Crankshaftlrpm
Position
Sensor
5GN
1.0
RD
Ground
(RH
rearof
enginecompartment,
rear
of
passenger
side
shock
tower)
WIRING
COLOR
CODE
BK
-
BLACK
BR
-
BROWN
RD
-
RED
YL
-
YELLOWGN
-
GREEN
BL
-
BLUE
VI-
VIOLET
GY
"
GREY
WT
"
WHITE
PK
-
PINK
Batteryvoltage
in
run
or
start
(
via
main
relay
Battery
voltage
	
terminal
87)
in
run
or
start
(via
ignition
switch
terminal
15)
11508
1
grounds
	
Main
rela
control
P
ower
Input
	
Y
	
I
-
34
---"--
6
26
27
1
Battery
voltage
at
all
times
to
Main
relay
(terminal
85) 
Page 135 of 759
RER
Knock
Sensor
Knock
Sensor
(cyl
.1-3)
(cyl
.4-6)
Batteryvoltage
	
IMIRING
in
run
or
start
	
COLORCODE
(
via
ignition
switch
termina¡
15)
	
BK
	
BLAOK
BR
BROWN
RD
-
RED
YL
-
YELLOW
GN
"
GREEN
EL
-
BLUF
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
4
.0
GN
l1/1j\
I'1
/~/1r1
	
l\r1
1
55
	
so
	
si
	
52
	
23
	
25
	
24
	
56
	
54
1
Power
input
	
Power
input
	
III
	
O
Engine
Control
Module
(Bosch
DMEM13
.1)
	
II
	
grounds
	
P
ower
input
	
Main
relaY
control
I
70
__
_
71
	
69
	
17
	
28
	
43
	
16
	
-34---"-6
	
26
	
27
____________________________________________
From
main
relaterminal
87
(battery
voltage
in
run
or
start
.5
YL
Camshaft
Position
Sensor
Ground
(RH
rearof
enginecompartment,
rear
of
shock
tower)
.5
BK
Crankshaft/rpm
Position
Sensor
Fig
.
16
.
Bosch
DME
M33
.1
ignition
system
círcuit
for
1993-1995
M50
engines
with
VANOS
.
IGNITION
SYSTEM
	
120-11
Ground
=
(RH
rear
of
engine
compartment,
back
sideof
shock
tower)
Batteryvoltage
	
Battery
voltage
in
run
or
start
	
in
run
or
start
(
via
ignition
switch
	
(
via
main
relay
terminal
15)
	
terminal
87)
1
.0
RD
11506a
.5
BR
Batteryvoltage
at
all
times
to
Main
relay
(terminal
85)
IGNITION
SYSTEM
SCHEMATICS 
Page 136 of 759
120-12
	
IGNITION
SYSTEM
Warning
.
Lethal
voltagepresent
Battery
voltage
in
run
or
start
(via
ignitíon
switch
terminal
15)
I
t
IGNITION
SYSTEM
SCHEMATICS
Battery
voltage
in
run
or
start
(
via
ignition
switchterminal
15)
	
WIRING
COLOR
CODE
Knock
Sensor
Knock
Sensor
	
Crankshaftlrpm
	
Camshaft
(cyl
.
1-3)
	
(cyl
.
4-6)
	
Position
Sensor
	
Position
-
-
Sensor
-
Fig
.
17
.
Siemens
MS
41
.1
ignition
systemusedon1996
and
later
6-cylinder
engines
.
1.0
BR
PQ
1
.08~1
.0BKIRD
	
/1
.0BK/YL
	
'10BK/BL
	
'1
.03KIGN
	
10BKNI
4
1D
BK
-
BLACK
BR
-
BROWN
RD
-
RED
YL
-
YELLOW
GN
-
GREEN
BL
-
BLUE
VI-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK
Batteryvoltage
in
run
or
start
(via
main
relay
terminal
87)
!1
	
rl
1.0
B~
	
^
1.0
BK/RD
	
^
1.0
BKIYL
	
^
1
.0
BK/BL
	
n
1.0
BK/GN
	
n
1
.0
BKIVI
	
%~
r
-------
--------------_____________----_______-_-____
49
	
29
	
1
	
30
	
2
	
31
	
3
	
8754
1
power
input
	
Power
input
	
I
1
	
Engine
Control
Module
(Siemens
MS
41
.1)
	
