1997 BMW 328i engine mount

Fig
.1.



Electrical
system
static
current
draw
being
measured
.

To
determine
the
circuit
or
component
causing
the
problem,

remove
one
Puse
at
a
time
until
the
current
drops
to
a
normal
range
.

BATTERY
SERVICE

The
E36
uses
a
six-cell,
12-volt
leadacid
battery
mounted

in
the
luggage
compartment
.
See
Fig
.
2
.

NOTE-

E36
convertible
models
require
a
specialbattery
which
is
designed
for
constant
vibratfon
.
A
battery
not
de-signed
for
this
will
fail
much
earlier
.

Battery
capacity
is
determined
by
the
amount
of
current

needed
tostart
the
vehicle,
and
by
the
amount
of
current
con-
sumed
by
the
electrical
system
.

BMW
batteries
are
rated
by
ampere/hours
(Ah)
and
cold

cranking
amps
(CCA)
rating
.
The
Ah
rating
is
determined
by

the
average
amount
of
current
the
battery
can
deliver
over
time
without
dropping
below
a
specified
voltage
.
The
CCA
is

determined
by
the
battery's
ability
to
deliver
starting
current
at

0°
F
(-18°
C)
without
dropping
below
a
specified
voltage
.

Battery
Testing

noN~A

B9517

Battery
testing
determines
the
state
of
battery
charge
.
On

conventional
or
low-maintenance
batteries
the
most
common

method
of
testing
the
battery
is
that
of
checking
the
specific

gravity
of
the
electrolyte
using
a
hydrometer
.
Before
testing

the
battery,
check
that
the
cables
are
tight
and
free
of
corro-

sion
.
See
Fig
.
2
.

Hydrometer
Testing

The
hydrometer
consists
of
a
glass
cylinder
with
a
freely

moving
float
inside
.
When
electrolyte
is
drawn
into
the
cylin-

der,
the
levelto
which
the
float
sinks
indicates
the
specific

BATTERY,
STARTER,
ALTERNATOR



121-
3

Fig
.
2
.



Battery
in
right
sideof
luggage
compartment
.

gravity
of
the
electrolyte
.
The
more
dense
the
concentration
of
sulfuric
acid
in
the
electrolyte,
the
less
the
float
will
sink,
result-

ing
in
a
higher
reading
and
indicating
a
higher
state
of
charge)
.

NOTE-

Electrolyte
temperature
affects
hydrometer
reading
.
Check
the
electrolyte
temperaturewith
a
thermometer
.
Add
0
.004
to
the
hydrometer
reading
for
every
10°F
(6°C)
that
the
electrolyte
is
above
80°F
(27°C)
.
Sub-
tract
0
.004
from
the
reading
for
every
10°F
(6°C)
that
the
electrolyte
is
below
80°F
(27°C)
.

Before
checking
the
specificgravity
of
a
battery,
load
the
battery
with
15
amperes
for
one
minute
.
lf
the
battery
is
in-

stalled
in
the
vehicle,
this
can
be
done
by
turning
on
the
head-

lights
without
the
engine
running
.
Table
b
lists
the
percentage

of
charge
based
on
specific
gravity
values
.

Table
b
.
Specific
Gravity
of
Battery
Electrolyteat

80
°
F
(27°C)

Specific
gravity



1



Stateof
charge

1
.265



Fully
charged
1
.225



75%
charged
1
.190



50%
charged
1
.155



25%
charged
1
.120



Fully
discharged

The
battery
isin
satisfactory
condition
if
theaverage
specif-

ic
gravity
of
the
six
cells
is
at
least
1
.225
.
If
the
specific
gravity

is
above
this
leve¡,
butthe
battery
lacks
power
for
starting,
de-

termine
the
battery's
senrice
condition
with
a
load
voltage
test,

as
described
below
.
If
the
average
specific
gravity
of
the
six

cells
is
below
1
.225,
remove
the
battery
from
the
luggage

compartment
and
recharge
.
If,
after
recharging,
the
specific
gravity
varies
by
more
than
0
.005
between
any
two
celis,
re-

place
the
battery
.

