1997 BMW 328i Ground

600-
4



ELECTRICAL
SYSTEM-GENERAL

Voltage
and
Voltage
Drops

The
wires,
connectors,
and
switches
that
carry
current
are

designed
with
very
low
resistance
so
that
current
flows
with
a

minimum
loss
of
voltage
.
A
voltage
drop
is
caused
by
higher
than
normal
resistance
in
a
circuit
.
This
additional
resistance

actually
decreases
or
stops
the
flow
of
current
.
A
voltage
drop

can
be
noticed
byproblems
ranging
fromdim
headlights
to
sluggish
wipers
.
Some
common
sources
of
voltage
drops
are
corroded
or
dirty
switches,
dirty
or
corroded
connections
or

contacts,
and
loose
or
corroded
ground
wires
and
ground
con-

nections
.

A
voltage
drop
test
is
a
good
test
to
make
if
current
is
flowing
through
the
circuit,
butthe
circuit
is
not
operating
correctly
.
A
voltage
drop
test
will
help
to
pinpoint
a
corroded
ground
strap
or
a
faulty
switch
.
Normally,
there
should
be
less
than
1
volt

drop
across
most
wires
or
closed
switches
.
A
voltage
drop
across
a
connector
or
short
cable
shouldnot
exceed
0
.5
volts
.

Voltage,
measuring

1
.
Connect
digital
multimeternegative
lead
to
a
reliable
ground
point
oncar
.

NOTE-

The
negative
(-)
battery
terminal
is
alwaysa
good
ground
point
.

2
.
Connect
digital
multimeter
positive
lead
to
point
incir-
cuit
you
wish
to
measure
.
See
Fig
.
1
.
If
a
reading
is
ob-
tained,
current
is
flowing
through
circuit
.

NOTE-

The
voltage
reading
shouldnot
deviate
more
than
1
volt
from
the
voltage
at
the
battery
.
If
the
voltage
drop
is
more
than
this,
check
for
acorroded
connector
or
cose
ground
wire
.

ELECTRICAL
TROLIBLESHOOTING

from
Battery

Fig
.
1
.



Digital
multimeterbeing
used
to
test
voltage
.

No
voltage
r_l

-1
Load

LJ

Switch

NOTE-

The
maximum
voltage
drop
in
an
automotive
circuit,
as
recommended
by
the
Society
of
AutomotiveEngineers
(SAE),
is
as
follows
:
0
voltsfor
small
vire
connections
;
0
.1
Volts
for
high
current
connections
;
0
.2
volts
for
high
current
cables
;
and
0
.3volts
for
switch
or
solenoidcon-
tacts
.
On
longer
wires
or
cables,
the
drop
may
be
slight-ly
higher
.
In
any
case,
a
voltage
drop
of
more
than
1.0volt
usually
indicates
a
problem
.

0013238

NOTE-

"
A
voltage
drop
test
is
generally
more
accuratethan
a



Voltage
drop,
testing

simple
resistance
check
because
the
resistances
in-
volvedare
often
too
small
to
measure
with
most
ohm-



Voltage
drop
can
only
be
checked
when
current
is
running
meters
.
For
example,
a
resistance
as
small
as0
.02



through
the
circuit,
suchasby
operating
the
starter
motor
or
ohms
would
results
in
a
3
volt
drop
in
a
typical
150



turning
onthe
headlights
.
A
digital
multimeter
should
beused
amp
starter
circuit
.
(150
amps
x
0
.02
ohms
=3
volts)
.



lo
ensure
accurate
readings
.

"
Keep
in
mind
that
voltage
with
the
key
on
and
voltage
with
the
engine
running
arenotthe
same
.
With
the
ig-



1
.
Connect
digital
multimeter
positive
lead
to
positive
(+)
nition
on
and
the
engine
off
(battery
voltage),
voltage



battery
terminalor
a
positive
power
supply
close
lo
bat
should
be
approximately
12
.6volts
.
With
the
engine



tery
source
.
running
(charging
voltage),
voltage
should
be
approx-
imately
14
.0
volts
.
Measure
voltage
at
the
battery
with



2
.
Connect
digital
multimeter
negativelead
to
other
end
of
the
ignition
on
and
then
with
the
engine
running
to
get



cable
orswitch
being
tested
.
See
Fig
.
2
.
exact
measurements
.

3
.
With
power
on
and
circuit
working,
meter
shows
volt-
age
drop
(difference
between
two
points)
.
This
value
should
not
exceed
1
volt
.

Continuity,
checking
Short
Circuits

from
Battery

CAUTION-

Use
only
a
high
quality
digital
ohmmeter
having
high
input
impedance
when
checking
electronic
componente
.
The
internal
power
source
used
in
most
analog
(swing-need1e)
meterscan
damage
solidstate
components
.

