open gas tank BMW 318i 1997 E36 Workshop Manual

ignition

Table
b
.
Engine
Management
Systems



engine
has
high
mileage
.

Engine



1
System

4-cylinder
engines
M42
(1992-1995)



Bosch
DME
Ml
.7
M44
(1996-1998)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
engines
M50
(1992)



Bosch
DME
M3
.1
M50
VANOS
(1993-1995)



Bosch
DME
M3
.3
.1
M52
(1996-1998)



Siemens
MS41
.1
(OBD
II)
S50US
(1995)



Bosch
DME
M3
.3
.1
S52US
(1996-1998)



Siemens
MS41
.1
(OBD
II)

Both
the
4-cylinder
and
6-cylinder
engines
use
a
distributor-

less
ignition
system
with
individual
ignition
coils
for
each
cylin-

der
.

FuelDelivery

Pressurized
fuel
from
the
in-tank
fuel
pump
is
injected
via

solenoid-type
fuel
injectors
.
The
ECM
controls
the
opening

and
closing
of
the
injectors
by
switchingthe
ground
side
of

each
injector
circuit
.
The
exact
amount
of
fuel
injected
is
de-

termined
by
the
amount
of
timethe
injectors
are
open
.

Cooling
System

Whenever
the
engine
is
running,
acoolant
pump
circulates

coolant
through
the
engine
and,
if
either
heater
control
valves

are
open,
through
the
heater
core
in
the
passenger
compart-

ment
.
The
coolant
absorbs
excess
heat
and
carries
it
to
the
ra-

diator
where
it
is
transferred
into
the
passing
airstream
.
A

thermostat
controls
the
flow
of
coolant
through
the
radiator

based
on
engine
temperature
.

Lubrication
System

The
lubrication
system
is
pressurized
whenever
theengine

is
running
.
The
oil
pump
draws
oil
through
a
pickup
in
the
bot-

tom
of
the
oil
pan,thenforces
it
through
a
replaceable
oil
filter

and
finto
the
engine
oíi
passages
.

On
4-cylinder
engines,
the
oil
pump
is
mounted
to
the
front

engine
cover
.
On
6-cylinder
engines,thechain-driven
oil

pump
is
bolted
to
the
bottom
of
the
cylinder
block
.

A
pressure
relief
valve
limits
the
maximum
system
pres-

sure
.
A
bypass
valve
prevents
the
oil
filter
from
bursting
and

insures
engine
lubrication
should
the
filter
become
plugged
.

See
119
Lubrication
System
for
additional
information
.

ENGINE-GENERAL
100-
5

Various
versions
of
DME
systems
are
usedon
thecars
cov-



MECHANICAL
TROUBLESHOOTING
ered
by
this
manual
.
See
Table
b
.
Each
system
is
highly
adaptive
to
compensate
for
things
suchasengine
wear
and



When
troubleshooting
an
engine
that
fails
to
start
or
runs
vacuum
leaks
.



poorly,
first
check
its
mechanical
condition-particularly
if
the

Warnings
and
Cautions

For
personal
safety,
as
well
asthe
protection
of
sensitive
electronic
components,
the
following
warnings
and
cautions
must
be
adhered
to
during
all
troubleshooting,
maintenance,
and
repairwork
.

WARNING
-

"
The
ignition
system
produces
high
voltages
that
can
be
fatal
.
Avoid
contact
with
exposed
termi-
nals
anduse
extreme
caution
when
working
on
a
car
with
the
ignition
switched
on
or
the
engine
running
.

"
Do
not
touch
or
disconnect
any
high
voltage
ca-
bles
from
the
coil,
distributor,
orspark
plugs
while
the
engine
is
running
or
being
cranked
by
the
starter

"
Connect
and
disconnect
the
engine
manage-
ment
system
wiring
and
test
equipment
leads
only
when
the
ignition
is
switched
off
.

"
Gasoline
is
highly
flammable
and
its
vapors
are
explosive
.
Do
not
smoke
or
work
on
a
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extínguisher
available
in
case
of
an
emergency
.

