
CHARGING
SYSTEM
TROUBLESHOOTING
.............
.
.
.
.
.121-2
Charging
System
Quick-Check
...
.
..
.
...
.
121-2
Static
current
draw,
checking
........
.
...
.
121-2
BATTERY
SERVICE
....................
121-3
Battery
Testing
.
.
.
.
.
.........
.
........
.
121-3
Hydrometer
Testing
.
...
.
.
.
...
.
.........
121-3
Battery
Open-Circuit
Voltage
Test
....
.
....
121-4
Battery
Load
Voltage
Test
.
.
.
.
.
.
.........
121-4
Battery
Charging
.
.
.
.
...
.
.
.
.
.
.
.
.........
121-4
ALTERNATOR
SERVICE
.
.
.
.
.
.
.....
.
...
121-4
Chargingsystem,checking
.
.
.
.
.
.........
121-4
Alternator,
removingand
installing
(4-cylinder
engine)
....
.
.
.
.
.
.
.
.........
121-5
Alternator,
removingand
installing
(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.........
121-6
GENERAL
The
charging
system
consists
of
a
belt-driven
alternator
with
integral
voltage
regulator
and
a
battery
mounted
in
the
luggage
compartment
.
Various
versions
of
alternators,
voltage
regulators,
starters,
and
batteries
are
used
in
the
E36
cars
.
It
is
important
to
re-
place
components
according
tothe
original
equipment
speci-
fication
.
Check
with
an
authorized
BMW
dealer
for
specific
application
and
parts
information
.
WARNING
-
"
Weargoggles,
rubbergloves,
and
a
rubberapron
when
working
around
batteries
and
battery
acid
(electrolyte)
.
"
Battery
acid
contains
sulfuric
acid
and
can
cause
skin
irritation
and
burning
.
ff
acid
is
spilled
onyour
skin
or
clothing,
flush
the
area
at
once
with
large
quantities
of
water
.
lf
electrolyte
gets
into
your
eyes,flush
them
with
largequantities
of
clean
wa-
terfor
several
minutes
and
call
a
physician
.
"
Batteries
that
are
being
charged
or
are
fully
charged
give
off
explosive
hydrogen
gas
.
Keep
sparks
and
open
flames
away
.
Do
not
smoke
.
BATTERY,
STARTER,
ALTERNATOR
121-1
121
Battery,
Starter,
Alternator
GENERAL
..
.
...
.
........
.
...
.
.
.
.
.
.
.
.
.
121-1
Voltage
regulator,
removing
and
ínstalling
.
.
.
121-6
Alternator
brushes,
inspecting
and
replacing
.121-7
STARTER
SERVICE
....
.
.
.
.
.
..........
.121-7
Starter
Troubleshootíng
121-7
15
..
.
.
.
.
.
........
.
.
.
Starter,
removing
and
installing
(4-cylinder
engine)
....
.
.
.
............
.
121-8
Starter,
removing
and
installing
(6-cylinder
engine
with
manual
transmission)
..
.
...........
.
...
121-8
Starter,
removing
and
installing
(6-cylinder
engine
with
automatic
transmission)
................
121-9
Solenoid
switch,
removingand
installing
....
121-10
TABLES
a
.
Battery,
Starter
and
Charging
System
Troubleshooting
............
.
.
.
.
:...
........
121-2
b
.
Specific
Gravity
of
Battery
Electrolyte
at
80°F
(27°C)
...............
.
.
..
..........
121-3
c
.
Open-Circuit
Voltage
and
Battery
Charge
........
121-4
d
.
Battery
Load
Test-Minimum
Voltage
.
..........
121-4
CAUTION
-
"
Prior
to
disconnectiog
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
on
page
viii
.
"
Disconnecting
the
battery
cables
may
erase
fault
codes
stored
in
control
unit
memory
.
"
Always
disconnect
the
negative
()
battery
cable
first
and
reconnect
it
last
.
Cover
the
battery
post
with
an
insulating
material
whenever
the
cable
is
removed
.
"
After
reconnecting
the
battery,
the
power
window
motors
must
be
reinitialized
.
See
511
Door
Win-
dows
.
"
Never
reverse
the
battery
cables
.
Even
a
momen-
tary
wrong
connection
can
damage
the
alternatoror
other
electrical
components
.
"
Battery
cables
may
be
the
same
color
.
Label
ca-blebefore
removing
.
