1995 BMW 318i Electrical system

Sensor

fan

Fig
.
25
.
Digital
display
A/C
control
head
components
.

2
.
Unscrew
left
and
right
screws
retaining
control
head
to
control
module
.
Press
retaining
clips
and
release
front
plate
from
control
head
.
Remove
A/C
control
module
from
control
head
housing
.

Sensor
fan
for
interior
temperature,

repiacing

A
small
electricfan,installed
in
the
A/C
control
head,
draws
cabin
air
past
the
climate
control
temperature
sensor
.

1.
Remove
A/C
control
head
as
described
earlier
.

2
.
Rotary-knob
control
head
:
Disconnect
electrical
con-
nector
from
top
of
control
head
housing
.
Pry
open
plas-

tic
housing
and
remove
sensor
fan
.
See
Fig
.
26
.

0013181

Fig
.
26
.
Sensor
fan
(A)
and
harness
(B)
in
back
of
A/C
control
head
(rotary-knob
control
head
shown)
.

3
.
Digital
display
models
:
Disconnect
electrical
harness

connector
from
control
head
housing
.
Remove
screws

holding
sensor
fan
to
bottom
of
control
moduleand
re-
move
.
Refer
to
Fig
.
25
.

4
.
Installation
is
reverse
of
removal
.

HEATING
AND
AIR
CONDITIONING



640-
9

Heater
and
A/C
Air
Distribution
Motors

The
recirculation,
fresh
air
and
othervent-duct
flaps
are
controlled
electrically
via
a
series
of
air
distribution
actuating
motors
.
Cars
with
the
rotary-knob
control
head
use
three
elec-
tromechanical
motors,
each
held
in
place
via
a
small
plastic
clip
.
See
Fig
.
27
.

Rightside
of
heater
box
l

Fig
.
27
.
Location
of
early
production
air
distribution
motors
(arrows)
.

Later
systems
(with
the
digital
display
control
head)
use
five
distribution
motors,
four
of
which
are
digítally
controlled
.
See
Fig
.
28
.

HEATER
AND
CONTROLS

Fig
.
36
.
6-cylinder
engine
belt
diagram
:
To
remove
A/C
belt,
lever
ten-
sioner
(A)
in
clockwise
direction
using
long-handled
wrench
or
breaker-bar
.

6
.
Disconnect
electrical
harness
connector
from
com-
pressor
.

7
.
Remove
A/C
pressure
hose
and
suction
hose
flange



10
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
bolts
from
compressor
.
Plug
hoses
immediately
See



Recharge
system
following
equipment
manufacturer's

Fig
.
37
.



instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

0011879

Fig
.
37
.
A/
C
compressor
pressure
hose
(A)
and
suction
hose
(B)
.
(6-
cylinder
engine
shown
.
4-cylinder
engine
is
similar
.)

HEATING
AND
AIR
CONDITIONING



640-
1
3

Fig
.
38
.
A/
C
compressor
mounting
boits
(arrows)
.

9
.
Installation
is
reverseof
removal
.

CAUTION
-

"
Always
replaceO-rings
when
reconnecting
re-
frigerantfines
.

"
When
installlng
a
new
compressor
always
re-
place
receiverldrier
unit
.

Tightening
Torques

"
A/C
compressor
to
engine
block
....
22
Nm
(17
ft-Ib)
"
A/C
line
flange
to
A/C
compressor
5/8
in
.
fine
.
......
.....
....
.
.....
20
Nm
(15
ft-Ib)

3/4
in
.
fine
.......
.....
..........
39
Nm
(29
ft-Ib)

7/8
in
.
fine
...
....
.....
..........
42
Nm
(31
ft-Ib)

11/16
in
.
fine
.....
..
..
..
...
.
.....
48
Nm
(35
ft-Ib)

A/C
Compressor
Clutch

The
compressor
clutch
can
be
replaced
without
disturbing

thesealed
refrigerant
system,
although
clearances
in
the
six-

cylinder
cars
may
be
very
tight
.
Detach
the
compressor
from

the
compressor
bracket
togain
extra
clearance
.