"
Disconnecting
the
battery
may
erase
fault
code(s)
stored
in
control
module
memory
.
Using
special
BMW
diagnosnnc
equipment,
check
for
fault
codes
prior
to
disconnecting
the
battery
cables
.
If
the
Check
Engine
lightis
illuminated,
see
On-

Board
Diagnostics
(OBD)
forfault
code
infor-
mation
.
If
any
other
system
faults
havebeen
de-tected
(indicated
byan
illuminated
warning
light),
see
an
authorized
BMW
dealer
.

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-
tery
disconnection
cautions
gíven
at
the
front
of
this
manual
on
page
viii
.

"
Do
notconnect
any
test
equipment
that
delivers
a
12-volt
power
supply
to
terminal15
(+)
of
the
ignition
coil
.
The
current
flow
may
damage
the

ECM
.
In
general,
connect
test
equipment
only
as
specified
by
BMW,
this
manual,
or
the
equip-
ment
maker
.

"
Do
not
disconnect
the
battery
with
the
engine
running
.
Do
notrunthe
engine
with
any
of
the
sparkplug
wires
disconnected
.

MECHANICAL
TROUBLESHOOTING

130-
1
0



FUEL
INJECTION

Relleving
fuel
pressure
and
connecting

fuel
pressure
gauge

WARNING
-

"
Gasoline
is
highly
flammable
and
its
vaporsare
explosive
.
Do
not
smoke
orwork
on
acarnear
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extinguisher
available
in
case
of
an
emergency
.

"
When
working
onanopen
fuel
system,
wear
suit-
able
hand
protection
.
Prolonged
contact
with
fuel
can
cause
illnesses
and
skin
disorders
.

To
prevent
fuel
from
spraying
on
a
hot
engine,
system
fuel

pressure
should
be
relieved
before
disconnecting
fuel
lines
.

One
method
is
to
tightly
wrap
a
shop
towel
around
a
fuelline
fit-

ting
and
loosenor
disconnect
the
fitting
.

Cleanliness
is
essential
when
working
with
fuelcircuit
com-
ponents
.
Thoroughly
clean
theunionsbefore
disconnecting
fuellines
.

NOTE-

"
OnM44
engines,
a
Schrmder
valve
is
integrated
in
the
fuel
rail
.
Compressed
air
pressure
canbe
applied
at
the
valve
to
force
the
fuel
in
the
system
back
into
the
tank
.
See
Fig
.
11
.

0012503

Fig
.
11
.
Fuel
rail
showing
location
of
Schraeder
valve
fitting
on
M44
engine
(arrow)
.

NOTE-

B~
specifies
a
special
gauge
and
special
connecting
adapters
to
measure
fuel
pressure
.
If
the
special
tools
arenot
available,
a
length
of
fuel
fine
and
a
T-fitting
canbe
installed
to
the
inlet
fuel
fine
and
connected
to
a
fuel
gauge
.
On
some
vehicles,
thisis
not
possible
without
cutting
finto
a
fuel
lino
.
In
these
lnstances,
it
Is
recom-
mended
that
fuel
pressure
be
checked
at
theoutput
sidoof
the
fuel
pump
.
See
160
Fuel
Tankand
Fuel
Pump
.

FUELDELIVERY
TESTS

On
OBD
II
6-cylinder
engines,
the
fuel
lines
use
a
special

locking
fitting
.
Use
BMW
special
tool
16
1
050
to
release
the

fittings
and
connect
the
fuel
gauge
.
See
Fig
.
12
.

0012699

Fig
.
12
.
Fuel
linos
at
rear
of
intake
manifold
on
M52
engine
.
Use
BMW
special
tool
16
1
050
torelease
fittings
.

WARNING
-

"
Gasoline
is
highly
flammable
and
its
vapors
are
explosive
.

"
The
fuel
pressure
gauge
must
be
securely
con-nected
to
prevent
it
from
coming
loose
under
pressure
.

NOTE-

"
The
fuel
pressure
gauge
should
have
arangoof
0
to
5
bar
(0
to
75
psi)
.

"
On
6-cylinder
engine,
thetop
left-sido
engine
cover
will
have
to
be
removed
to
access
the
fuel
rail
.

Residual
fuel
pressure,
testing

For
quick
restarts
and
to
avoid
vapor
lock
when
the
engine
is
hot,
the
fuel
injection
system
is
designed
to
retain
fuel
pres-
sure
after
the
engine
has
been
turned
off
.
Thís
residualpres-
sure
is
primarily
maíntained
by
a
check
valve
at
the
fuel
pump
outiet
and
the
fuel
pressure
regulator
.
The
fuel
pump
check
valve
is
not
serviceable
asan
individual
part
.