CHARGING
SYSTEM
TROUBLESHOOTING

2
.
Remove
cooling
duct
or
terminal
cover
from
rear
of
al-



2
.
Remove
air
cleaner
upper
section
with
mass
air
flow
ternator
.



sensor
.

3
.
Check
for
battery
voltage
between
ground
and
terminal



3
.
Remove
terminal
cover
from
rear
of
alternator
.
Discon
B+
at
back
of
alternator
.
Then
turn
ignition
on
and



nect
wiring
.
check
for
battery
voltage
between
terminal
D+
and
ground
.
See
Fig
.
3
.
lf
voltage
is
not
present
at
either



4
.
Remove
drive
belt
from
alternator
pulley
.
See
020
point,
check
wiring
for
faults
.



Maintenance
program
.

001
¡987
Fig
.
3
.



Terminal
B+
is
supplied
battery
voltage
directly
from
the
bat-
tery
.
Terminal
D+
is
supplied
battery
voltage
via
the
charge
warning
bulb
when
thekey
is
on
or
the
engine
is
running
.

4
.
lf
no
faults
are
foundup
to
thispoint,test
alternator
out-

put
using
a
load
tester
.

5
.
If
a
load
tester
is
not
available,
a
crude
output
test
can
be
done
by
running
engine
at
about
2000
rpmand
turn-
ing
on
electrical
loads
(fans,
lights
and
rear
window
de-
froster,
wipers)
.
With
al¡
accessories
on,
battery
voltage
should
be
above
12
.0
VDC
.

A
replacement
alternator
should
have
the
same
rating
as
the
original
.
Alternator
manufacturer
and
ampere
rating
are
normally
marked
on
the
alternator
housing
.
1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
vi¡¡
.

BATTERY,
STARTER,
ALTERNATOR



121-
5

6
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-
ternator
.
See
Fig
.
4
.

NOTE
-

If
reusing
drive
belt,
mark
direction
of
rotation
on
belt
before
removing
.

5
.
On
M44
engine
with
hydraulic
belt
tensioner
:
Remove
tensioner
idler
pulley
(upper
roller)
from
alternator

bracket
.

Fig
.
4
.



Alternator
mounting
bolts
(arrows)
.

O



u
J
S
v~~

U

I



1
i
n
-12
.22

Alternator,
removing
and
installing



7
.
Installation
is
reverse
of
removal
.
Install
drive
belt
as

(4-cylinder
engine)



described
in
020
Maintenance
Program
.

Tightening
Torques

"
D+
vire
to
alternator
(M6
nut)
.
...
.
.
.
7
Nm
(53
in-lb)

"
B+
wire
to
alternator
(M8
nut)
..
.
.
.
.
.
13
Nm
(10
ft-Ib)

"
Pulley
to
alternator
(M16
nut)
...
..
..
60
Nm
(44
ft-Ib)

ALTERNATOR
SERVICE

121-
6



BATTERY
STARTER,
ALTERNATOR

Alternator,
removing
and
installing

(6-cylinder
engine)

A
replacement
alternator
should
have
the
same
rating
as

the
original
.
Alternator
manufacturer
and
ampere
rating
are

normally
marked
on
the
alternator
housing
.

1
.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

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

2
.
Remove
alternator
cooling
duct
and
air
filter
housing

assembly
from
car
.
Disconnect
wiring
from
rear
of
alter-

nator
.

3
.
Remove
radiator
cooling
fan
and
fan
shroud
.
See
170

Radiator
and
Cooling
System
.

4
.
Remove
alternator
drive
belt
from
alternator
pulley
.
On

engines
with
hydraulic
belt
tensioner,
remove
tensioner

idler
pulley
(upper
roller)
from
alternator
bracket
.
See

Fig
.
5
.

ALTERNATOR
SERVICE

Fig
.
5
.



Pry
off
cover
from
tensioner
and
then
lever
tensioner
clock-
wise
to
release
belt
tension
.
Remove
upper
roller
(A)
once
belt
ís
removed
.