8
.
Remove
compressor
mounting
boits
.
See
Fig
.
38
.
Re-



Typical
A/C
compressor
and
clutch
is
shown
in
Fig
.
39
.
move
compressor
by
pulling
downward
from
under-

neath
car
.



Remove
driveplate
and
pulley
to
access
clutch
magnetic

winding
.
See
Fig
.
40
.

AIR
CONDITIONING

Fig
.
42
.
Upper
A/C
condensermounting
bolts
(arrows)
.

8
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
Recharge
system
following
equipment
manufacturer's
instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

A/C
receiver/drier,
replacing

The
A/C
receiver/drier
is
mounted
in
the
front
right
cornee
of
the
engine
compartment
behind
the
headlight
assembly
.

CAUTION-

The
receiver/drier
must
be
replaced
when
-There
is
dirt
in
the
AIC
system
-The
compressor
has
seized
or
has
been
re-
placed
for
any
reason
-The
condenser
or
evaporator
are
replaced
for
any
reason
-The
AIC
system
is
leaking
and
there
is
no
more
refrigerant
-The
AIC
system
was
open
for
24
hours
or
more
.

1
.
Following
manufacturer's
instructions,
connectan
ap-

proved
refrigerant
recovery/recycling/recharging
unit
to

A/C
system
and
discharge
system
.

2
.
Remove
right
headlight
assembly
.
See
630
Exterior
Lighting
.

CAUTION-
3
.
Disconnect
A/C
electrical
harness
connectors
.
See
Fig
.



Always
replaceO-rings
when
reconnecting
refrig-
43
.



erant
lines
.

4
.
Remove
refrigerant
pressure
lines
from
receiver/drier
.

Plug
lines
immediately
.

5
.
Remove
receiver/drier
mounting
bolts
.

0013182

6
.
Remove
underbody
splash
shield
on
passenger
side
.

See
Fig
.
44
.

7
.
Remove
passenger
side
brake
cooling
duct
.
Discon-

nect
outside
temperature
sensor
harness,
if
applicable
.

HEATING
AND
AIR
CONDITIONING



640-15

0012669

Fig
.
43
.
A/
C
receiver/drier
electrical
harness
connectors
(A),
pressure
line
retaining
bolts
(B),
andmounting
bolts
(C)
.

0012668
Fig
.
44
.
Passenger
sidesplash
shield
retaining
screws
(arrows)
.

8
.
Push
receiver/drier
down
andremove
from
underneath
car
.
Make
sure
that
receiver/drier
is
clear
of
any
electri-
cal
harnesses
.

9
.
Installation
is
reverse
of
removal
.

10
.
Before
recharging,
evacuate
system
for
at
least
30
min
.

Recharge
system
following
equipment
manufacturer's

instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

AIR
CONDITIONING

CAUTION
-

Always
replace
O-rings
when
reconnecting
refrig-
erant
fines
.

9
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
Recharge
system
following
equipment
manufacturer's
instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

A/C
evaporator,
removing
and
installing

1
.
Followingmanufacturer's
instructions,
connectanap-proved
refrigerant
recovery/recycling/recharging
unit
to
A/C
system
and
discharge
system
.

2
.
Remove
complete
heater
boxas
described
earlier
.

3
.
Remove
expansion
valve
as
described
earlier
.

4
.
Unfasten
evaporator
sensor
electrical
harness
connec-
tor
and
puli
out
sensor
from
ieft
side
of
heater
box
.
See
Fig
.
50
.

Fig
.
49
.
Pull
out
evaporator
sensor
from
housing
in
direction
of
arrow
.

5
.
Remove
rear
heater
box
cover
.

6
.
Remove
clips
retaining
lower
evaporator
housingcover
.
Tilt
outheater
core,
then
pull
evaporator
out
of
housing
.

7
.
Installation
is
reverse
of
removal
.

CAUTION
-

Always
reptace
O-rings
when
reconnecting
refrtg-
erant
fines
.

8
.
Before
recharging,
evacuate
system
for
at
least
30
min
.