GENERAL

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
.

130-
1
4
FUEL
INJECTION
NOTE-
Be
sure
to
retrieve
thrust
washer
behind
fuel
pressure
regulator
on
6-cylinder
engine
.
4
.
Installation
is
reverse
of
removal
.
Replace
O-rings
.
Fuel
pressure
regulator,
replacing
(under
car
mount)
WARNING
-
Fuel
will
be
discharged
.
Do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.
Keep
an
approved
tire
extinguisher
handy
.
On
late
4-
and
6-cylinder
cars,
the
fuel
pressure
regulator
is
mounted
beneath
the
left
sideof
the
car,
under
a
protective
cover
.
See
Fig
.
20
.
0012726
Fig
.
20
.
Fuel
pressure
regulatorlocation
underneath
car
(arrow)
.
Vac-
uum
hose
to
regulator
is
shown
at
A
.
(Protective
cover
has
been
removed
.)
5
.
Installation
is
reverse
of
removal
.
Replace
O-rings
.
BOSCH
DME
Ml
.
7
COMPONENT
TESTS
AND
REPAIRS
BOSCH
DME
Ml
.7
COMPONENT
TESTS
AND
REPAIRS
CA
UTION-
Use
only
a
digital
multimeter
when
testing
compo-
nents
and
wiring
.
Use
of
an
analog
VOM
may
damage
the
engine
control
module
.
4-cylinder
cars
with
M42
engines(1992
to
1995)use
the
Bosch
DME
M1
.7
fuel
injection
system
.
Electrical
tests
of
the
main
and
fuel
pump
relays
and
the
DME
engine
control
module
(ECM)
are
covered
earlier
in
this
section
.
Fuel
pump
tests
arecovered
in
160
Fuel
Tank
and
Fuel
Pump
.
Air
flow
sensor,
testing
and
replacing
DME
M1
.7
fuel
injection
uses
a
volume
air
flow
type
sensor
with
integrated
intake
air
temperature
(IAT)
sensor
.
The
sen-
sor
provides
a
varyingvoltage
signal
to
the
ECM
based
on
the
position
of
the
air
vane
.
As
the
vane
doorswings
open
thepo-
tentiometer
increases
the
voltage
signal
to
the
ECM
.
The
IATsensor
adapts
theoutput
signal
to
the
ECM
based
on
intake
air
temperature
.
1
.
Check
ECM
reference
voltage
to
sensor
:
"
Peel
back
rubber
boot
from
air
flow
sensor
harness
connector
.
"
Turn
ignition
keyon
.
"
Check
for
5
volts
between
terminal
1
of
harness
con-
nector
and
ground
.
See
Fig
.
21
.
"
Turn
ignition
key
off
.
"
If
voltage
is
not
present
or
incorrect,
check
wring
from
ECM
and
check
air
flow
sensor
reference
voltage
out-
put
at
ECM
.
See
Table
h
.
1
.
Working
under
car
below
driver's
seat,
remove
protec-
tive
cover
from
below
fuel
pressure
regulator
.
"
Remove
intake
air
bootfrom
sensor
.
2
.
Remove
vacuum
hosefrom
fuel
pressure
regulator
.
"
Connect
a
digital
multimeter
(ohms)
across
terminais
1
and
2
.
Swing
air
flow
sensor
vane
through
its
travel
3
.
Remove
locking
clip
retaining
fuel
pressure
regulator
.
range
.
Resistance
should
change
steadily
without
in-
terruption
.
4
.
Wrap
a
shop
rag
around
regulator,
then
remove
regula-
"
If
any
faults
are
found,
the
air
flow
sensor
is
faulty
and
tor
from
213
way
valve
by
pullingstraight
out
.
should
be
replaced
.
2
.
Check
air
flow
sensor
potentiometer
:
3
.
Check
IAT
sensor
resistance
:
"
With
harness
connector
disconnected
at
air
flow
sen-
sor,
check
resistance
across
sensor
terminais
4
and
5
of
air
flow
sensor
.
Compare
tests
results
to
values
in
Table
d
given
later
.
If
any
faults
are
found,
the
air
flow
sensor
should
be
replaced
.

BOSCH
DME
MM
AND
M33
.1
COMPONENT
TESTS
AND
REPAIRS
Consult
Table
a
for
engine
application
information
for
the
Bosch
DME
3
.1
and
3
.3.1
systems
.