0013239

Fig
.
2
.



Digital
multimeter
being
used
to
check
for
voltage
drop
across
a
switch
.

The
continuity
test
can
beused
to
check
a
circuit
or
switch
.
Because
most
automotive
circuits
are
designed
to
have
little

or
no
resistance,
a
circuit
or
part
of
a
circuit
canbe
easily

checked
for
faults
using
an
ohmmeter
.
An
open
circuit
or
a
cir-

cuit
withhigh
resistance
will
not
allow
current
to
flow
.
A
círcuit
with
little
or
no
resistanceallows
current
to
flow
easily
.

When
checking
continuity,
the
ignition
should
be
off
.
On
cir-
cuits
that
are
powered
at
all
times,
the
battery
should
be
dis-
connected
.
Using
the
appropriate
wiring
diagram,
a
circuit
can
be
easily
tested
for
faulty
connections,
wires,
switches,
relays,
and
engine
sensorsby
checking
forcontinuity
.
For
a
continu-
ity
check
on
a
brake
light
switch,
see
Fig
.
3
..

A
short
circuit
is
exactly
what
the
narre
implies
.
The
circuit
takes
a
shorter
paththan
it
was
designed
to
take
.
The
most

common
short
that
causes
problems
is
a
short
to
ground

where
the
insulation
on
a
positive
(+)
wire
wears
away
and
the

metal
wire
is
exposed
.
When
the
wire
rubs
against
a
metal

partof
thecar
or
other
ground
source,
the
circuit
is
shorted
to
ground
.
If
the
exposed
wire
is
live
(positive
battery
voltage),
a

Puse
will
blow
and
the
circuit
may
possibly
be
damaged
.

ELECTRICAL
SYSTEM
-
GENERAL
600-
5

Brake
light
switch

Brake
pedal
in
rest
position

Q

Brake
pedal
depressed
Brake
light
switch

Fig
.
3
.



Brake
light
switchbeing
tested
for
continuity
.
With
brake
ped-
alin
rest
position
(switch
open)
there
is
no
continuity
(infinite
ohms)
.
With
pedal
depressed
(switch
closed)
there
is
continu-
ity
(zero
ohms)
.

Shorts
to
groundcanbe
located
with
a
digital
multimeter
.
Short
circuits
are
often
difficult
to
locate
and
may
vary
in
na-
ture
.
Short
circuits
can
befound
using
a
logical
approach
based
onthe
current
path
.

CAUTION
-

"
On
circuits
protected
with
high
rating
fuses
(25
amp
and
greater),
the
wires
or
circuit
compo-
nents
may
be
damaged
before
the
fuse
blows
.
Always
check
for
damage
before
replacing
fuses
of
this
rating
.

"
When
replacing
blown
fuses,
use
only
fuses
hav-
ingthe
correct
rating
.
Always
confirm
the
correct
fuse
rating
printed
on
the
fuselrelay
panelcover

DC

ELECTRICAL
TROUBLESHOOTING

00-
6



ELECTRICAL
SYSTEM-GENERAL

Short
circuit,
testing
with
ohmmeter



Short
circuit,
testing
with
voltmeter

1
.
Remove
blown
fuse
from
circuit
and
disconnect
cables



1
.
Remove
blown
fusefrom
circuit
.

from
battery
.
2
.
Disconnect
harness
connector
from
circuifs
loador

2
.
Disconnect
harness
connector
from
circuit's
loador



consumer
.

consumer
.

3
.
Using
an
ohmmeter,
connect
one
test
lead
to
loadside

of
f
use
terminal
(terminal
leading
to
circuit)
and
the
oth-

ertest
lead
to
ground
.
See
Fig
.
4
.

Load
disconnected
from
Battery

LO

n
I



~



Shotrouit
vu
.uto
earthth

Switch

Load

0013241

Fig
.
4
.



Digital
multimeter
being
usedasan
ohmmeter
to
find
short

circuit
.

4
.
lf
there
is
continuity
to
ground,
there
is
a
short
to

ground
.

ELECTRICAL
TROUBLESHOOTING

NOTE-

Most
fuses
power
more
than
one
consumer
.
Be
sure
aff

consumers
are
disconnected
when
checking
for
a
short
circuit
.

3
.
Using
a
voltmeter,
connect
test
leads
across
f
use
termi-

nals
.
See
Fig
.
5
.
Make
sure
power
is
present
ín
circuit
.

lf
necessary
turn
keyon
.

~2
.U

from
Battery

Load
disconnected

Short-circuit
to
earth

I



Fuse
box

0013240

5
.
If
there
is
no
continuity,
work
from
wire
harness
hearest



Fig
.
5
.