1.
Relieve
fuel
pressure
and
connect
a
pressure
gauge
as
described
earlier
.

WARNING
-

Fuel
will
be
discharged
.
Wrap
a
shop
towel
around
the
fuellino
fitting
when
disconnecting
the
fuel
fine
.
Do
not
smoke
or
worknear
heaters
or
other
fire
hazards
.
Keep
an
approved
fire
extinguisher
handy
.

2
.
Operate
fuel
pump
for
approximately
one
minuto
by
by-
passing
fuel
pump
relay
as
described
earlier
.
Observe
fuel
pressure
.

160
Fuel
Tank
and
Fuel
Pump

GENERAL
.
.
.
.
.
.
...........
.
....
.
.
.
.
.
.
160-1



Operating
fuel
pump
for
tests
.
.
.
.
.
.
.......
.160-6

Fuel
Pump
Electrical
Tests
.
.
.
.
.
.
.
...
.
.
.
.
.
160-7

FUEL
TANK
AND
LINES
..
.
.
.
..........
160-2



Fuel
pump
electrical
circuit,
testing.
...
.
.
.
.
.
160-7

Fuel
tank,
draining
..
.
.
.
.
.
.
.
.
.
..........
160-2



Fuel
pump
power
consumption,
testing
.
.
.
.
.
.
160-7

Fuel
tank,
removing
and
installing
.........
160-3



Fuel
Delivery
Tests
....
.
.
.
...
.
.....
.
.
.
..
160-8

Fuel
Tank
Evaporative
Control
System
.....
160-4



Relieving
fuel
pressure
and
connecting

fuel
pressure
gauge
..
.
...........
.
.
.
..
160-8

FUEL
LEVEL
SENDERS
.
.
.
.
.
.......
.
.
.
160-4



System
pressure,
testing
.................
160-9

Fuel
level
senders,
testing
.
.
.
.
.
.......
.
.
.
160-5



Fuel
delivery
volume,
testing
.............
160-10

Fuel
leve¡
sender
and
fuel
pump
(right
side),
emoving
and
installing
.
.
.
.
.
.
160-5



TABLES

Fuel
leve¡
sender
(left
side),



a
.
FuelLeve¡
Sender
Resistances
...........
.
.
..
.160-5

removing
and
installing
.........
.
.
.
.
.
.
.
160-6



b
.
Fuel
Pump
Current
...
.................
..
...
160-8

c
.
Fuel
Pressure
Specifications
..............
.
..
160-10

FUEL
PUMP
.
.
.
................
.
.
.
.
.
.
.
160-6



d
.
Fuel
Pump
Delivery
Specifications
.........
.
..
160-10

Fuel
Pump
Fuse
and
Relay
.
.
.
....
.
.
.
.
.
.
.
160-6

GENERAL

This
repair
group
covers
service
information
specifically
for



The
cautions
and
warnings
on
this
page
should
beob
the
fuel
supply
system
.
Information
on
the
fue¡
injection
sys-



served
when
servicing
the
fuel
system
.
tem
is
covered
in
130
Fuel
Injection
.

NOTE-

Fue¡
filter
replacement
is
covered
in
020
Maintenance
Program
.

WARNING
-

"
The
fuel
system
is
designed
to
retain
pressure
even
when
the
ignition
isoff
.
When
working
with
the
fuel
system,
loosen
the
fuel
lines
slowly
toal-
low
residual
fuel
pressure
to
dissipate
gradually
.
Avoid
spraying
fuel
.

"
Before
beginning
any
work
on
the
fuel
system,
place
a
tire
extinguisher
in
the
vicinity
of
the
work
area
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
tire
hazards
.

"
Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
fines
.

"
Do
not
use
a
work
light
near
any
fuel
.
Fuel
may
spray
onto
the
hot
bulb
causing
a
tire
.

"
Make
sure
the
work
area
is
properly
ventifated
.

FUEL
TANK
AND
FUEL
PUMP



160-1

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viü
.