1
1
	
grounds
	
1
n
1
	
Powerinput
Mainrelaycontrol
1
1-
57
___
58
	
_
59
_
__
63
_
	
38
	
83
	
48
	
40
	
64
	
43
	
65
	
41
	
28
	
32
	
34
	
4
	
26
	
73
	
1
-
	
-----------
-
_-----
-
------
_
------
-
------
-
---
	
-
.5Y1-
	
.5BKY.5GNY.5BRY
Y
	
.35BKY
1
Y
	
Y
	
.35BKY/Y35YY
75
.18R/
.5YL-1
1'
.
Batteryvoltage
at
all
times
to
Main
relay
(terminal
85)
Ground
	
v
(RH
rear
of
engine
	
Z
compartment,
rear
	
=
of
shock
tower)
	
Ground
(RH
rear
of
enginecompartment,
rearof
shock
tower)
	
0012731 
Page 137 of 759
CHARGING
SYSTEM
TROUBLESHOOTING
.............
.
.
.
.
.121-2
Charging
System
Quick-Check
...
.
..
.
...
.
121-2
Static
current
draw,
checking
........
.
...
.
121-2
BATTERY
SERVICE
....................
121-3
Battery
Testing
.
.
.
.
.
.........
.
........
.
121-3
Hydrometer
Testing
.
...
.
.
.
...
.
.........
121-3
Battery
Open-Circuit
Voltage
Test
....
.
....
121-4
Battery
Load
Voltage
Test
.
.
.
.
.
.
.........
121-4
Battery
Charging
.
.
.
.
...
.
.
.
.
.
.
.
.........
121-4
ALTERNATOR
SERVICE
.
.
.
.
.
.
.....
.
...
121-4
Chargingsystem,checking
.
.
.
.
.
.........
121-4
Alternator,
removingand
installing
(4-cylinder
engine)
....
.
.
.
.
.
.
.
.........
121-5
Alternator,
removingand
installing
(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.........
121-6
GENERAL
The
charging
system
consists
of
a
belt-driven
alternator
with
integral
voltage
regulator
and
a
battery
mounted
in
the
luggage
compartment
.
Various
versions
of
alternators,
voltage
regulators,
starters,
and
batteries
are
used
in
the
E36
cars
.
It
is
important
to
re-
place
components
according
tothe
original
equipment
speci-
fication
.
Check
with
an
authorized
BMW
dealer
for
specific
application
and
parts
information
.
WARNING
-
"
Weargoggles,
rubbergloves,
and
a
rubberapron
when
working
around
batteries
and
battery
acid
(electrolyte)
.
"
Battery
acid
contains
sulfuric
acid
and
can
cause
skin
irritation
and
burning
.
ff
acid
is
spilled
onyour
skin
or
clothing,
flush
the
area
at
once
with
large
quantities
of
water
.
lf
electrolyte
gets
into
your
eyes,flush
them
with
largequantities
of
clean
wa-
terfor
several
minutes
and
call
a
physician
.
"
Batteries
that
are
being
charged
or
are
fully
charged
give
off
explosive
hydrogen
gas
.
Keep
sparks
and
open
flames
away
.
Do
not
smoke
.
BATTERY,
STARTER,
ALTERNATOR
	
121-1
121
Battery,
Starter,
Alternator
GENERAL
..
.
...
.
........
.
...
.
.
.
.
.
.
.
.
.
121-1
	
Voltage
regulator,
removing
and
ínstalling
.
.
.
121-6
Alternator
brushes,
inspecting
and
replacing
.121-7
STARTER
SERVICE
....
.
.
.
.
.
..........
.121-7
Starter
Troubleshootíng
	