Digital
multimeter
being
usedas
a
voltmeter
to
find
short
cir

to
fuse/relay
panel
and
move
or
wiggle
wireswhile
ob-



cuit
.

serving
meter
.
Continue
to
movedown
harness
until

meter
displays
a
reading
.
This
is
the
location
of
short
to



4
.
lf
voltage
is
present
at
voltmeter,
there
is
a
short
to

ground
.



ground
.

Visually
inspect
the
wire
harness
at
this
point
for
any
faults
.



5
.
lf
voltage
is
not
present,
work
from
wire
harness
near-

If
no
faults
are
visible,
carefully
slice
open
the
harnesscover



est
to
fuse/relay
panel
and
move
orwiggle
wireswhile

or
the
wire
insulation
for
further
inspection
.
Repair
any
faults



observing
meter
.
Continue
to
move
down
harness
until
found
.



meter
displays
a
reading
.
This
is
the
location
of
short
to

ground
.

6
.
Visually
inspect
wire
harness
atthis
point
for
any
faults
.

lf
no
faults
are
visible,
carefully
slice
open
harness
cov-
erorwire
insulation
for
further
inspection
.
Repair
any

faults
found
.

Fig
.
19
.
M44
engine
coolant
temperature
(ECT)
sensor
(arrow)
.



Fig
.
22
.
Headlight
ground
at
left
frontof
engine
compartment
(arrow)
.

0012704

Fig
.
20
.
M52
engine
coolant
temperature
(ECT)
sensor
(A)
is
located
beneath
top
enginecover
(B)
and
crankcase
vent
hose
(C)
.

uu12700

Fig
.
21
.
M52
throttle
position
sensor
(A),
idle
speed
control
valve
(B),
and
secondary
air
pump
(C)
.

ELECTRICAL
COMPONENT
LOCATIONS



610-7

00119s4



0013131

uvijijo
Fig
.
23
.
Mainground
at
right
strut
tower
(A)
.
B
is
negative
jumper
con-
nection
.

COMPONENT
LOCA
TIONS

Tablea
.
E36
Component
Locations

Component



Model
Year



Location



Refer
to
Engine
Compartment
Light
Switch



1993-1996



Over
right
headlight
assembly



Fig
.
7
.

Engine
Control
Module
(ECM)



1992-1998



Right
rear
enginecompartment,
behind
bulkhead
panel



Fig
.
7
.

Engine
Control
Module
(System)



1992-1998



I
Power
distribution
box



Fig
.
2
.
Relay
Engine
Coolant
Leve¡
Sensor



1
1992-1998



1
Left
front
of
enginecompartment,
radiator
coolant
reservoir

Engine
Coolant
Temperature



1992-1998



I
Left
front
of
engine
under
intake
manifold



I



Fig
.
19
.
Sensor



Fig
.
20
.

Evaporative
Emission
Valve



1992-1998



Left
side
strut
Power
area

Evaporator
Temperature
Sensor



1992-1998



Left
side
of
heater
box

EWS
II
Control
Module



1/1995
-
1998



Behind
glove
compartment



Fig
.
8
.
Fig
.
9
.

EWS
II
Ring
Antenna



1
1/1995
-
1998
1
At
ignition
cylinder

EWS
II
Transmitter
Module



1/1995
-
1998



Right
side
of
steering
column
in
auxiliaryrelay
panel



Fig
.
3
.

Exhaust
Gas
Flap
Valve



1996-1998



Left
rear
muffler
area

Flasher
Relay



1992-1998



Power
distribution
box



Fig
.
2
.

Foglight
Relay



1



1992-1998



1
Power
distribution
box



1



Fig
.
2
.

Fresh
Air
FlapActuator



1



1992



1
Right
side
of
heater
box

Fresh
Air
FlapActuator



1
1993-1995



1
Below
right
side
heater
box

Fresh
Air
FlapActuator



1
1996-1998



Below
left
side
heater
box

Fuel
Injectors



1992
-
1998



Top
left
side
of
engine

Fuel
Leve¡
Sensor,
Left



1
1992-1998



/
Under
left
side
of
rear
seat
infuel
tank

Fuel
Leve¡
Sensor,
Right



1



1992-1998



1
Under
right
side
of
rear
seat
in
fuel
tank



1



Fig
.
28
.

Fuel
Pump



1



1992-1998



1



Under
right
side
of
rear
seat
in
fuel
tank



1



Fig
.
28
.

Fuel
Pump
Relay



1



1992-1998



1
Power
distribution
box



1



Fig
.
2
.