NOTE-

If
reusing
drive
belt,
mark
direction
of
rotation
on
belt

before
removing
.

5
.
Remove
upper
and
lower
mounting
bolts
and
lift
out
al-

ternator
.

6
.
Installation
is
reverse
of
removal
.
Note
locating
notches
on
tensioner
idler
pulley
(upper
roller)
alternator
brack-

et
when
installing
pulley
.

Tightening
Torques

"
D+
wire
to
alternator
(M6
nut)
.......
7
Nm
(53
in-lb)

"
B+
wireto
alternator
(M8
nut)
.......
13
Nm
(10
ft-Ib)

"
Pulley
to
alternator
(M16
nut)
.......
60
Nm
(44
ft-Ib)

Voltage
regulator,
removing
and
installing

1
.
Disconnect
negative
(-)
cable
from
battery
.

NOTE-



2
.
Remove
alternator
as
described
earlier
.

The
radiator
cooling
fan
nut
(32
mm
wrench)has
left-
hand
threads
.



3
.
Remove
cooling
duct
from
rear
of
alternator
.
See
Fig
.
6
.

Alternator

.
.g-



p~
J

-..
.

Fig
.
6
.



Alternator
assemblyand
related
parts
.

Cooling
duct

0012524

4
.
Remove
voltage
regulator
mounting
screws
and
re-

move
regulator
from
alternator
.

5
.
Installation
is
reverse
of
removal
.
Clean
brush
contact

surfaces
in
alternator
and
check
brush
length
asde-

scribed
later
.

121-1
O



BATTERY,
STARTER,
ALTERNATOR

9
.
Remove
starter
from
above
.

10
.
Check
starter
pinion
gear
and
flywheel
teeth
for
dam-
age
.

11
.
Installation
is
reverse
of
removal
.

Tightening
Torques

"
tntakemanifold
to
cylinder
head

M7
nut
...
.
................
...
.
15
Nm
(11
ft-Ib)

M8
nut/bolt
.............
.
.
..
...
22
Nm
(16
ft-Ib)

"
Starter
to
engine
block
(M10
bolt)
...
50
Nm
(37
ft-Ib)

"
Support
bracket
to
starter
(M5
nut)
...
5
Nm
(44
in-lb)

"
Support
bracket

to
engine
block
(M10
bolt)
.
.
..
..
...
47
Nm
(35
ft-Ib)

"
Wire
toterminal
50
(M6
nut)
.
..
.....
6
Nm
(53
in-lb)

"
Wire
toterminal
30
(M8
nut)
...
.....
12
Nm
(9
ft-Ib)

Solenoid
switch,
removing
and
installing

1
.
Remove
starter
as
described
above
.
Tightening
Torque

2
.
Remove
cover
from
solenoid
switch
.



"
Field
winding
strap
to
starter
(M8)
...
.
12
Nm
(9
ft-Ib)

3
.
Disconnect
fieid
winding
strap
between
starter
motor

and
solenoid
switch
.

NOTE-

The
condition
of
the
field
winding
strap
is
critical
.
If
it
is
damaged,
bumed
or
partially
melted
through,
a
new
or

rebuilt
starter
motor
is
needed
.

4
.
Remove
solenoidswitch
mounting
screws,
and
sepa-

,
rate
solenoid
from
starter
.
See
Fig
.
12
.

CAUTION-

When
installing
fieid
winding
strap
to
starter,
posi-

tion
it
so
that
it
does
not
contact
the
starter
body
.

STARTER
SERVICE

131~184

Fig
.
12
.
Starter
solenoid
mounting
screws
(arrows)
are
tight
.
Use
en
impact
screwdriver
to
loosen
the
screws
.

5
.
Installation
is
reverse
of
removal
.
Lubricate
solenoid
pistos
with
light
grease
.