Recharge
system
following
equipment
manufacturer's
instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

HEATING
AND
AIR
CONDITIONING



640-17

8
.
Installation
is
reverse
of
removal
.



A/C
evaporator
temperature
sensor,

replacing

ou12b46

The
evaporator
temperature
sensor
is
mounted
in
the
left
(driver)
side
of
theheater
box
behind
thecenter
console
.

1
.
Remove
lower
dash
panel
and
knee
boister
on
driver
side
.
See
513
Interior
Trim
.

2
.
Remove
left
footwell
ventilation
duct
byremoving
re-
taining
rivet
in
bottom
of
duct
.
Pull
it
down
and
away
from
heater
box
.
See
Fig
.
50
.

Fig
.
50
.
Left
footwellventilatíon
duct
(arrow)
.

0o1300ba

3
.
Disconnect
sensor
electrical
connector
from
heater
box
.
Pull
sensor
straight
out
of
heater
box
.
Refer
to
Fig
.
49
.

4
.
Installation
is
reverse
of
removal
.
Table
c
.
lists
evapo-

rator
temperature
sensor
test
values
.

Tablec
.
Evaporator
Temperature
Sensor

Test
Values

Test
temp
.



Resistance

23°F
(-5°C)



11
.4
-11
.9
k
ohms

32°F
(0°C)



8
.8
-
9
.2
k
ohms

41
°F
(5°C)



6
.8
-
7
.2
k
ohms

50°F
(10°C)



5
.3-5
.6
k
ohms

59
°
F
(15°C)



4
.2
-4
.5
k
ohms

68°F
(20°C)



3
.3
-
3
.6
k
ohms

77°F
(25°C)



2
.6-2
.9
k
ohms

86°F
(30°C)



2
.1
-
2
.3
k
ohms

95°F
(35°C)



1
.7
-1
.9
k
ohms

AIR
CONDITIONING

650-2
RADIO

"
A
320-watt
Harmon-Kardon
ten
speaker
system,
including



RADIO
AND
SPEAKER
SERVICE
a
separate
high
power
multi-channel
audio
amplifier
and
two
sub-woofers
.
In
this
system,
thebass
and
volume
out-

puts
from
the
selected
audiosource
automatically
com-



Radio,
removing
and
installing

pensate
for
vehicle
speed,
making
constant
volume

adjustments
unnecessary
.
An
additional
feature
ofthis



CAUTION-
sound
system
is
the
ability
to
switch
from
normal
left-right



"
Before
beginning
work
on
the
radio
or
sound
stereo
into
Spatial
Enhancement
Mode,
which
produces
a



system,
verify
that
the
radio
is
an
original
equip-
fuller,
rounder
sound
.
See
Fig
.
3
.



ment
BMW
radio
and
that
thewiring
harness
has
not
been
modified
.
TheE36
radio
is
also
equipped
with
a
built-in
anti-theft
sys-

tem
.
lf
power
is
removed
from
the
radio
circuitry
by
removing

the
radio
electrical
connectors,
or
by
disconnecting
the
bat-
tery,
the
radio
is
rendered
inoperative
.
The
radio
is
not
perma-

nently
damaged,
and
proper
operation
can
be
restored
by

entering
the
radio
anti-theft
code
.

Fig
.
3
.
Ten
speaker
sound
system
.

RADIO
AND
SPEAKER
SERVICE

"
Servicing
of
aftermarket
sound
equipment
should
be
referredto
an
authorized
agent
of
the
equip-
ment's
manufacturer
.

"
Do
not
remove
radio
or
disconnect
the
batterywithout
first
obtaining
the
anti-theft
code
.

1.
Carefully
pry
open
small
square
covers
at
left
and
right

sides
of
radio
.

1
.
Disconnect
negative
(-)
cable
from
battery
and
cover

negative
terminal
with
insulating
material
.

CA
UTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.

2
.
Remove
driver
sideairbag
from
steering
wheel
.
See

Driver
side
airbag,
removing
and
installing
in
this

repair
group
.

3
.
With
wheels
facing
straight
ahead
and
steering
wheel

centered,
remove
steering
wheel
.
See320
Steering
and
Wheel
Alignment
.