"
Before
making
any
electrical
tests
with
the
ignition
tumed
on,
disable
the
ignition
system
as
de-
scribed
in
120
Ignition
System
.
Be
sure
the
bat-tery
is
disconnected
when
replacing
components
.

"
To
prevent
damage
to
the
ignition
system
or
the
electronic
fuel
system
components,
including
the
control
unit,
aiways
connect
and
disconnect
wires
and
test
equipment
with
the
ignition
off
.

"
Cleanliness
is
essential
when
working
with
the
fuel
system
.
Thoroughly
clean
the
fuel
fine
unionsbefore
disconnecting
any
of
the
fines
.

"
Use
only
clean
tools
.
Keep
removed
parts
clean
and
sealed
or
covered
with
a
clean,
lint-free
cloth,
especially
if
completion
of
the
repair
is
delayed
.

"
Do
not
move
the
car
while
the
fuel
system
is
open
.

"
Avoid
using
high
pressure
compressed
air
to
blow
out
fines
and
componente
.
High
pressure
can
rupture
infernal
seals
and
gaskets
.

"
Always
replace
seals
and
O-rings
.

GENERAL

160-
8



FUEL
TANK
AND
FUEL
PUMP

UU131
tst5

Fig
.
11
.
Voltage
supply
to
fuel
pump
harness
(black)
connector
being
checked
(arrow)
.

00131ts7

Fig
.
12
.
Test
fuel
pump
for
current
draw
by
attadhing
ammeter
andjumper
wire
as
shown
.

CAUTION-

Do
not
allow
the
test
leads
to
short
to
ground
.

NOTE-

See
600
Electrical
System-General
for
information
on
electricaltests
using
a
digital
multimeter
(DMM)
.

4
.
Run
pump
as
described
in
Operating
fuel
pump
for
tests
.

FUEL
PUMP

5
.
Compare
ammeter
reading
with
specification
listed
in

Table
b
.

Maximum
current



5
.0
amps
consumption

FuelDelivery
Tests

Table
b
.
Fuel
Pump
Current

Checking
fuel
delivery
is
a
fundamental
part
of
trouble-

shooting
and
diagnosing
the
DME
system
.
Fuelpressure
di-

rectly
influences
fuel
delivery
.
An
accurate
fuel
pressure

gauge
will
be
needed
to
make
the
tests
.

There
arethree
significant
fuel
delivery
values
to
bemea-

sured
:

"
System
pressure-created
by
the
fuel
pump
and
main-

tained
by
the
pressure
regulator
.

"
Fuel
delivery
volume-created
by
the
fuel
pump
and
af-

fected
by
restrictions,
suchas
clogged
fuel
filter
.

"
Residual
pressure-the
pressure
maintained
in
the

closed
system
after
the
engine
and
fuel
pump
areshut

off
.

Procedures
for
measuring
the
first
two
quantities
arede-

scribed
here
.

Residual
fuel
pressure
is
checked
using
the
procedurede-

tailed
in
130
Fuel
Injection
.

Relieving
fuel
pressure
and
connecting

fuel
pressure
gauge

WARNING
-

"
Gasoline
is
highly
flammable
and
its
vaporsare
explosive
.
Do
not
smoke
or
work
ona
car
near
heaters
or
other
fire
hazards
when
diagnosing
and
repairing
fuel
system
problems
.
Have
a
fire
extinguisher
available
in
case
of
an
emergency
.

"
When
working
onan
open
fuel
system,
wear
suit-
able
hand
protection
.
Prolonged
contact
with
fuel
can
cause
iflnesses
and
skin
disorders
.

CA
UTION-

Cleanliness
is
essential
when
working
withfuel
circuit
components
.
Thoroughly
clean
the
unionsbefore
disconnecting
fuel
fines

To
prevent
fuel
from
spraying
on
a
hotengine,
system
fuel

pressure
should
be
relieved
before
disconnecting
fuel
lines
.

One
method
is
to
tightly
wrap
a
shop
towel
around
a
fuel
line
fit-
ting
and
loosen
or
disconnect
the
fitting
.

Measuring
fuel
pressure
requires
special
tools
.
Earlier
cars
use
pressure
hose
with
clamps
for
fuel
delivery
.
These
can
be
attached
to
a
fuel
pressure
gauge
below
the
intake
manifold
.