GENERAL
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.........
130-2



Intake
air
temperature
(IAT)
sensor,

Principles
of
Operatinn
.
.
.
.
.
.
.
.
.
.........
130-2



testing
and
replacing
...
.
...
.
.
.
.......
.
130-19

Basic
Engine
Settings
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
:
.
130-3



Throttle
position
sensor
(TPS),

DISA
(Dual
Resonance
Intake
System)
.
.
.
.
.
130-3



testing
and
replacing
...
.
...
.
.
.
.
.
...
.
.
.130-19

On-Board
Diagnostics
(OBD)



Idle
speed
control
valve,
testing
.
.
.
.
.
.
.
.
.
.
130-20

and
Fault
Diagnosis
.
.
....
.
......
.
.
.
...
130-4



Idle
speed
control
valve,
replacing
.
.
.
.
.
.
..
130-21

SecondaryAir
Injection
.
.
.....
.
.........
.
130-5



BOSCH
DME
M5
.2
COMPONENT
Warnings
and
Cautions
.
.
...
.
.
.
.........
.
130-6



REPLACEMENT
.....
.
......
.
....
.
.
.
..
130-21

ELECTRICAL
CHECKSAND



Mass
air
flow
sensor,
replacing
.
.
....
.
....
130-22

COMPONENT
TESTING
.
.
.
.
.
.
.
.
...
.
.
.
.
.
130-7



Engine
coolant
temperature
(ECT)

Main



sensor,
replacing
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130-22
rela
y
testing



130
-7
,...
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.



Intake
air
temperature
(IAT)
sensor,
Fuel
pump
relay,
testing
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
130-7



rep
lacin
.
.
.
.
.
.
.
.
.
.
.g



.
.
.
.
.
.
.
...
.
.
.
..
.130-22
Oxygen
sensor,
testing
(Boschsystems
only)
130-8



Throttle
poson
sensor
(TPS)
replacing



13022
,



..
.-

FUEL
DELIVERY
TESTS
...
.
....
.
.
.
...
.
130-9



Idle
speed
control
valve,
replacing
...
.
....
.130-23

Operating
fuel
pump
for
tests
.
.
.......
.
...
130-9



SIEMENS
MS
41
.1
COMPONENT
Relieving
fuel
pressure
and



REPLACEMENT
.
...
.
.
.
.
.
.......
.
....
.130-23
connecting
fuel
pressure
gauge
......
.
..
130-10

Residual
fuel
pressure,
testing
.
.....
.
.
.
.
.
130-10



Mass
air
flow
sensor,
replacing
.
.......
.
.
.130-25

Fuel
pressure
regulator
response



Engine
coolant
temperature
(ECT)

to
engine
load,
testing
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130-11



sensor,
replacing
.....
.
.
.
.
.
.........
.130-25

Fuel
rail
and
injectors,
checking
...
.
.
.
.
.
.
.
130-11



Intake
air
temperature
(IAT)
sensor,
replacing
.
.
.
.
.
.....
.
.
.
.
.
.
.
.......
.
.
.130-25
Fuel
rail
and
injectors,
replacing



..
.
.
.
.
.
.
.
130-12



Throttleposition
sensor
(TPS),
replacing
.
.
.
130-26
Fuel
PressureRegulator
.........
.
.
.
.
.
.
.
130-13



Idle
s
eed
control
valve,
re
lacin



130-26
Fuel
pressure
regulatorreplacing



p



p



g
.'''...
.
'
,

(fuel
rail
mount)
...
.
.
.
.
.
.............
130-13



ECM
PIN
ASSIGNMENTS
.............
.
.
130-26
Fuel
pressure
regulator,
replacing



Engine
control
module
(ECM),
accessing
...
130-26
(undercar
mount)
.
.
.
.
.
.
.
.
.........
.
.
130-14