4
.
Remove
contact
ring
cover
(flat
plastic
ring
containing

warning
text)
from
steering
wheel,
íf
applicable
.

5
.
Disconnect
ground
wire,
if
applicable

6
.
Lift
out
plastic
lock
from
steering
wheel,
if
applicable
.

See
Fig
.
2
.

0011903

Fig
.
2
.



Airbag
contact
ring
lock(arrow)
.
Pry
out
lock
and
remove
spríng
from
behind
lock
.
Some
airbag
steering
wheels
are
not
equipped
with
contact
ring
lock
.

WARNING
-

"
The
contact
ring
lock
holds
the
contact
ring
in
the
centered
position
.
Once
the
lock
is
removed,
the
contact
ring
is
free
to
rotate
.
Do
not
allow
the
con-

tact
ring
to
rotate
once
the
lock
is
removed
.

"
If
the
contact
ring
is
accidentally
rotated
outof
center,
turn
the
ring
either
fully
clockwise
orcoun-
terclockwise,
then
turn
in
the
opposite
direction
3
complete
revolutions
until
the
alignment
arrow
canbe
seen
through
the
lock
opening
.

AIRBAG
SYSTEM
(SRS)



721-
3

Airbagcontact
ring,
replacing



7
.
Remove
mounting
nutsor
screws
from
contact
ring
.

See
Fig
.
3
.
Disconnect
wire
lead(s)
andremove
contact

The
airbag
contact
ring
is
mounted
to
the
rear
of
the
steer-



ring
from
rear
of
steering
wheel
.

ing
wheel
and
is
made
up
of
a
wireribbon
that
cofs
and
un-

coils
as
the
steering
wheel
is
tumed
.
The
contact
ring
assures
continuous
electrical
contact
to
the
driver
side
airbag
unit
.

Fig
.
3
.



Airbag
contact
ring
mounting
fasteners(arrows)
.

8
.
Installation
is
reverse
ofremoval,noting
the
following
:

"
Coat
horn
slip
ring
(electrical
contact
ring)
with
CRC
®
copper
paste
before
installing
steering
wheel
.

"
Press
on
lower
lock
until
it
ís
fully
engaged
.

"
When
installing
contact
ringlock,
make
sure
lock

spring
engages
pins
on
lock
and
lock
cover
.

"
Special
instructions
apply
when
installing
airbag

equipped
steering
wheel
.
See320
Steering
and

Wheel
Alignment
.

Early
cars
(through
1993)
:

"
Route
wiring
lead
for
horn
through
squareopening
in

steering
wheel
.

"
When
installing
a
new
contact
ring
from
BMW,
remove

locking
screw
after
installing
the
contact
ringto
steer-

ing
wheel
.
See
Fig
.
4
.

"
Lock
contact
ring
mounting
fasteners
in
place
using

lacquer
paint
or
varnish
.

0011904

Fig
.
4
.



Airbag
contact
ring
locking
screw
(arrow),
as
installed
on
new

replacement
part
from
BMW
(early
production
cars)
.

AIRBAG
SENSORS
AND
ELECTRONICS

721-
6



AIRBAG
SYSTEM
(SRS)

5
.
Carefully
lift
airbag
unit
off
steering
wheel
and
discon-



6
.
Installation
is
reverse
of
removal
.
Tighten
right
side
nect
orange
harness
connector
from
rear
of
airbag
unit
.



screw
on
airbag
first
(as
viewedfrom
driver's
seat),

See
Fig
.
10
.



then
left
side
screw
.

NOTE-



NOTE-

In
some
models,
theairbag
electrical
connection
to
the



If
there
is
no
electrical
harness
connector
between
the
steering
wheel
isvia
aplug
in
back
of
the
airbag
unit
.



airbag
and
the
steering
wheel,
be
sure
to
fit
the
push
There
is
no
wire
harness
to
disconnect
.



in
electrical
plug
in
back
of
the
airbag
finto
the
proper
re-
ceptacle
in
the
steering
wheel
.

Fig
.
10
.
Driver
sideairbag
unit
harness
connector
(arrow)
.