Cooling
System
Pressure
Test



If
the
engine
overheats
and
no
other
cooling
system
testsindicate
trouble,
the
radiator
may
have
some
pluggedpassag-

A
cooling
system
pressure
test
is
used
to
check
for
internal



es
that
are
restricting
coolant
flow
.

leaks
.
Some
of
the
common
sources
ofinternal
leaks
are
a
faulty
cylinder
head
gasket,
a
cracked
cylinder
head,
or
a



Temperature
Gauge
Quick
Check
cracked
cylinder
block
.

The
coolant
temperature
sensor
is
located
on
the
intake
To
doa
cooling
system
pressure
test,
a
special
pressure



manifold
(left)
side
of
the
cylinder
head,
under
the
intake
man-
tester
is
needed
.



ifold
runners
.
See
Fig
.
2
.

WARNING
-

At
normal
operating
temperature
-
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
before
opening
.
Release
the
cap
slowly
to
allow
sale
re-
tease
of
pressure
.

With
the
engine
cold,instan
a
pressure
tester
to
the
expan-

sion
tank
.
Pressurize
thesystem
to
the
specification
listed
be-

low
.
Pressure
should
not
drop
more
than
0
.1
bar
(1
.45
psi)
for

at
leakt
two
minutes
.
If
the
pressure
drops
rapidly
and
there
is
no
sign
of
an
externa¡
leak,
the
cylinder
head
gasket
may
be
faulty
.
Considera
compression
test
as
described
in
100
En-

gine-General
.

The
screw-on
type
expansion
tank
cap
should
also
be
test-

ed
using
a
pressure
tester
and
the
correct
adapter
.

Cooling
System
Test
Pressure

"
Radiator
test
pressure
.........
.
1
.5
bar
(21
.75
psi)

"
Radiator
cap
test
pressure
..
.
........
2
bar
(29
psi)

CA
UTION-

Exceeding
the
speclfied
test
pressure
could
dam-
age
the
radiatoror
other
system
components
.

Carefully
inspect
the
radiator
cap
for
damage
.
Replace
a

faulty
cap
or
a
damaged
cap
gasket
.

Thermostat
Quick
Check



In
later
models,
the
ECT
sensor
and
the
gauge
sender
are
combined
into
one
sender
unit
.
For
wire
colors
refer
to
Table
a
.
To
check
if
the
thermostat
is
opening
and
coolant
is
circulat-

ing
through
the
radiator,
allow
a
cold
engine
to
reach
operat-

ing
temperature
(temperature
gauge
needieapproximately

centered)
.
Shut
off
engine
.
Feel
the
top
radiator
hose
.
If
the

hose
is
hot
to
the
touch,
the
coolant
is
probably
circulating
cor-
rectly
.
If
there
are
any
cool
areas
in
the
hose
or
radiator,
cool-

ant
flow
to
the
radiator
is
probably
restricted
.
Check
for
a
faulty

thermostat
or
aplugged
radiator
.

NOTE-

A
thermostat
that
is
stuck
open
will
cause
the
engine
to
warmup
slowly
and
run
belownormal
temperature
at
highway
speed
.
A
thermostat
that
is
stuck
closed
will
re-

strict
coolant
flow
to
the
radiator
and
cause
overheating
.

RADIATOR
AND
COOLING
SYSTEM



170-
3

U
.¡ig
.v

Fig
.
2
.
Temperature
gauge
sender
on
M44
engine
.
Temperature
gauge
sender
location
is
similar
on
al]
engines
.

In
early
models,
the
engine
coolant
temperature
(ECT)
sen-

sor
for
the
fuel
injection
and
the
coolant
temperature
gauge

sender
are
located
side
by
side
.

Table
a
.
Coolant
Temperature
Sensor
Wire
Colors

Function



Sensor



Terminal



Wire
colors
location
number

Two
sensors
:
Temperature
Rear
1
Brown/violet
gauge
sender



2



Brown/yellow
ECT
sensor



Front



1



Brown/red
2



Brown
or
Brown/black

One
sensor
:
Temperature
Dual
1
Brown/yellow
gauge
sender



sensor



2



Brown/violet
ECT
sensor



3



Brown/red
4
Brown/black
or
Grey/black

TROUBLESHOOTING

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