BOSCH
DME
M1
.7
COMPONENT

TESTS
AND
REPAIRS
.
.
.
.
.
...
.
.
.
.
.
.
.
.
130-14

Air
flow
sensor,
testing
and
replacing
.
.
.
.
.
.
130-14

Engine
coolant
temperature
(ECT)

sensor,
testing
and
replacing
...
.
.
.
.
.
.
.
.
130-15

Throttle
position
sensor
(TPS),

testing
and
replacing
.
..........
.
.....
130-16

Idle
speed
control
valve,
testing
and
replacing
.
.
.
.
.
............
130-16

BOSCH
DME
M3
.1
AND
M33
.1

COMPONENT
TESTS
AND
REPAIRS
.
.
.
130-17

Mass
Air
Flow
Sensor
.
.
.
.
.
.
.
.
.....
.
.
.
.
.130-17

Mass
air
flow
sensor
(hotwire),testing
and
replacing
.
.
.
.
.
.....
.
.
.
.
.
.
.
130-17

Mass
air
flow
sensor
(hot
film),

testíng
and
replacing
.
.
.
.....
.
.
.
.
.
.
.
.
.
130-18
Engine
coolant
temperature
(ECT)

sensor,
testing
and
replacing
..
.
.
.
.
.
...
.
130-18

130
Fuel
i
n
jection

FUEL
INJECTION



130-1

TABLES
a
.
Engine
Management
System
Variants
.........
.130-2
b
.
Mass
Air
Flow
Sensor
Variants
..
.
..
..........
.130-2
c
.
Fuel
Pressure
Specifications
..
.
.
...
..........
130-11
d
.
Engine
Coolant
Temperature
Sensor
or
Intake
Air
Temperature
Sensor
Test
Values
(DME
1
.7)
...
.
130-15
e
.
ThrottlePosition
Sensor
Tests
(DME
1
.7)
......
.130-16
f
.



Engine
Coolant
Temperature
Sensor
or
Intake
Air

Temperature
Sensor
Test
Values
(DME
3
.1/3
.3
.1)130-19
g
.
Throttle
Position
Sensor
Tests
(DME
3
.1/3.3
.1)
.
.130-20
h
.
ECM
Pin
Assignment-Bosch
DME
M1
.7
....
.
..
.130-28
i.



ECM
Pin
Assignment-Bosch
DME
M3
.1
.......
.130-30
j
.



ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
.....
.130-32
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
.......
.
130-34
I.



ECM
Pin
Assignment-Siemens
DME
MS
41
.1
..
.
130-36

130-2



FUEL
INJECTION

GENERAL

This
repair
group
covers
fuel
injection
system
component

testing
and
repair
.
Special
equipment
is
necessary
for
some

of
the
procedures
given
in
this
repair
group
.
If
you
do
not
have

the
equipment
required
to
do
the
job,
it
is
recommended
that

these
repairs
be
left
to
an
authorized
BMW
dealer
.
The
BMW

dealer
is
equipped
with
sophisticated
diagnostic
test
equip-

ment
that
is
capable
of
quicklypinpointing
hard-to-find
fuel
in-

jection
problems
.

NOTE-

"
Wiring
diagrams
for
the
engine
management
system,

can
be
found
at
the
rear
of
the
manual
under
Electri-
cal
Wiring
Diagrams
.

"
For
ignition
system
repairinformation,
see120
Igni-

tion
System
.

"
For
fuel
supply
system
testing
and
repair,
see160



The
engine
control
module
(ECM)
uses
electrical
signals

Fuel
Tank
and
Fuel
Pump
.



from
the
mass
air
flow
sensor,
the
air
and
coolant
temperature

sensors,
the
crankshaft
position/rpm
sensor,
the
knock
sen

Principies
Of
Operation



sors
and
the
oxygen
sensorsas
the
primary
inputs
to
electron-

ically
control
fuel
delivery
and
ignition
timing
.

There
are
five
versions
of
engine
management
systems

usedon
the
E36
cars
.
Each
has
the
same
basic
components

and
operating
principles
.
The
most
notable
difference
is
that

1996
and
later
cars
use
a
sophisticated
OBD
II-compliant
sys-

tem
.
See
Table
a
.

