Temperatura BMW 325i 1998 E36 Workshop Manual
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 176 of 759
130-
3
0
FUEL
INJECTION
Pin
Signal
Component/function
Signal
ECM
PIN
ASSIGNMENTS
Table
1.
ECM
Pin
Assignment-Bosch
DME
M3
.1
1
output
Fuel
pump
relay
control
Fuel
pump
relay
switches
with
engine
runningor
cranking
(crankshaft
position
Signal
mustbe
present
for
relay
switchover)
2
1
output
1
Idle
speed
control
valve
1
Pulsad
ground-
close
signal
(seealsopin29)
3
output
Fuel
injectorcontrol,
cyl
.
1
Pulsedground
(injection
pulsewidth
in
ms)
with
engine
running
4
output
Fuel
injectorcontrol,
cyl
.
3
Pulsedground
(injection
pulsewidth
in
ms)
with
engine
running
5
output
Fuel
injector
control,
cyl
.
2
Pulsedground
(injection
pulse
width
in
ms)
with
enginerunning
6
ground
Ground
Ground
for
fuel
injector
output
stages
7
vacant
-
-
8
output
Check
Engine
Check
éngine
lamp
control
ground
9
vacant
-
-
10
vacant
-
-
11
output
Throttle
valve
position
Load
signal
to
transmission
control
module
12
input
Throttle
position
sensor
Voltage
varies
with
throttle
position
13
output
Mass
air
flow
sensor
Air
flow
sensor
hotwire
burn
off
(voltage
for
0
.5
seconds
after
shutdown)
14
ground
Mass
air
flow
sensor
Ground
for
air
flow
sensor
15
vacant
-
-
16
input
Cylinder
identification
sensor
A/C
voltage
pulse
per
camshaft
revolution
(between
pin
16
and
44)
17
output
Fuel
consumption
(ti)
Fuel
consumption
output
(KVA
Signal)
to
instrument
cluster
18
vacant
-
-
19
vacant
-
-
20
vacant
-
-
21vacant
-
-
22
vacant
-
-
23
output
Ignition
control
(terminal
1),
cyl
.
no
.
2
Primary
Signal,
ignition
coil
cyl
.
no
.
2
24
output
Ignition
control
(terminal
1),
cyl
.
n
o
.
3
Primary
signal,
ignition
coil
cyl
.
no
.
3
25
output
Ignition
control
(terminal
1),
cyl
.
n
o
.
1
Primary
signal,
ignitioh
coil
cyl
.
no
.
1
26
input
Power
supply
(terminal
30)
Battery
voltage
(B+)
at
al¡
times
(terminal
30)
27
output
Main
relay
control
Main
relay
activation
(to
relay
terminal
85)
28
ground
Ground
Ground
for
ECM
and
sensor
shielding
29
output
Idle
speed
control
valve
Pulsed
ground-
open
signal
(see
also
pin
2)
30
vacant
-
-
31
output
Fuel
injector,cyl
.
no
.
5
Pulsedground
(injection
pulsewidth
in
ms),
cyl
.
no
.
5
32
output
Fuel
injector,cyl
.
no
.
6
Pulsedground
(injection
pulse
width
in
ms),
cyl
.
no
.
6
33
output
Fuel
injector,cyl
.
no
.
4
Pulsedground
(injection
pulsewidth
in
ms),
cyl
.
no
.
4
34
ground
Ground
Ground
for
output
stages
35
vacant
36
output
Evaporative
purgevalve
control
Pulsed
ground
with
engine
at
normal
temperature
and
varying
engine
load
37
output
Oxygen
sensor
heater
relay
control
Oxygen
sensor
heater
relayactivation
(ground
at
terminal
85)
38
vacant
-
-
39
vacant
-
-
40
vacant
-
41
input
Mass
air
flow
sensor
Voltage
(+)
42
vacant
-
-
43
ground
Ground
Ground
for
temperatura
sensors
(ECT
sensor,
IAT
sensor,
TP
sensor)
44
input
Cylinder
identification
sensor
A/C
voltagepulseper
camshaft
revolution
(between
pin
16
and
44)
Page 179 of 759
Table
j.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
Pin
~
Signal
1
Componentffunction
1
signal
FUEL
INJECTION
130-
33
45
ground
Ignition
circuit
shield
Ground
shieldfor
ignition
circuit
monitoring
46
output
Fuel
consumption
(KVA
signal)
To
instrument
cluster
47
output
Crankshaft
rpm
Engine
speed
(TD)
signal
to
instrument
cluster
48
output
A/C
compressor
control
A/C
compressor
relay
terminal
85
49
vacant
-
-
50
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
51
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
52
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignition
coil
3
53
vacant
-
-
54
input
Power
supply
Battery
voltagefrom
main
relay
(terminal
87a)
55
ground
Ground
Ground
for
ignition
control
56
input
Power
supply
(terminal15)
Batteryvoltage
with
key
on
or
engine
running
57
input
Ignition
timing
intervention
From
A/T
control
module
58
vacant
-
-
59
output
Throttleposition
sensor
(TPS)
Voltage
supply
to
TPS
(5
VDC)
60
input
Programming
voltage
Data
link
connector
61
vacant
-
-
62
vacant
-
-
63
vacant
-
-
64
input
A/C
on
signal
From
integrated
climate
control
module
65
input
A/C
pressure
signal
From
integrated
climate
control
module
via
A/C
pressure
switch
66
input
On-board
computer
Drive-away
protection
enable
(starter
immobilization
relay)
67
vacant
-
-
68
vacant
-
-
69
input
Knock
sensor
#2
(cyl
.