The
DME
3
.1
and
DME
3
.3
.1
systems
are
similar
in
opera-
tion,
with
knock
control
and
VANOS
operation
being
the
key
differences
.
DME
3
.1
engines
arenot
equipped
with
VANOS
or
knock
detectors,
while
the
DM
E3
.3
.1
system
is
.
CA
UTION-
Use
onty
a
digital
multimeter
when
testing
wiring
.
Use
of
an
analog
VOM
may
damage
the
engine
control
module
.
Fig
.
25
.
Mass
air
flow
sensor
.
Hot
wire
sensor
usedon
carswith
DME
Electrical
tests
of
the
main
and
fuel
pump
relays
and
the
3
.1
(1992
6-cylinder
models)
.
DME
engine
control
module
(ECM)
are
covered
earlier
in
this
section
.
Fuel
pump
tests
are
covered
in
160
Fuel
Tank
and
CAUTION-
Fuel
Pump
.
Use
only
a
digital
multimeter
when
checking
the
mass
air
flow
sensor
.
An
analog
meter
can
dam-
Mass
Air
Flow
Sensor
age
theair
flow
sensor
.
There
are
two
types
of
mass
air
flow
sensors
used
onthe
1
.
Disconnect
air
flow
sensor
from
air
cleaner
only
.
Leave
cars
covered
by
this
section
.
Testing
procedures
vary
de-
it
connected
to
duct
leading
to
intake
manifold
and
pending
on
type
installed
.
The
airflow
sensor
is
not
adjustable
leave
wiring
harness
connected
.
and
must
only
be
tested
with
a
digital
multimeter
.
Mass
Air
FlowSensor
Variants
"
1992
M50
engine
DME
M3
.1
.
.
.
.
...
..
mass
air
flow
sensor-hot
wire
"
1993-1995
M50
and
S50US
DMEM33
.1)
.
...
...
.
mass
air
flow
sensor-hot
film
Mass
air
flow
sensor
(hot
wire),
testing
and
replacing
When
the
engine
is
running,
a
current
is
used
to
heat
a
thin
wire
in
the
center
of
the
sensor
.
See
Fig
.
25
.
The
current
in
the
wire
is
regulated
to
maintain
a
temperature
of
100°C
more
than
the
air
passing
over
it
.
The
current
used
to
heat
the
wire
is
electronically
conneced
into
a
voltage
measurement
corre-
sponding
to
the
mass
of
intake
a¡
r
.
To
keep
the
wire
clean,
it
is
heated
to
a
temperature
of
about
1,000°C
(1,830°F)
for
one
second
.
This
"burn-off"
cycle
takes
place
automatically,
four
seconds
after
the
engine
is
tumed
off
.
lf
thehot
wire
breaks
or
if
there
is
no
output
from
the
air
flow
sensor,
the
ECM
automatically
switches
to
a
"limp-home"
mode
and
tucos
on
the
Check
Engine
light
.
The
engine
can
usually
be
started
and
driven
.
The
air
flow
sensor
has
no
inter-
nal
moving
parts
and
cannot
be
serviced
.
FUEL
INJECTION
130-
1
7
2
.
Start
engine
and
run
it
to
normal
operating
temperature
.
3
.
Rev
engine
toat
least
2,500
rpm,then
shut
it
off
.
Look
through
meter
at
hot
wire
.
After
approximately
four
sec-
onds
wire
should
glow
brightly
for
about
one
second
.
NOTE
-
If
the
wire
glowsas
specified,
then
the
airflow
meter
and
ECM
are
probably
operating
correctly
.
lf
the
wire
does
not
glow,
continue
testing
.
4
.
lf
the
wire
does
not
glow,
remove
air
flow
sensor
and
look
through
it
to
see
if
wire
is
broken
.
lf
wire
is
broken,
meter
will
have
to
be
replaced
.
5
.
Reinstall
air
flow
sensor
and
harness
connector
.
Peel
back
rubber
bootfrom
harness
connector
.
Working
from
rear
of
connector,
connect
digital
voltmeter
across
terminals
1
and
4
.
See
Fig
.
26
.
6
.
Start
and
rev
engine
toat
least
2,500
rpm,thenshut
it
off
.
After
about
4
seconds,
voltage
should
riseto
about
4
volts
for
about
one
second
.
lf
voltage
is
present,
but
wire
does
not
glow,
air
flow
sensor
is
faulty
and
should
be
replaced
.
