key battery BMW 318i 1997 E36 Owner's Manual

002262



In
this
system,
three
microswitches
are
operated
via
the
door
lock
cylinder
at
each
front
door
.
Turning
the
key
approximately
Fig
.
17
.
Pufl
off
luggage
compartment
lock
actuating
rod
in
the
direc-



45°
(position
1)
operates
the
door
locking
microswitch
.
Tuming
tionof
arrow
.



the
key
approximately
90°
(position2)
actuates
the
double
locking
microswitch
.
Tuming
the
key
approximately
45°
in
the
opposite
di-
rection
through
position
0
actuates
the
unlocking
microswitch
and
deactivates
the
alarm
system
(position3)
.
See
Fig
.
19
.

Fig
.
18
.
Luggage
compartment
actuatorwire
connectors
and
attach-
ing
screws
(arrows)
.

LOCKING
SYSTEM
AND

ELECTRONIC
IMMOBILIZATION

The
central
locking
system
uses
electrical
lock
actuators
at

each
door
and
at
the
trunk
lid
.
The
locking
system
can
be
ac-

tuated
by
either
front
door
lock
or
by
the
luggage
compartment

lock
.
Onsome
1994
and
later
cars,
an
additional
remote
con-

trol
keypadcan
also
be
used
to
activate
the
lock
and
anti-theft

systems
.

When
the
key
is
tuned
to
the
lock
position,
a
micro-switch

signals
a
central
control
module
to
lock
all
doors,
luggage

compartment,
gas
tank
flap
and,
in
later
convertibles,
the

glove
box
lid
.
Where
applicable,
this
also
arms
the
anti-theft

system
.

CENTRAL
LOCKING
AND
ANTI-THEFT



515-7

NOTE-

The
central
locking
system
responds
to
accidents
vía
animpact
(inertia)
switch
.
When
this
function
ís
activat-
ed,
the
doors
are
automatically
unlocked
and
the
haz-
ard
warning
lights
and
interiorlights
are
turned
on
.
The
impact
switches
are
mounted
in
the
left
and
right
foot-
wells
behind
the
speaker
grilles
.

Central
Locking
System
(ZVM)

Different
versions
of
the
central
locking
control
havebeen
used
in
the
E36
cars
.
In
early
production
cars
(model
years
1992
and
1993),
the
locking
system
is
controlled
through
the
central
locking
module
.
This
system
is
referred
to
as
ZVM
.

Fig
.
19
.
ZVM
door
lock
cylinderpositíons
.

CAUTION-

Do
not
engage
double
locking
position
with
pas-
sengers
in
the
car
unless
the
master
key
isavail-
able
.
The
door
cannotbe
opened
from
outside
orinside
without
the
master
key
.

NOTE-

In
case
of
a
discharged
battery,
the
car
can
still
be
locked
orunlocked
using
the
key
.

0011762

LOCKING
SYSTEM
AND
ELECTRONIC
IMMOBILIZATION

600
Electrical
System-General

GENERAL
.
...........
.
.
.
.
.
.
.
.
.
...
.
...
600-1

Voltage
and
Polarity
........
.
.
.
.
.
.
.
.....
600-1

Ming,
Fuses
and
Relays
............
.
.
.
.
600-1

Electrical
System
Safety
Precautions
...
.
.
.
.
600-1

Electrical
Test
Equipment
.....
.
.
.
....
.
.
.
.
600-2

WIRING
DIAGRAMS
..
.
.
.
.
.
.
.
.
.
........
600-2

Ming
Codes
and
Abbreviations
..
.
...
.
....
600-2

ELECTRICAL
TROUBLESHOOTING
..
.
..
600-3

Voltage
and
Voltage
Drops
..........
.
.
.
.
.
600-4

GENERAL



Electrical
System
Safety
Precautions

A
brief
description
of
the
principal
parts
of
the
electrical
sys-
tem
is
presented
here
.
Also
covered
here
are
basic
electrical
system
troubleshooting
tips
.

Voltage
and
Polarity

The
vehicle
electrical
system
is
a
12-volt
direct
current
(DC)
negative-ground
system
.
A
voltage
regulator
controls
system
voltage
at
approximately
the
12-volt
rating
of
the
battery
.
Al¡
circuits
are
grounded
by
direct
or
indirect
connection
to
the

negative
(-)
terminal
of
the
battery
.
A
number
of
ground
con-

nections
throughout
the
car
connect
the
wiring
harness
to

chassis
ground
.
These
circuits
are
completedby
the
battery

cable
or
ground
strap
between
the
body
and
the
battery
nega-

tive
(-)
terminal
.

Wiring,
Fuses
and
Relays

Nearly
all
parts
of
the
wiring
harnessconnect
to
compo-

nents
of
the
electrical
system
with
keyed,
push-on
connectors

that
lock
into
place
.
Notable
exceptions
arethe
heavy
battery

cables
and
the
starter
wiring
.
The
wiring
is
color-coded
for
cir-

cuitidentification
.

With
theexception
of
the
battery
charging
system,
most

electrical
power
is
routed
from
the
ignition
switch
or
the
bat-
tery
through
the
main
fuse/relay
panel,
located
in
¡he
left
rear

comer
of
the
engine
compartment
.
Fuses
are
color
coded
to

indicate
current
capacities
.

The
relays
and
control
units/modules
are
mounted
in
vari-

ous
places
throughout
the
vehicle
.
See610
Electrical
Com-

ponent
Locations
.

ELECTRICAL
SYSTEM-GENERAL
600-1

Voltage,
measuring
.
.
.
................
.
.
600-4

Voltage
drop,
testing
.
.
.....
.
.....
.
......
600-4

Continuity,
checking
..
.
...
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
600-5
Short
Circuits
.
.
.
.
.
.
.
.
.....
.
...
.
.
.
.
.
.
.
.
.
600-5

Short
circuit,
testing
with
ohmmete'r
.
.
.
.
.
.
.
.
.
600-6

Short
circuit,
testing
with
voitmeter
.
.
.
.
.
.
.
.
.
600-6

TABLES
a
.
Terminal
and
Circuit
Numbers
..............
..
.600-3
Please
read
the
following
warnings
and
cautions
before
do-
ing
any
work
on
your
electrical
system
.

WARNING
-

"
The
cars
covered
by
this
manual
are
equipped
with
aSupplemental
Restraint
System
(SRS)
that
automatically
deploys
one
or
more
airbags
.
Each
airbag
unit
houses
an
explosive
powerful
charge
.
Any
work
involving
the
SRS
system
should
only
be
performed
byan
authorized
BMW
dealer
.
Making
repairs
without
the
proper
knowledge
and
special
test
equipment
may
cause
serious
per-
sonal
injury
.
See
721
Airbag
System
(SRS)
.

"
The
ignition
system
of
the
car
operates
at
lethal
voltages
.
People
with
pacemakers
or
weak
hearts
should
not
expose
themselves
to
the
ignition
sys-
tem
.
Extra
caution
mustbe
taken
when
working
on
the
ignition
system
or
when
servicing
theen-
gine
while
it
is
runningor
the
key
is
on
.
See
120
Ignition
System
for
additional
ignition
system
warnings
and
cautions
.

"
Before
operating
the
starter
without
starting
the
engine
(as
when
making
a
compressfon
test),
dis-
able
the
ignition
system
as
described
in
120
Igni-
tion
System
.

"
Keep
hands,
clothing
and
other
objects
clear
of
the
electric
radiator
coollng
fan
when
working
on
a
warm
engine
.
The
fan
may
start
at
any
tíme,
even
when
the
ignition
is
switched
off
.

GENERAL

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
.

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
.