4,5,
6)
Knock
sensor
#2
signal
70
input
Knock
sensor
#1
(cyl
.
1,2,
3)
Knock
sensor
#1
signal
71
ground
Ground
Ground
for
knock
sensors
and
shields
72
vacant
-
-
73
input
Throttleposition
sensor
(TPS)
Throttleposition
signal
74
vacant
-
75
vacant
-
-
76
vacant
-
77
input
Intakeair
temperatura
Intakeair
temperatura
sensor
(0-5
VDC)
78
input
Engine
coolant
temperature
Engine
coolant
temperature
sensor
(0-5
VDC)
79
vacant
-
80
vacant
-
-
81
input
Automatic
transmission
gear
positionlneutral
A/T
parkor
neutral
position
signal
safetyswitch
82
vacant
-
-
83
vacant
-
-
84
vacant
-
-
85
vacant
-
-
86
vacant
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)
signal
to
pin
15
in
Data
link
connector
88
input/output
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
20
in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 181 of 759
Table
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
(continued)
Pin
I
Signal
1
Componentltunction
1
Signal
45
I
output
I
Mass
air
flow
meter
I
Intake
airSignal
46
output
Oxygen
sensor
(monitoring
sensor)
Oxygen
sensor
control
47
not
used
-
48
not
used
-
49
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
50
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
51
not
used
-
52
not
used
-
53
input
Throttleposition
sensor
Throttleposition
Signal
54
input
Power
supply
Batteryvoltage
from
main
relay
(terminal
87)
55
ground
Ground
Ground
for
ECM
56
input
Power
supply
(terminal
15)
Battery
voltage
with
key
on
or
engine
running
57
output
Activate
cooling
fan
(man
.
trans
.)
control
Normal
speed
relay
58
not
used
-
-
59
not
used
-
-
60
input
Programming
voltage
Programming
voltage
via
data
link
connector,
pin
18
61
output
Evaporative
emissionvalve
Evaporative
emission
valve
control
62
vacant
-
-
63
output
Fuel
pump
relay
Fuel
pump
relay
control
64
not
used
-
65
not
used
-
-
66
not
used
-
-
67
not
used
-
-
68
input
Signal
above
80°C(man
.
tran
.)
Double
temperature
switch
69
input
Automatic
climate
control
Automatíc
climate
control
70
input
Knock
sensor
#1
(cyl
.
1,2)
Knock
sensor
#1
Signal
71
ground
Ground
Ground
for
analog
signals
and
knock
sensors
72
not
used
-
-
73
not
used
-
-
74
input
Engine
coolant
temperature
sensor
Engine
coolant
temperatura
Signal
75
not
used
-
-
76
not
used
-
-
77
output
Oxygen
sensor
(regulating
sensor)
Oxygen
sensor
control
78
input
Crankshaft/rpm
sensor
Crankshaft
position/rpmSignal
79
input
ABS
or
traction
control
ABS
or
AST
control
80
input
Engine
speed
Engine
speed
Signal
81
not
used
-
-
82
not
used
-
-
FUEL
INJECTION
130-
3
5
83
input
On-board
computar
From
On-boardcomputer
(terminal
4)
84
not
used
-
-
85
not
used
-
-
86
not
used
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)signal
to
pin
15
in
Data
link
connector
88
output
I
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
17in
Data
link
connector
ECM
PIN
ASSIGNMENTS
Page 205 of 759
Fig
.
19
.
Coolant
pump
being
removed
.
Thread
two
M6
bolts
(arrows)
in
evenly
to
withdraw
pump
.
(Thermostat
and
hoseshavebeen
removed
tor
visual
access
.)
8
.
Installation
is
reverse
of
removal
.
"
Be
sure
to
replace
O-ring
and
gaskets
.
"
Coat
O-ring
with
lubricant
during
installation
.