7
.
lf
voltage
is
not
present
in
step
6,
turn
ignition
key
on
and
check
for
voltage
and
ground
at
sensor
.
There
should
beground
at
pin
4
.
There
should
be
positive
(+)
battery
voltage
at
pin
2
.
BOSCH
DME
M3
.1
AND
M32
.1
COMPONENT
TESTS
AND
REPAIRS

130-18
FUEL
INJECTION
The
engine
coolant
temperature
(ECT)
sensor
sends
con-
tinuous
engine
coolant
temperature
information
to
the
ECM
.
Fig
.
26
.
Mass
air
flow
sensor
terminalidentifcation
on
carswith
DME
As
temperature
increases
sensor
resistance
decreases
.
M3
.1
fuel
injection
.
Mass
air
flow
sensor
(hot
film),
testing
and
replacing
MOTE-
A
burn-off
cycle
is
not
used
on
hot
film
sensors
.
8
.
With
ignition
off,
disconnect
harness
connector
from
air
ECT
Sensor
Location
flow
sensor
.
Using
a
digital
multimeter,
check
resis-
"
M50/S50US
engine
............
left
side
of
cylinder
tance
at
terminals
listed
.
head
under
intake
manifold
Air
Flow
Sensor
Test
Values
(DMEM3
.1)
"
Terminals
5
and
6
.
.
.
.........
..
.
..
....
3-4
ohms
If
any
faults
are
found,
check
wiring
lo
and
from
the
ECM
.
Make
ECM
pinout
test
as
listed
in
See
Table
i
.
Main
power
to
air
flow
sensor
comes
from
DME
main
relay
.
On
cars
with
DME
M3
.3
.1
a
hot
film
mass
air
flow
sensor
is
used
.
When
the
engine
is
running,
a
current
is
used
lo
heat
a
thinfilm
in
the
center
of
the
sensor
.
This
current
is
electroni-
cally
converted
into
a
voltage
measurement
corresponding
to
the
mass
of
intake
air
.
If
thehot
film
breaks
or
if
there
is
no
output
from
the
air
flow
sensor,
the
ECM
automatically
switches
to
a
"limp-home"
mode
and
tucos
on
the
Check
Engine
light
.
The
engine
can
usually
be
started
and
driven
.
The
air
flow
sensor
has
no
inter-
nal
moving
parts
and
cannot
be
senricedor
adjusted
.
CA
UTION-
Use
only
a
digital
multimeter
when
checking
the
mass
air
flow
sensor
.
An
analogmetercan
dam-
age
the
air
flow
sensor
.
BOSCH
DME
M3
.
1
AND
M32
.1
COMPONENT
TESTS
AND
REPAIRS
1
.
Disconnect
harnessconnector
from
air
flow
sensor
.
2
.
Turn
ignition
on
and
check
for
voltage
and
ground
at
connector
.
There
should
beground
at
pin
1
.
There
should
be
positive
(+)
battery
voltage
at
pin
3
.
If
any
faults
are
found,
check
wiring
to
and
from
ECM
.
Make
ECM
pinout
test
.
See
Table
j
.
NOTE-
Positive
(+)
battery
voltage
to
air
flow
sensor
comes
from
DME
main
relay
when
the
ignition
is
switch
on
orengine
running
.
Engine
coolant
temperature
(ECT)
sensor,
testing
and
replacing
0012704
Fig
.
27
.
Engine
coolant
temperature
(ECT)
sensor
(A)
is
located
be-
neath
top
engine
cover
(B)
and
crankcase
vent
hose
(C)
.
M52
engine
shown
.
M50
is
similar
.
1
.
Check
ECM
reference
voltage
to
sensor
:
"
Disconnect
harnessconnector
from
ECT
sensor
.
"
Turn
ignition
keyon
.
"
Check
for
5
volts
between
supply
voltage
wire
(brown/red)
wire
of
harness
connector
and
ground
.
"
Turn
ignition
key
off
.
"
If
voltage
is'
not
present
or
incorrect,
check
wiring
from
ECM
and
check
referencevoltage
output
at
ECM
(pin
78)
.
See
Table
i
(DM
E
3
.1)
or
Table
j
(DME
3
.3
.1)
2
.
Check
ECT
sensor
resistance
:
"
With
harnessconnector
disconnected,
check
resis-
tance
acrosssensor
terminals
.
