battery BMW 318i 1996 E36 Service Manual
[x] Cancel search | Manufacturer: BMW, Model Year: 1996, Model line: 318i, Model: BMW 318i 1996 E36Pages: 759
Page 127 of 759
IGNITION
SYSTEM
DIAGNOSTICS
IGNITION
SYSTEM
SERVICE
Poor
driveability
may
have
a
variety
of
causes
.
The
fault
On
4-cylinder
engines,
an
ignition
coil
pack
is
mounted
to
may
lie
with
the
ignition
system,
the
fuel
system,
parts
of
the
the
passenger
side
strut
tower
in
the
engine
compartment
.
emission
control
system,
or
a
combination
of
the
three
.
Be-
The
coil
pack
integrates
4
individual
coils
.
cause
of
these
interrelated
functions
and
their
effects
oneach
other,
it
is
often
difficult
to
know
where
to
begin
looking
for
On
6-cylinder
engines,
an
ignition
coil
is
located
directly
problems
.
above
each
spark
plug
.
For
this
reason,
effective
troubleshooting
should
alwaysbe-
gin
with
an
interrogation
of
the
On-Board
Diagnostic
(OBD)
system
.
The
OBD
system
detects
certain
emissions-related
engine
management
malfunctions
.
When
faults
are
detected,
the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in
the
system
ECM
.
In
addition,
the
Check
Enginewarning
light
will
come
on
if
an
emissions-related
fault
is
detected
.
Two
generations
of
OBD
areusedon
the
cars
coveredby
this
manual
.
See
100
Engine-General
for
OBD
information
.
On-Board
Diagnostics
"
1992-1995
models
............
...
.
..
...
OBD
I
"
1996
and
later
models
.........
.......
..
OBD
II
NOTE-
"
On
carswith
OBD
ti,
specialized
OBD
11
scan
tool
equipment
mustbeused
to
access
DTCs,
either
using
the
BMW
special
tool
or
a
`generic"
OBD
11
scan
tool
.
"
The
OBD
11
fault
memory
(including
an
illuminated
Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
from
the
ECM
or
dísconnecting
the
battery
will
not
erase
the
fault
memory
.
Basic
Troubleshooting
Principies
An
engine
that
starts
and
runs
indicates
the
ignition
system
is
fundamentally
working-delivering
voltage
toat
least
some
of
the
sparkplugs
.
A
hard-starting
or
poor-running
engine,
however,
may
indicate
ignition
coil
problems,
cracked
or
dete-
riorated
spark
plug
wires
(4-cylinder
engines
only),
and
worn
or
fouled
spark
plugs
.
WARNING
-
Inefficient
combustion
(richair/fuel
mixture)
can
cause
the
catalytic
converter
to
overheat
and
plug
.
An
overheated
catalytic
converter
can
also
bea
tire
hazard
.
Checking
for
Spark
IGNITION
SYSTEM
120-
3
WARNING
-
If
a
spark
test
is
done
incorrectly,
damage
to
theen-
gine
control
module
(ECM)
or
the
ignitioncoil(s)
may
result
.
Checking
for
spark
is
difficult
onengines
with
distributorless
ignition
systems
.
Try
Rmovng
the
plugs
and
inspecting
for
differences
be-
tween
them
.
A
poor-firing
plug
may
be
wet
with
fuel
and/or
black
and
sooty,
butnot
always
.
If
a
coil
is
not
operating,
the
engine
management
system
will
electrically
disable
the
fuel
injectorto
that
cylinder
.
The
key
is
to
look
for
differences
be-
tween
cylinders
.
Ignition
coil,
testing
and
replacing
(4-cylinder
engine)
1.
Disconnect
mainharness
connector
from
coils
:
"
On
M42
engine,
remove
plastic
covering
from
coils
and
disconnect
individual
harness
connectors
.
"
On
M44
engine,
disconnect
main
harness
connectorat
end
of
coil
pack
.