Tightening
Torque
"
Coolant
pump
to
timing
chaincover
M6
...
.
...................
..
.
.
10
Nm
(89
in-lb)
M8
.
..
.
....................
.
.
.
22
Nm
(17
ft-Ib)
"
Coolant
pump
pulley
to
coolant
pump
.................
10
Nm
(89
in-lb)
RADIATOR
SERVICE
Radiator,
removing
and
installing
1
.
Drain
radiator
as
described
earlier
.
WARNING
-
Allow
cooling
system
to
cool
before
opening
ordraining
system
.
2
.
Remove
primary
cooling
fan
(belt-driven
or
electric)
as
described
earlier
.
3
.
Disconnect
coolingfan
and
leve¡
sensor
harness
con-
nectors
from
bottom
of
radiator,
where
applicable
4
.
Disconnect
harness
connector
from
auxiliary
fandual
temperature
switch
.
See
Fig
.
20
.
5
.
Disconnect
all
coolant
hoses
from
radiator
.
RADIATOR
AND
COOLING
SYSTEM
170-11
0012500
Fig
.
20
.
Cooling
fan
dual
temperatura
switch
(arrow)
on
right
sido
of
radiator
.
6
.
Where
applicable,
disconnectautomatic
transmission
fluid
(ATF)
cooler
lines
from
radiator
.
See
Fig
.
21
.
Fig
.
21
.
Automatic
transmission
fluid
(ATF)
linos
at
radiator
.
7
.
Carefully
pryout
radiator
retaining
clips
from
top
of
ra-
diator
.
See
Fig
.
22
.
8
.
Pul¡
radiator
up
and
out
of
car
.
NOTE-
The
radiator
rests
ontwo
rubber
mounts
.
Check
that
the
mounts
do
not
stick
to
the
bottomof
the
radiator
.
RADIATOR
SERVICE
Page 326 of 759
510-4
EXTERIOR
TRIM,
BUMPERS
Fig
.
8
.
Bumper
cover
retaining
screws
(arrows)
in
left
wheel
weil
.
7
.
Disconnect
harnessconnectors
at
outside
temperature
0013052
sensor
at
rear
of
left
side
of
bumperand
temperatura
Fig
.
9
.
Front
bumper
impact
absorber
mounting
nuts
(A)
and
switch
at
rear
of
right
side
of
bumper
(if
applicable)
.
bumper
bracket
hardware
(B)
.
8
.
Slide
bumper
straight
off
sida
brackets
.
9
.
Installation
is
reverse
of
removal,
notingthe
following
:
When
removing
and
installing
therear
bumper
or
its
compo-
"
Slide
side
brackets
on
bumper
and
body
carefully
to-
nents,
referto
Fig
.
10
.
gether
.
"
Make
sure
tabs
on
trim
strip
engage
slots
in
bumper
1
.
Raise
and
properly
support
vehicle
.
correctly
.
Tightening
Torque
"
Bumper
to
bumper
bracket
(M8
nut)
............
...
.
.
22
Nm
(16
ft-Ib)
2
.
Working
under
bumper,
remove
screws
or
expansion
Front
bumper
impact
absorber,replacing
rivetsat
corners
and
middle
of
lower
bumper
panel
.
Pull
panel
backward,
uncoupling
it
from
bumper
cover
.
See
Thebumper
mounting
bracket
and
impact
absorber
mount-
Fig
.
11
.
ing
hardware
are
accessible
with
the
Font
bumper
removed,
as
described
above
.
See
Fig
.
9
.
3
.
Remove
bumper
cover
expansion
rivets
and
screws
in-
side
left
and
right
rear
wheel
wells
.
NOTE
-
Install
the
bumper
bracket
boltwith
thread
locking
com-
pound
suchas
Loctite
8
270
or
equivalent
.
Tightening
Torques
"
Bumper
bracket
to
impact
absorber
(M10
nut)
.
..
.
...
.............:.
55
Nm
(41
ft-Ib)
"
Impact
absorber
to
chassis
(M6
nut)
...
9
Nm
(7
ft-Ib)
BUMPERS
Rear
bumper,
removing
and
installing
WARNING
-
Make
sure
that
the
car
is
firmly
supported
on
jack
stands
designad
for
the
purpose
.
Place
the
jack
stands
beneath
a
structural
chassis
point
.
Do
not
place
jack
stands
under
suspension
parts
.
4
.
Remove
left
and
right
bumper
bracket
mounting
bolts
and
remove
bumper
.
See
Fig
.
12
.
5
.
Installation
is
reverse
of
removal
.
NOTE-
Install
the
bumper
bracket
bolt
with
thread
locking
com-
pound
suchas
Loctite®270
or
equivalent
.