Fuel
Pump/Start
Identification
Relay



1994
-
1996



Power
distribution
box

Fuel
Tank
Pressure
Sensor



1
1997-1998



1
Right
rear
wheel
well
behind
trim
liner

ELECTRICAL
COMPONENT
LOCATIONS



610-13

Fuse
andRelay



x(Power



11992-1998



I
Left
side
of
engine
compartment



I



Fig
.
2
.
Distribution
Box



Fig
.
7
Fig
.
10
.

Gas
Filler
LockMotor



1992-1998



Right
side
of
luggage
compartment

Gear
Position/Neutral
Safety
Switch



1992-1998



Next
to
gear
shift
lever
in
center
console



Fig
.
29
.
(Automatic
Transmission
Range
Switch)

Glove
Compartment
Lock
Motor



1994-1998



Behind
glove
compartment

Grounds

G
100



1995-1998



Front
of
left
front
fender
(headlights)



Fig
.
22
.

G
101



1992-1998



Front
of
right
front
fender

Continued

COMPONENT
LOCATIONS

GENERAL
.........
.
.......
.
.
.
.
.
.
.
.
.
..
650-1



Rear
speaker,
removing
and
installing
.
.
.
.
.
.650-5

Door
panel
speaker,

AUDIO
SYSTEM
............
.
.
.
.
.
.
.
.
.
..
650-1



removing
and
installing
.
.
.
.
.....
.
.
.
.
.
.
.
.650-5

Radio
connector
..
.
.
.
.
.
.
.
.
.
.......
.
.
.
.
.
.
650-6

RADIO
AND
SPEAKER
SERVICE
.
.
.
.
.
..
650-2

Radio,
removingand
installing
.
.
.
.
.
.
...
.
..
650-2

Left
footwell
speaker,

removing
and
installing
.
....
.
.
.
.....
.
.
.
650-3

Right
footwell
speaker,

removing
and
installing
.
....
.
.
.
.....
.
..
650-4

GENERAL



AUDIO
SYSTEM

Thissection
coversthe
BMW
factory-installed
sound
sys-



The
BMW
E36
is
equipped
with
a
three
band
radio/cassette

tem,
including
radio
and
speaker
removal,
radio
connectors



player
unit
mounted
in
the
middle
of
thecenter
console
.
In
ad

and
terminal
designations
.



dítion
to
AM
and
FM
bands,
the
radio
will
receive
broadcasts
from
theNational
Weather
Service
.

The
antenna
is
incorporated
into
the
rear
window
defogger
.

650
Radio

Fig
.
1
.



Radio
amplifier
(premiumpackage)
in
luggage
compartment
behind
left
panel
.

RADIO
650-1

TABLE

a
.
Radio
Connector
Terminal
Designation
...
.
......
650-6

The
cassette
deck
is
equipped
with
the
Do1byTM
C
noise
re-
ductionsystem,
for
improved
tape
performance
with
reduced

background
tape
noise
.

A
6-speaker
audio
system
was
standard
in
the
early
years

ofthe
model
line
.
Many
additional
features
have
been
in-
stalled
as
optional
or
standard
equipment
duringthevehicle
production
run
.

"
A
200-watt
power
amplifier
with
custom-contoured

equalization
and
ten
speaker
output
.
See
Fig
.
1
.

"
A
multi-disc
compact
disc
changer,
for
which
the
vehicle

and
the
radio
are
prewired
.
See
Fig
.
2
.

Fig
.
2
.



Optional
multi-disc
compact
disc
changerand
disc
cartridge
.

AUDIO
SYSTEM

650-
6
RADIO

Radio
Connector



Tablea
.
Radio
Connector
Terminal
Designation

Table
a
lists
radio
connector
terminal
designations
.
The
pin

numbers
are
identified
in
Fig
.
15
.

20103040
50

60
90
7
0
0
80
110120130140150160
170

Fig
.
15
.
Radio
connector
.
See
Tablea
.

RADIO
AND
SPEAKER
SERVICE

Terminals
1-17

C1)
Connector

0011850

Connector
SignalTerminal

1



1
Speaker,
left
front
+
2



1



Speaker,
right
front
+
3



1
Speaker,
left
rear
+

4



1
Telephone
mute
feature
(where
applicable)

5



1
Positive
(terminal
R)

6



1
Frontspeaker,
left

7



1
I-bus
connection
(diagnostics)

8



Speaker,
left
front

9



1
Constant
positive,
Terminal
30

10



Speedometer
signal
for
speed-sensitive
volume
control
(where
applicable)

11



1



Speaker,
rightfront

12



1
Speaker,
left
rear

13



1
Illumination
(terminal
58G)

14



Speaker,
right
rear

15



1
Ground
(terminal
31)

16



Automatic
antenna
or
window
antenna
amplifier
or
premiumsound
system
amplifier

17



Notassigned

!'~_T-

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