"
Compare
tests
results
to
values
in
Table
f
.

Tableh
.
ECM
Pin
Assignment--Bosch
DME
M1
.7
Pin
1
Signal
1
Component/function
1
Signal
45
Notused
46
Notused
47
Notused
48
Output
A/C
compressor
cut-out
Compressor
control
relay,
terminal
85
49
Notused
50
Notused
51
Output
Cyl
.
4
ignition
coil
control
Cyl
.
4
ignition
coil
52
Output
Cyl
.
2
ignition
coil
control
Cyl
.
2
ignition
coil
53
Not
used
54
Input
Battery
voltage
from
engine
control
module
Engine
control
module
relay,
terminal
87a
55
Ground
Ground,
ignition
Ground
point
56
Input
Ignition
switch,
terminal
15
Ignition
switch,
terminal
15
57
Notused
58
Not
used
59
Output
Throttleposition
sensor
and
volume
air
flow
sensor
Reference
voltage
(5
VDC)
60
Input
Programming
voltage
Data
link
connector
61
Notused
62
Notused
63
Notused
64
Input
Ignition
timing
intervention
Transmission
control
module
(EGS)
65
Input
Drive
range
P/N
Automatic
transmission
range
switch
66
Notused
67
Input
Crankshaft
position
RPM
sensor
Crankshaft
position
RPM
sensor
68
Input
Crankshaft
position
RPM
sensor
Crankshaft
position
RPM
sensor
69
Notused
70
Input
Oxygen
sensor
signal
Heated
oxygen
sensor
71
Ground
Oxygen
sensor
signal
ground
Heated
oxygen
sensor
72
Notused
73
Input
Vehicle
speed
signal
Instrument
cluster
74
Output
Engine
speed
signal
Instrument
cluster
75
Not
used
76
Input
Volume
air
flow
sensor
Volume
air
flow
sensor
77
Input
Intake
air
temperature
sensor
(IAT)
Intake
air
temperature
sensor
(IAT)
78
Input
Engine
coolant
temperature
Engine
coolant
temperature
sensor
79
Notused
80
Not
used
81
Input
Drive-away
protection
signal
(code)
On-boardcomputer
82
Not
used
83
Notused
84
Not
used
85
Input
A/C
pressure
Pressure
switch
86
Input
A/C
switch
Integrated
climate
regulation
control
module
87
Output
RxD
diagnosisdata
line
Data
link
connector
88
Output-Input
TxD
diagnosisdata
line
l
Data
link
connector
FUEL
INJECTION
130-
2
9
ECM
PIN
ASSIGNMENTS

Table
i
.
ECM
Pin
Assignment-Bosch
DME
M3
.1
Pin
Signal
Component/function
2
ignal
FUEL
INJECTION
130-
3
1
45
vacant
-
46
vacant
-
-
47
vacant
-
-
48
output
A/C
compressor
control
A/C
compressor
disabled
via
compressor
control
relay
49
vacant
-
-
50
output
Ignition
control
(terminal
1),cyl
.
n
o
.
4
Primary
signal,
ignition
coil
cyl
.
n
o
.
4
51
output
Ignition
control
(terminal
1),cyl
.
n
o
.
6
Primary
signal,
ignition
coil
cyl
.
no
.
6
52
output
Ignition
control
(terminal
1),cyl
.
n
o
.
5
Primary
signal,
ignitioncoil
cyl
.
no
.