Table
a
.
Engine
Management
System
Variants

Engine
code/year



1
System

4-cy1inder
M42
(1
.8
I)
1992-1995



Bosch
DME
Ml
.7
M44
(1
.91)
1996-1998



~
Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M3
.1
1993-1995
(2.5
I)



Bosch
DME
M3
.3.1
(VANOS)
M52
1996-1998
(3281-
2
.8
I)



Siemens
MS
41
.1
(OBD
II)
1998
(3231
-
2
.5
I)



Siemens
MS
41
.1
(OBD
II)
M-Power
S50US
(M3
-
3
.01)
1995



Bosch
DME
M3
.3
.1
S52US
(M3
-
3
.21)
1997-1998



Siemens
MS
41
.1
(0131)
11)

NOTE-

-
Descriptions
and
procedures
in
the
first
partof
this
re-

pairgroup
refer
to
all
the
various
engine
management
systems
.

"
Particulars
of
each
fuel
injection
system
are
treated
in
separate
sections
in
the
second
part
of
this
repair
group
.

GENERAL

Fig
.1
.



OBD
II
diagnostic
connector
locatíon
.

The
fuel
injection
system
is
completely
electronic
in
opera-

tion
.
Air
flow
is
measured
electronically
via
a
mass
air
flow

sensor
and
additional
sensors
supply
information
about
en-

gine
operating
conditions
.
The
ECM
calculates
the
amount
of
fuel
needed
for
the
correct
air-fuel
ratio
and
actuates
the
fuel

injectors
accordingly
.
The
amount
offuel
metered
to
theen-

gine
is
determined
by
how
long
the
injectors
are
open
.

Airintake
.
Air
entering
the
engine
passes
through
a
pleat-

ed
paper
air
filter
in
the
air
cleaner
.
Intake
air
volume
or
mass

is
then
measured
bya
mass
air
flow
(MAF)
sensor
.
In
al¡
ex-

cept
the
vane
type
sensor
(DME
M1
.7),
a
reference
current
is

used
to
heat
a
thin
wireor
film
in
the
sensor
when
the
engine

is
running
.
The
current
used
to
heat
the
wire/film
is
electroni-

cally
converted
into
a
voltage
measurement
corresponding
to

the
mass
of
the
intake
air
.

Table
b
.
Mass
Air
Flow
Sensor
Variants

System



Al
r
flow
sensor
type

Bosch
DME
M1
.7



Vane
(volume
sensor)

Bosch
DME
M3
.1



Hot
wire
(mass
sensor)

Bosch
DME
M3
.3
.1



Hot
film
(mass
sensor)

Bosch
DME
M5
.2



Hot
film
(mass
sensor)

Siemens
MS
41
.1



Hot
film
(mass
sensor)

"
The
16-pin
OBD
11
diagnostic
connector
is
located
on



NOTE-

the
lower
left
dashpanel
.
See
Fig
.
1
.



On
cars
equipped
wíth
tractioncontrol,
an
additional
throttle
valve
is
controlled
by
an
electronic
throttle
actu-
ator
(motor)
.
This
valve
is
used
for
engine
speed
inter
vention
.
Repair
information
forthis
system
is
notcovered
here
due
to
the
special
electrical
testing
equip-
ment
required
to
service
it
.

FUEL
INJECTION



130-
3

Fuel
metering
.
The
ECM
meters
fuel
bychanging
the



The
engine
management
system
compensates
automatical-
opening
time
(pulsewidth)
of
the
fuel
injectors
.
To
ensure
that



ly
for
changes
in
the
engine
due
to
age,
minor
wear
or
small
injector
pulsewídth
is
the
only
factor
that
determines
fuel
me-



problems,
such
as
a
disconnected
vacuum
hose
.
Asa
result,
tering,fuel
pressure
is
maintained
bya
fuel
pressure
regula-



idle
speed
and
mixture
do
not
need
lo
be
adjustedas
partof
tor
.
The
injectors
are
mounted
lo
a
common
fuel
supply
called



routine
maintenance
.
the
fuel
rail
.