121-7
	
15
..
.
.
.
.
.
........
.
.
.
Starter,
removing
and
installing
(4-cylinder
engine)
....
.
.
.
............
.
121-8
Starter,
removing
and
installing
(6-cylinder
engine
with
manual
transmission)
..
.
...........
.
...
121-8
Starter,
removing
and
installing
(6-cylinder
engine
with
automatic
transmission)
................
121-9
Solenoid
switch,
removingand
installing
....
121-10
TABLES
a
.
Battery,
Starter
and
Charging
System
Troubleshooting
............
.
.
.
.
:...
........
121-2
b
.
Specific
Gravity
of
Battery
Electrolyte
at
80°F
(27°C)
...............
.
.
..
..........
121-3
c
.
Open-Circuit
Voltage
and
Battery
Charge
........
121-4
d
.
Battery
Load
Test-Minimum
Voltage
.
..........
121-4
CAUTION
-
"
Prior
to
disconnectiog
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
"
Disconnecting
the
battery
cables
may
erase
fault
codes
stored
in
control
unit
memory
.
"
Always
disconnect
the
negative
()
battery
cable
first
and
reconnect
it
last
.
Cover
the
battery
post
with
an
insulating
material
whenever
the
cable
is
removed
.
"
After
reconnecting
the
battery,
the
power
window
motors
must
be
reinitialized
.
See
511
Door
Win-
dows
.
"
Never
reverse
the
battery
cables
.
Even
a
momen-
tary
wrong
connection
can
damage
the
alternatoror
other
electrical
components
.
"
Battery
cables
may
be
the
same
color
.
Label
ca-blebefore
removing
.
GENERAL 
Page 138 of 759
121-2
	
BATTERY,
STARTER,
ALTERNATOR
CHARGING
SYSTEM
TROUBLESHOOTING
	
Static
currentdraw,
checking
Charging
system
diagnostics
requires
special
test
equip-
ment
.
If
the
test
equipment
is
not
available,
charging
system
fault
diagnosis
can
be
performedby
an
authorized
BMW
deal-
eror
other
qualified
repair
shop
.
A
general
troubleshooting
guide
is
given
in
Table
a
.
Charging
System
Quick-Check
As
a
quick-check,
use
a
digital
multimeter
lo
measure
volt-
	
2
.
Disconnect
battery
negative
(-)
cable
.
age
across
the
battery
terminals
with
the
key
off
and
then
again
with
the
engine
running
.
The
battery
voltage
should
be
	
CAUTION-
about12
.6
volts
with
key
off
and
approximately
14
.0
volts
with
	
Prior
to
disconnecting
the
battery,
read
the
battery
the
engine
running
.
If
the
voltage
does
not
increase
when
the
	
disconnection
cautions
given
at
the
front
of
this
engine
is
running,there
is
a
fault
in
the
charging
system
.
	
manual
onpaga
viii
.
NOTE
-
The
regulated
voltage
(engine
running)
should
be
be-
tween
13
.5
and
14
.5,
depending
on
temperatura
and
operating
conditions
.
If
the
voltage
is
higher
than
14
.8,
the
voltage
regulator
is
most
Mely
faulty
.
Check
for
clean
and
tight
battery
cables
.
Check
the
ground
cable
running
from
the
negative
(-)
battery
terminal
lo
the
chassis
and
the
ground
cable
running
from
the
engine
lo
the
chassis
.
Check
the
alternator
drive
belt
condition
and
tension
.
If
the
battery
discharges
over
time,
there
may
be
a
constant
drain
or
current
draw
on
the
battery
.
A
small
static
drain
on
the
battery
is
normal,
but
a
largedrain
will
cause
the
battery
lo
quickly
discharge
.
Make
a
static
current
draw
test
asthe
first
step
when
experiencing
battery
discharge
.
1
.
Make
sure
ignition
and
al¡
electrical
accessories
are
switched
off
.
3
.
Connect
a
digital
ammeter
between
negative
battery
post
and
negative
battery
cable
lo
measure
current
.
See
Fig
.
1
.
Wait
at
least
one
minuta
lo
get
an
accurate
reading
.
A
range
of
about
0
lo
100
milliamps
is
normal,
dependingon
the
number
of
accessories
that
need
constant
power
.
A
current
of
400
milliamps
(0.4
amp)
or
more
may
indicate
a
problem
.
Table
a
.
Battery,
Starter
and
Charging
System
Troubleshooting
Symptom
	