See
Fig
.
3
.
Fig
.
3
.
Ignition
coil
pack
for
M44
engine
(arrow)
.
Coil
harness
con-
nector
shown
at1
.
IGNITION
SYSTEM
SERVICE
Page 128 of 759
120-
4
IGNITION
SYSTEM
2
.
Check
for
battery
voltage
o
cofs
.
If
voltage
is
not
Table
b
.
Ignition
Coil
Resistance
present,
check
wire
between
terminal
15
and
ignition
(M42
Engine)
switch
.
See
Electrical
Wiring
Diagrams
.
"
On
M42
engine,
connect
digital
multimeter
between
ter-
minal
15(+)
in
each
harness
connector
and
ground
.
See
Fig
.
4
.
"
On
M44
engine,
connect
voltmeter
between
terminal
2
(15+)
in
connector
and
ground
.
Turn
ignition
on
and
check
for
voltage
.
See
Fig
.
5
.
3
.
Turn
ignition
off
.
0
4a15
Fig
.
4
.
Ignition
coil
harness
connector
terminal
identification
for
M42
engine
.
Fig
.
5
.
Ignition
coil
harness
connector
terminal
identification
for
M44
engine
.
CAUTION-
The
wiring
to
the
coil(via
the
ignition
switch
15+)
is
not
fuse
protected
.
Use
care
when
testing
thiscircuit
.
4
.
Use
a
digital
multimeter
totest
coil
primary
resistance
.
"
On
M42
engine,
use
Table
b
asa
guide
to
check
coil
resistance
.
Make
checks
at
each
harness
connector
.
"
On
M44
engine,
use
Table,c
as
a
guide
to
check
coil
primary
resistance
.
5
.
Inspect
coil
housing
for
hairline
cracks
or
leaking
cast-
ing
material
.
See
Fig
.
7
.
A
leaky
ignition
coil
may
indi-
11502
cate
a
faulty
ECM
(engine
control
module)
.
Check
the
ECM
before
installing
a
new
coil
.
Fig
.
6
.
Ignition
coil
harnessconnector
terminal
identification
for
6-
cylinder
engine
.
IGNITION
SYSTEM
SERVICE
11502
Terminals
Resistance
(refer
to
Fig
.
4
.)
Coil
primary
1
(-)
and
15
(+)
10
.4-0
.8
ohms
Coil
secondary
N
.A
.
N
.A
.
Table
c
.
Ignition
Coil
Resistance
(M44
Engine)
Terminais
Resistance
(referto
Fig
.
5
.)
Coil
#1
primary
1
(-)
and
2
(+)
0
.4-0
.8
ohms
Coil
#2
primary
6
(-)
and2
(+)
0
.4-0
.8
ohms
Coil
#3
primary
7
(-)
and
2
(+)
0
.4-0
.8
ohms
Coil
#4
primary
5
(-)
and2
(+)
0
.4-0
.8
ohms
Coil
secondary
N
.A
.
N
.A
.
NOTE-
If
a
single
coilís
faulty
on
M44
engines,
the
complete
coil
pack
will
have
to
be
replaced
.
Ignition
coil,
testing
and
replacing
(6-cylinder
engine)
CAUTION-
Use
a
digital
multimeter
for
the
following
tests
.
1.
Remove
plastic
enginecovers
from
top
of
engine
by
prying
off
nut
covers
and
removingcover
mounting
nuts
.
See
113
Cylinder
HeadRemoval
and
Installa-
tion
.
2
.
Disconnect
harnessconnectorfromcof
.
Connect
mul-
timeter
between
terminal
15
(+)
in
connector
and
ground
.
See
Fig
.
6
.
3
.
Turn
ignition
on
and
check
for
batteryvoltage
.
"
If
batteryvoltage
is
not
present,
check
wire
between
terminal
15
and
ignition
switch
.
See
Electrical
Wiring
Diagrams
.
"mozo
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