The
ECM
monitors
engine
speed
to
determine
the
duration



NOTE-

ofinjector
openings
.
Other
signals
to
the
ECM
help
determine



Poordriveabilitymaybe
encountered
when
the
batteryis

injector
pulse
time
for
different
operating
conditions
.
A
tem-



disconnected
and
reconnected
.
when
the
battery
is
dis-
connected,
the
adaptive
memory
is
lost
The
system
will
perature
sensor
signals
engine
temperature
for
mixture
adap-



readaptafterabout
ten
minutes
of
drfving
.
tion
.
A
throttle
position
sensor
signals
throttle
position
.
The
exhaust
oxygen
sensor(s)
signal
information
about
combus-
tion
efficiency
for
control
of
the
air-fuel
mixture
.
1992
to
1995



DISA
(Dual
Resonance
Intake
System)
engines
are
equipped
with
a
single
sensor
.
1996
and
later
(OBD
II)
engines
are
equipped
with
an
oxygen
sensor
before



TheE36
4-cylinder
engine
is
equipped
with
a
dual
intake
andone
after
each
catalytic
converter
.
Forexample,the
M52



runner
system,
termed
DISA
.
DISA
offers
the
advantages
of
engine
is
equipped
withfour
oxygen
sensors
.



both
short
and
long
intake
pipes
.
Long
intake
runners
are
most
useful
at
low
to
medium
engine
rpm
for
producing
good
Idle
speed
control
.
ldle
speed
is
electronically
controlled



torque
characteristics
.
Short
intake
runners
produce
hígherviathe
idle
speed
control
valve,
which
maintains
idle
speed
by



horsepower
at
hígher
engine
speeds
.
bypassing
varying
amounts
of
air
around
theclosed
throttle
valve
.
Idle
speed
is
not
adjustable
.



NOTE-

Knock
(detonation)
control
.
Knock
sensors
monitor
and



The
term
DISA
comes
from
the
German
words
Differen-

control
ignition
knock
through
the
ECM
.
The
knock
sensors



zierte
Sauganlage,
and
can
roughlybe
translated
as
"dif-
fering
intake
manifold
configuration
."
See
100
Engine-
function
like
microphones
and
are
able
to
convert
mechanical



General
foradditional
information
on
DISA
operation
.
vibration
(knock)
into
electrical
signals
.
The
ECM
is
pro-

grammed
to
react
to
frequencies
that
are
characteristic
of
en-



Manifold
construction
:
The
intake
manifold
is
a
two-piece
gine
knock
and
adapt
the
ignition
timing
point
accordingly
.



metal
construction,
with
a
pair
of
runners
in
thetop
section
See120
Ignition
System
for
further
details
.



and
four
runners
in
the
lower
section
.
A
butterfly
valve
is
in-
stalled
in
the
lower
section,
enabling
the
DISA
solenoid
toiso-

NOTE-



late
one
pair
of
runners
from
the
other
pair
.
See
Fig
.
2
.

The
1992
M50
engine
is
not
equipped
with
knock
sen-



Operation
.
With
the
DISA
butterfly
valve
closed,
the
pipes
sors
.
All
other
engines
are
equipped
with
two
knock



in
thetop
half
of
the
manifold
act
together
with
the
ram
air
sensors
.



pipes
in
the
lower
halfto
producea
single,
long
air
intake
pipe
for
each
cylinder
.
See
Fig
.
3
.
The
column
of
aír
oscíllating
in

Basic
Engine
Settings



this
combined
pipe
significantly
increases
engine
torque
in
the

medium
rpm
range
.

Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
arenot

adjustable
.
The
adaptive
engine
management
system
is
de-

signed
to
automatically
compensate
for
changes
in
engine
op-

eratingconditions,
although
the
adaptive
range
is
limited
.
Once

these
limits
are
exceeded,
driveability
problems
usually
be-

come
noticeable
.