1
	
Probable
Cause
	
1
	
Correctiva
Action
1
.
Engine
cranks
slowlyor
not
	
a
.
Battery
cables
loose,
dirty
orcor-
	
a
.
Clean
or
replace
cables
.
See020
Maintenance
Program
.
a
tall,
solenoíd
clicks
when
	
roded
.
starter
is
operated
.
	
b
.
Battery
discharged
.
	
b
.
Charge
battery,
test
and
replace
if
necessary
.
c
.
Body
ground
straploose,
dirty
or
	
c
.
Inspect
ground
strap,
clean,
tighten
or
replace
if
necessary
.
corroded
.
d
.
Poor
connection
at
starter
motor
	
d
.
Check
connections,
test
for
voltage
at
starter
.
Test
for
voltage
at
terminal
30
.
	
neutral
safety
or
clutch
interlock
switch
.
e
.
Starter
motor
or
solenoid
faulty
.
	
e
.
Test
starter
.
2
.
Battery
will
not
stay
	
a
.
Short
circuit
draining
the
battery
.
	
a
.
Test
for
excessive
current
drainwith
everything
electrical
in
the
charged
more
than
a
few
	
vehicle
off
.
days
.
	
b
.
Short
driving
trips
and
high
elec-
	
b
.
Evaluate
driving
style
.
Where
possible,
reduce
electrical
con
trical
drain
on
charging
system
	
sumption
when
making
short
trips
.
does
not
allow
battery
to
re-
charge
.
c
.
Drive
belt(s)
worn
or
damaged
.
	
c
.
Inspect
or
replace
multi-ribbed
belt(s)
.
See
020
Maintenance
Program
.
d
.
Battery
faulty
.
	
d
.
Test
battery
and
replace
íf
necessary
.
e
.
Battery
cables
loose,
dirty
orcor-
	
e
.
Clean
or
replace
cables
.
See
020
Maintenance
Program
.
rodad
.
f
.
Alternatoror
voltage
regulator
	
f
.
Test
alternator
and
voltage
regulator
.
faulty
.
3
.
Battery
losing
water
.
	
1
a
.
Battery
overcharging
.
	
1
a
.
Test
voltage
regulator
for
proper
operation
.
4
.
Lights
dim,
light
intensity
	
a
.
Drive
belt(s)
worn
or
damaged
.
	
a
.
Inspect
or
replace
multi-ribbed
belt(s)
.
See
020
Maintenance
varies
with
engine
speed
.
	
Program
.
b
.
Alternatoror
voltage
regulator
	
b
.
Test
alternator
and
voltage
regulator
.
faulty
.
c
.
Body
ground
straps
loose,
dirty
or
	
c
.
Inspect
ground
straps,
clean,
tighten
or
replace
as
necessary
.
corroded
.
CHARGING
SYSTEM
TROUBLESHOOTING 
Page 139 of 759
Fig
.1.
	