5
53
vacant
-
54
input
Power
supply
Battery
voltage
(+)
from
main
relay
terminal
87
55
ground
Ground
Ground
for
ignition
control
56
input
Power
supply
(terminal
15)
Batteryvoltage
(+)
with
key
on
or
engine
running
57
vacant
-
-
58
vacant
-
-
59
output
Throttleposition
sensor
Throttleposition
sensorsupply
voltage
(5
VDC)
60
input
Data
link
connector
Programming
voltage
61
vacant
-
-
62
vacant
-
-
63
vacant
-
-
64
input
Ignition
timing
intervention
from
A/T
control
module
(only
active
during
gearshift)
65
input
Automatic
transmission
(A/T)
range
switch
Transmission
park
or
neutral
signal
66
vacant
-
-
67
input
Engine
speed/crankshaft
position
sensor
Crankshaft
position/rpm
(voltage
(VAC)
between
pins
67
and
68)
68
input
Engine
speed/crankshaft
position
sensor
Crankshaft
position/rpm
(voltage
(VAC)
between
pins
67
and
68)
69
vacant
-
-
70
input
Oxygen
sensor
Oxygen
sensor
signal
(0-1
VDC
fluctuating
with
engine
running)
71
ground
Oxygen
sensor
Oxygen
sensor
signal
ground
72
vacant
-
-
73
input
Road
speed
Road
speed
signal
from
instrument
cluster
74
output
Engine
speed
(TD)
Engine
speed
(TD)
signalto
instrument
cluster
75
vacant
-
-
76
vacant
-
-
77
input
Intakeair
temperature
(IAT)
sensor
Intake
air
temperature
(0-5
V,
temperaturedependent)
78
input
Engine
coolant
temperature
(ECT)
sensor
Engine
coolant
temperature
(0-5V,
temperature
dependent)
79
vacant
-
-
80
vacant
-
-
81
input
On-boardcomputer
Drive-away
protection
enable
82
vacant
-
-
83
vacant
-
-
84
vacant
-
-
85
input
A/C
pressure
switch
From
Integrated
climate
control
module
via
A/C
pressure
switch
86
input
A/C
compressor
on
From
Integrated
climate
control
module
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)signal
to
pin
15
in
Data
link
connector
88
input/output
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
20
in
Data
link
connector
ECM
PIN
ASSIGNMENTS

Table
j.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
Pin
~
Signal
1
Componentffunction
1
signal
FUEL
INJECTION
130-
33
45
ground
Ignition
circuit
shield
Ground
shieldfor
ignition
circuit
monitoring
46
output
Fuel
consumption
(KVA
signal)
To
instrument
cluster
47
output
Crankshaft
rpm
Engine
speed
(TD)
signal
to
instrument
cluster
48
output
A/C
compressor
control
A/C
compressor
relay
terminal
85
49
vacant
-
-
50
output
Ignition
coil
control,
cyl
.
1
Primary
signal,
ignition
coil
1
51
output
Ignition
coil
control,
cyl
.
2
Primary
signal,
ignition
coil
2
52
output
Ignition
coil
control,
cyl
.
3
Primary
signal,
ignition
coil
3
53
vacant
-
-
54
input
Power
supply
Battery
voltagefrom
main
relay
(terminal
87a)
55
ground
Ground
Ground
for
ignition
control
56
input
Power
supply
(terminal15)
Batteryvoltage
with
key
on
or
engine
running
57
input
Ignition
timing
intervention
From
A/T
control
module
58
vacant
-
-
59
output
Throttleposition
sensor
(TPS)
Voltage
supply
to
TPS
(5
VDC)
60
input
Programming
voltage
Data
link
connector
61
vacant
-
-
62
vacant
-
-
63
vacant
-
-
64
input
A/C
on
signal
From
integrated
climate
control
module
65
input
A/C
pressure
signal
From
integrated
climate
control
module
via
A/C
pressure
switch
66
input
On-board
computer
Drive-away
protection
enable
(starter
immobilization
relay)
67
vacant
-
-
68
vacant
-
-
69
input
Knock
sensor
#2
(cyl
.
4,5,
6)
Knock
sensor
#2
signal
70
input
Knock
sensor
#1
(cyl
.
1,2,
3)
Knock
sensor
#1
signal
71
ground
Ground
Ground
for
knock
sensors
and
shields
72
vacant
-
-
73
input
Throttleposition
sensor
(TPS)
Throttleposition
signal
74
vacant
-
75
vacant
-
-
76
vacant
-
77
input
Intakeair
temperatura
Intakeair
temperatura
sensor
(0-5
VDC)
78
input
Engine
coolant
temperature
Engine
coolant
temperature
sensor
(0-5
VDC)
79
vacant
-
80
vacant
-
-
81
input
Automatic
transmission
gear
positionlneutral
A/T
parkor
neutral
position
signal
safetyswitch
82
vacant
-
-
83
vacant
-
-
84
vacant
-
-
85
vacant
-
-
86
vacant
-
-
87
input
Diagnostic
connector
(RxD)
Diagnostic
RxD
(receive)
signal
to
pin
15
in
Data
link
connector
88
input/output
Diagnostic
connector
(TxD)
Diagnostic
TxD
(transmit)
signal
to
pin
20
in
Data
link
connector
ECM
PIN
ASSIGNMENTS