Above
approximately
4,800
rpm,
the
butterfly
valve
between
the
intake
air
pipes
for
the
two
cylinder
groups
is
opened
.
The
shorter
pipes
in
the
lower
manifold
section
now
become
the

main
suppliers
of
ram
air
to
the
cylinders,yielding
greater
pow-

er
at
the
upper
end
of
the
engine
rpm
range
.
See
Fig
.
4
.

Control
components
.
The
DISA
butterfly
valve
is
actuated

NOTE-



electro-pneumatically
via
the
engine
control
module
(ECM)
.

lf
the
system
adaptive
limits
are
exceeded,
the
Check



The
valve
begins
to
open
as
engine
speed
rises
aboye
4,840

Engine
light
will
most
likely
come
on,
indicating
an



rpmand
closes
below
4,760
rpm
.
The
action
of
the
valve
is
de-
emissions-
related
fault
For
Check
Engine
light
diag-



liberately
delayed
to
prevent
it
from
opening
and
closing
repeat-
nostics,
see100
Engine-General
.



edly
within
a
short
time
.

GENERAL

130-
8



FUEL
INJECTION

Fig
.
8
.



Fuel
pump
relayterminal
identification
.
1.
Peel
back
rubber
boot
on
oxygen
sensor
electrical
har-
ness
connector
(car
wiring
side)
.
With
connector
at-
Oxygen
sensor,
testing



tached
to
sensor,
connect
digital
voltmeter
to
pins
1
(BOSch
systems
only)



and
2
in
rear
of
connector
.
See
Fig
.
10
.

CAUTION-

"
The
information
inthis
sectionapplies
to
Bosch
engine
management
systems
only
.

"
The
Siemens
MS
41
.1
system
uses
resistive-type
oxygen
sensors
.
This
sensor
uses
a
5-volt
refer-
ence
signal
input
and
the
output
to
the
ECM
var-
ees
from
1-5
volts,
in
stepped
increments
based
on
oxygen
content
in
the
exhaust
.

NOTE-

"
On
pre-08D
11(1992-1995)
cars,
there
is
one
oxygen
sensor
mounted
upstream
of
the
catalytic
convert-
er(s)
in
the
exhaust
pipe
.
See
Fig
.
9
.
"
On
OBD
11
cars
(1996-1998)
cars,
there
is
one
oxygen
sensor
before
andone
after
each
catalytic
converter
.

"
OnM52
and
S52US
engines,
the
front
pairof
oxygen
sensors
are
installed
in
the
exhaust
manifolds
.

The
oxygen
sensor
providesan
input
voltage
signal
(0-1
VDC)
to
the
ECM
based
on
the
oxygen
content
in
the
exhaust
gas
.
TO
generate
voltage,
the
sensor
temperature
must
exceed
575°F
(300°C)
.
Therefore
it
ís
electrically
heated
.

NOTE-

"
The
test
given
below
is
not
a
conclusive
test
of
oxygen
sensor
efficiency
and
does
not
test
how
quickly
the
oxygensensor
can
react
to
changing
conditions
.

"
Pin
numbers
and
wirecolors
can
vary
.
Always
check
the
wiring
diagrams
to
conflrm
wire
color
and
pinas-
signment
.

ELECTRICAL
CHECKS
AND
COMPONENT
TESTING

0013135

Fig
.
9
.



Oxygen
sensor
location
(arrow)
ahead
of
catalytic
converter
.
3181
model
with
M42
engine
shown
.

1
.
Black
(ground)
2
.
Grey
(signal)



4
.
White
(heater
circuit)
3
.
White
(heater
circuit)

0013189
Fig
.
10
.
Oxygen
sensor
connector
terminal
identification
(sensor
sede)
.
Terminals
numbers
are
molded
into
connector
.

2
.
Start
engine
.
Oxygen
sensorshould
start
to
output
a
fluctuating
voltage
within
a
short
period
.
If
voltage
is
in-
correct,
turn
engine
off
and
check
preheater
circuit
as
described
below
.

WARNING
-

Exhaust
manifolds
and
pipes
can
be
hot
enough
to
cause
serious
burns
.
Wear
suitable
heavy
gloves
and
other
appropriate
protection
.