Electrical
system
static
current
draw
being
measured
.
To
determine
the
circuit
or
component
causing
the
problem,
remove
one
Puse
at
a
time
until
the
current
drops
to
a
normal
range
.
BATTERY
SERVICE
The
E36
uses
a
six-cell,
12-volt
leadacid
battery
mounted
in
the
luggage
compartment
.
See
Fig
.
2
.
NOTE-
E36
convertible
models
require
a
specialbattery
which
is
designed
for
constant
vibratfon
.
A
battery
not
de-signed
for
this
will
fail
much
earlier
.
Battery
capacity
is
determined
by
the
amount
of
current
needed
tostart
the
vehicle,
and
by
the
amount
of
current
con-
sumed
by
the
electrical
system
.
BMW
batteries
are
rated
by
ampere/hours
(Ah)
and
cold
cranking
amps
(CCA)
rating
.
The
Ah
rating
is
determined
by
the
average
amount
of
current
the
battery
can
deliver
over
time
without
dropping
below
a
specified
voltage
.
The
CCA
is
determined
by
the
battery's
ability
to
deliver
starting
current
at
0°
F
(-18°
C)
without
dropping
below
a
specified
voltage
.
Battery
Testing
noN~A
B9517
Battery
testing
determines
the
state
of
battery
charge
.
On
conventional
or
low-maintenance
batteries
the
most
common
method
of
testing
the
battery
is
that
of
checking
the
specific
gravity
of
the
electrolyte
using
a
hydrometer
.
Before
testing
the
battery,
check
that
the
cables
are
tight
and
free
of
corro-
sion
.
See
Fig
.
2
.
Hydrometer
Testing
The
hydrometer
consists
of
a
glass
cylinder
with
a
freely
moving
float
inside
.
When
electrolyte
is
drawn
into
the
cylin-
der,
the
levelto
which
the
float
sinks
indicates
the
specific
BATTERY,
STARTER,
ALTERNATOR
	
121-
3
Fig
.
2
.
	
Battery
in
right
sideof
luggage
compartment
.
gravity
of
the
electrolyte
.
The
more
dense
the
concentration
of
sulfuric
acid
in
the
electrolyte,
the
less
the
float
will
sink,
result-
ing
in
a
higher
reading
and
indicating
a
higher
state
of
charge)
.
NOTE-
Electrolyte
temperature
affects
hydrometer
reading
.
Check
the
electrolyte
temperaturewith
a
thermometer
.
Add
0
.004
to
the
hydrometer
reading
for
every
10°F
(6°C)
that
the
electrolyte
is
above
80°F
(27°C)
.
Sub-
tract
0
.004
from
the
reading
for
every
10°F
(6°C)
that
the
electrolyte
is
below
80°F
(27°C)
.
Before
checking
the
specificgravity
of
a
battery,
load
the
battery
with
15
amperes
for
one
minute
.
lf
the
battery
is
in-
stalled
in
the
vehicle,
this
can
be
done
by
turning
on
the
head-
lights
without
the
engine
running
.
Table
b
lists
the
percentage
of
charge
based
on
specific
gravity
values
.
Table
b
.
Specific
Gravity
of
Battery
Electrolyteat
80
°
F
(27°C)
Specific
gravity
	
1
	
Stateof
charge
1
.265
	
Fully
charged
1
.225
	
75%
charged
1
.190
	
50%
charged
1
.155
	
25%
charged
1
.120
	
Fully
discharged
The
battery
isin
satisfactory
condition
if
theaverage
specif-
ic
gravity
of
the
six
cells
is
at
least
1
.225
.
If
the
specific
gravity
is
above
this
leve¡,
butthe
battery
lacks
power
for
starting,
de-
termine
the
battery's
senrice
condition
with
a
load
voltage
test,
as
described
below
.
If
the
average
specific
gravity
of
the
six
cells
is
below
1
.225,
remove
the
battery
from
the
luggage
compartment
and
recharge
.
If,
after
recharging,
the
specific
gravity
varies
by
more
than
0
.005
between
any
two
celis,
re-
place
the
battery
.
CHARGING
SYSTEM
TROUBLESHOOTING 
Page 140 of 759
121-
4
	