AIRBAGS

WARNING
-

"
Store
the
removed
airbag
unit
with
the
horn
pad
facing
up
.
If
stored
facing
down,
accidental
de-
ployment
couldpropel
it
violently
into
the
air,
causing
injury
.

"
Once
an
airbag
is
removed,
the
car
must
not
be
driven
.

"
Do
not
connect
the
battery
with
the
airbag
dis-
connected
.
A
fault
code
will
be
stored,
setting
off
the
SRS
warning
light
.
Special
tools
are
needed
to
reset
the
fault
memory
.

"
Special
instructions
apply
when
installing
an
air-
bag
equipped
steering
wheel
.
See
320
Steering
and
Wheel
Alignment
.

"
Once
the
airbag
unit
is
installnd
and
all
other
ser-vice
procedureshave
been
completed,
start
the
engíne
and
check
that
the
SRS
warning
light
goes
out
.
If
the
warning
light
stays
on,
the
SRS
system
will
not
function
as
designed
.
Have
the
system
diagnosed
and
repaired
by
an
authorized
BMW
dealer
.

0013184

Tightening
Torque

"
Airbag
unitto
steering
wheel
........
8
Nm
(71
in-lb)

Passenger
side
airbag,

removing
and
installing

1
.
Disconnect
negative
(-)
cable
from
battery
and
cover
negative
terminal
with
insulating
material
.

2
.
Remove
glove
compartment
.
See
513
Interior
Trim
.

3
.
Lift
cover
from
topof
passenger
sideairbag
on
dash-
board
.
See
Fig
.
11
.

0013108
Fig
.
11
.
After
removing
glove
compartment,
lift
out
passenger
side
air-
bag
cover
.
Note
airbag
mounting
bolts
(A)
and
airbag
electri-
cal
connector
(B)
.

4
.
Remove
passenger
sideairbag
mounting
bolts
.
Dis-
connect
electrical
harness
connector
from
rear
of
air-
bag
unit
and
remove
airbag
.

5
.
Installation
is
reverse
of
removal
.
Make
sure
wiring
har-
ness
is
not
pínched
when
installing
airbag
unit
in
dash-board
.

Front
side-impact
airbag,

removing
and
installing

1
.
Disconnect
negative
(-)
cable
from
battery
and
cover

negative
terminal
with
insulating
material
.

CA
UTION-



"
Store
the
removed
airbag
unit
with
the
soft
pad
Prior
to
disconnectiog
the
battery,
read
the
battery



facing
up
.
ff
stored
facíng
down,
accidental
de-
disconnection
cautions
given
at
the
front
of
this



ployment
could
propel
it
violently
into
the
air,
manual
on
page
viii
.



causing
injury
.

2
.
Remove
inside
door
panel
as
described
in
411
Doors
.

Remove
vapor
shield
.

3
.
Disconnect
electrical
harness
connectorfrom
door-

mounted
airbag
unit
.
See
Fig
.
12
.

WARNING
-

The
plug
connector
insidethe
door
is
not
marked
in

orange,
unlike
other
SRS
connectors
in
the
car
.

Fig
.
12
.
Front
side-impact
airbag
(inner
door
panel
removed)
.
A
is

electrical
harness
connector
.

AIRBAG
SYSTEM
(SRS)



721-
7

CAUTION-

"
The
electrical
harness
connector
of
the
side-im-
pact
airbag
unit
may
be
either
on
the
sideof
the
unít
or
in
the
back
When
removing
and
installing
the
unit,
pay
attention
to
the
routing
of
the
har-
ness
to
avoid
kinks
orbreaks
in
the
wire
.

4
.
Remove
mounting
screws
andremove
airbag
from

door
.

5
.
Installation
is
reverse
of
removal
.

WARNING
-

The
side-impact
airbag
mounting
screws
must
al-
ways
be
replaced
any
time
they
are
removed
.
Usenew
screws
with
factory-applied
locking
sealer
.

Tightening
Torque

"
Side-impact
airbag
to
door



..
.....
8
.5
Nm
(75
in-lb)

AIRBAGS