BATTERY,
STARTER,
ALTERNATOR
BatteryOpen-Circuit
Voltage
Test
	
Battery
Charging
Before
making
the
test,
load
the
battery
with
15
amperes
for
	
Discharged
batteries
can
be
recharged
using
a
battery
one
minute
with
a
batteryload-tester
or
turn
on
the
headlights
	
charger
.
The
battery
should
be
removed
from
the
luggage
for
about
one
minute
without
the
engine
running
.Then
discon-
	
compartment
during
charging
.
nect
the
battery
negative
(-)
cable
and
connect
a
digital
volt-
meter
acrossthe
battery
terminals
.
Open-circuit
voltage
	
Prolonged
charging
causes
electrolyte
evaporation
to
a
lev
levels
are
given
in
Table
c
.
	
el
that
can
damage
the
battery
.
Itis
bestto
use
a
low-current
charger
(6
amperes
or
less)
to
prevent
battery
damage
If
the
open-circuit
voltage
ís
OK
butthe
battery
still
lacks
	
caused
by
overheating
.
power
for
starting,
make
a
load
voltage
test
.
If
the
open-circuit
voltage
is
below
12
.4
volts,
recharge
the
battery
and
retest
.
	
WARNING
-
Hydrogen
gas
given
off
by
the
battery
duringcharg-
Table
c
.
Open-Circuit
Voltage
and
Battery
Charge
	
ing
is
explosive
.
Do
not
smoke
.
Keep
open
llames
away
from
the
top
of
the
battery,
and
prevent
elec
Open-circuit
voltage
	
State
of
charge
	
trical
sparks
by
turning
offthe
battery
charger
be-
12
.6
V
or
more
	
Fully
charged
	
fore
connecting
or
disconnecting
it
.
12
.4
V
	
1
	
75%
charged
12
.2
V
	
50%
charged
	
CAUTION-
12
.0
V
	
25%
charged
	
"
Battery
electrolyte
(sulfuric
acid)
can
damage
the
car
.
If
electrolyte
isspilled,
clean
the
area
11
.7
V
or
less
	
Fully
discharged
	
with
a
solution
of
baking
soda
and
water
.
Battery
Load
Voltage
Test
A
battery
load
tester
is
required
for
a
load
voltage
test
.
The
	
-
Always
disconnect
both
battery
cables
and
re-
test
is
made
by
applying
a
high
resistive
load
to
the
battery
ter-
	
move
battery
from
vehicle
during
battery
charg-
ing
.
Do
not
exceed
16
.5volts
at
the
battery
.
minals
and
then
measuring
battery
voltage
.
The
battery
should
be
fully
charged
for
the
most
accurate
results
.
The
battery
ca-
bles
mustbe
disconnected
before
making
the
test
.
If
the
volt-
	
ALTERNATOR
$ERVICE
age
is
below
that
listed
in
Table
d,
the
battery
should
be
replaced
.
WARNING
-
Always
wear
protective
goggles
and
clothing
when
performing
aload
test
.
Table
d
.
Battery
Load
Test-Minimum
Voltage
(apply
200
amp
load
for
15
seconds)
Ambient
temperature
	
Voltage
80°F
(27°C)
	
9
.6
V
60°F
(16°C)
	
9
.5
V
40°F
(4°C)
	
9
.3
V
20°F
(-7°C)
	
8
.9
V
0°F
(-18°C)
	
8
.5
V
ALTERNATOR
SERVICE
"
Always
allow
a
frozen
battery
to
thaw
before
at-
tempting
to
recharge
it
.
Before
checking
the
alternator
and
regulator,
make
sure
the
battery
is
fully
charged
and
capable
of
holding
acharge
.
Check
that
the
battery
terminals
are
clean
and
tight
and
the
al-
ternator
drive
belt
is
properly
tensioned
and
not
severely
worn
.
Charging
system,
checking
CAUTION-
Do
not
disconnect
the
battery
while
the
engine
is
running,
.
Damage
to
the
alternator
andlorengine
electronic
systems
may
result
.
1.
Turn
ignition
key
on
.
Check
that
the
chargewarning
lamp
comes
on
.
NOTE-
If
the
warning
light
does
not
come
on,
repair
any
wiring
or
bulb
faults
before
continuing
to
check
the
charging
system
.