check engine SUBARU LEGACY 1996 Service User Guide

2-7
[TSCO3
ON-BOARD
DIAGNOSTICS
II
SYSTEM

8
.
Diagnostics
for
CHECK
ENGINE
Malfunction
Indicator
Lamp
(MIL)

C
:
CHECK
ENGINE
MALFUNCTION

INDICATOR
LAMP
(MIL)
DOES
NOT
BLINK
AT

A
CYCLE
OF
3
HZ
.

WIRING
DIAGRAM
:

Combination
meter

C14
)

Ignition
B37
i2
No
.
15
switch
SBF-4
FL
1
.25
ECM
a

875

B76
822
E3

E

884

9
10
11
1
121
U
1314
U
1516
43
44
3132
33
34
3536
1
3/
1
38
1
39
1
40
1
41
1
42
1
585960
6162
63
1
64
1
65
1
66
1
67
1
68
1
69
1
70848586
87
8889
1
90
1
91
1
92
1
93
1
94
1
9
51
96

B75B76
i2
i14

It~l
~
12345
67
910
LJ
1
11
1
12
1
13
1
14
1
15
1
16
1
11
1
12345678910111213

822

1234
8
1
11
1
1
141
i6

B2M0511

NOTE
:

For
the
diagnostic
procedure
on
indicator
lamp
(MIL)

does
not
blink
at
a
cycle
of
3
Hz,
refer
to
2-7
[T7C0]*2
.

60

ON-BOARD
DIAGNOSTICS
II
SYSTEM
(78D0]
2-7

8
.
Diagnostics
for
CHECK
ENGINE
Malfunction
Indicator
Lamp
(MIL)

D
:
CHECK
ENGINE
MALFUNCTION

INDICATOR
LAMP
(MIL)
REMAINS
BLINKING

AT
A
CYCLE
OF
3
Hz
.

WIRING
DIAGRAM
:

Combination
meter

i14

B84
Ignition
B37
('52)
switch
No
.
15
ECM

B75
B76822
E3

E
815876
i2
i14
822

910
1112
13141516
1
4
31
2333435
36
1
37
1
3839
1
1040
43
44
56
W7
11
585960
6162
63
64
6566
619
70
~
1~
1
234689
10
1
4858687888990
9192
93949596
IJ
11
1213141516171819
20
2122
11
1
2
1
3
1
4
1
5
1
6
1
78
9
10111213

B2M0511

NOTE
:

For
the
diagnostic
procedure
on
indicator
lamp
(MIL)

remains
blinking
at
a
cycle
of
3
Hz,
referto
2-7
[T7D0]*2
.

61

ON-BOARD
DIAGNOSTICS
II
SYSTEM
[Tyooyl
2-7
10
.
General
Diagnostics
Table

10
.
General
Diagnostics
Table

1
.
FOR
ENGINE

1
23
4
5678
9
10
11
1213

N

ONCdN
C
O
O
a
x
m

Problem
parts
`o
m
v

mj
4'S
O
1>j
T
N
dm
G

~
ON

41
m
~
!d
V
P]
7
0
E
m
~n
N
~o
C
o
O
d
~
~
U
O
c
m~
C
.
.
.
V1
ON
aVa
U
3
C~
0

"

y
dO1OyOQ
~
"O
CN
d7

O
"
0va
l0
0CdyGo
>
"
Vd
da
E
U
"
O
l0
ymC
~
O
NC
N
V
V
4)
N
~
'C
C
.2
7
a
3NmC
oi
mm
o
W
m
.
mU
o~
Symptom
2WFU~Ya
LL
.0
ti
QW

1
Engine
stalls
during
idling
.
O4OOOOO

2
Rough
idling
O
4O
Cl
OO

3
Engine
does
notreturnto
idle
.
O
OO

4Poor
acceleration
O4OOOOO

Engine
stalls
or
engine
sags
or
hesi-
O
D
OOOOOO
fates
at
acceleration
.

6
Surge
O4OOOO

T
Spark
knock
OOOO

8
After
burning
in
exhaust
system
O
Lr
I
O
I

'1
:
The
mark,
D,
indicates
the
symptom
occurring
only
in
cold
temperatures
.

'2
:
For
itemswiththe
mark,
D,ensure
the
secure
installationof
crankshaft
position
sensor
and
camshaft
position
sensor
.

Replacement
is
not
necessary
.

'3
:
Check
fuel
injector,
fuel
pressure
regulator
and
fuel
filter
.

'4
:
Check
ignitor,
ignition
coil
and
spark
plug
.

NOTE
:

Malfunction
of
partsother
than
the
above
is
also
possible
.
Refer
to
1
.
Engine
Trouble
in
General
[K100]
in
Repair
Section
2-3
of

the
Service
Manual

69

2-T
[T11A0]
ON-BOARD
DIAGNOSTICS
11
SYSTEM

11
.
Diagnostics
Chart
with
Trouble
Code

11
.
Diagnostics
Chart
with
Trouble
Code
A
:
DIAGNOSTIC
TROUBLE
CODE
(DTC)
LIST

DTC

No
.

Abbreviation

(Subaru
select
monitor)Item
Page

P0100
QA
Mass
air
flow
sensor
circuit
malfunction
76

P0101
QA
-
RMass
air
flow
sensor
circuit
range/performance
problem
77

P0105
P
-
S
Pressure
sensor
circuit
malfunction
78

P0106
PS
-
R
Pressure
sensor
circuit
range/performance
problem
79

P0115
TW
Engine
coolant
temperature
sensor
circuit
malfunction
80

P0120
THV
Throttleposition
sensor
circuit
malfunction
81

P0121
TH
-
R
Throttleposition
sensor
circuit
range/performance
problem
82

P0125
TW
-
CL
Insufficient
coolant
temperature
for
closed
loop
fuel
control
83

P0130
F02
-
V
Front
oxygen
sensor
circuit
malfunction
84

P0133
F02
-
R
Front
oxygen
sensor
circuit
slowresponse
85

P0135
F02H
Front
oxygen
sensor
heater
circuit
malfunction
86

P0136
R02
-
V
Rear
oxygen
sensor
circuit
malfunction
87

P0139
R02
-
R
Rear
oxygen
sensor
circuit
slowresponse88

P0141
R02H
Rear
oxygen
sensor
heater
circuit
malfunction
89

P0170
FUEL
Fuel
trim
malfunction
90

P0201
INJ1Fuel
injector
circuit
malfunction
-
#1

P0202
INJ2Fuel
injector
circuit
malfunction
-
#2
91
P0203
INJ3Fuel
injector
circuit
malfunction
-
#3

P0204
INJ4Fuel
injector
circuit
malfunction
-
#4

P0301
MIS
-
1
Cylinder
1
misfire
detected

P0302
MIS
-
2
Cylinder
2
misfire
detected
2
P0303
MIS
-
3
Cylinder
3
misfire
detected
9

P0304
MIS
-
4
Cylinder
4
misfire
detected

P0325
KNOCK
Knock
sensor
circuit
malfunction
93

P0335
CRANK
Crankshaft
position
sensor
circuit
malfunction
94

P0340
CAM
Camshaft
position
sensor
circuit
malfunction
95

P0400
EGR
Exhaust
gas
recirculation
flow
malfunction
96

P0403
EGRSOL
Exhaust
gas
recirculation
circuit
malfunction
97

P0420
CAT
Catalyst
system
efficiency
below
threshold
98

P0441
CPC
-
F
Evaporative
emission
control
system
incorrect
purge
flow
99

P0443
CPC
Evaporative
emission
control
system
purge
control
valve
circuit
malfunction
100

P0500
VSP
Vehicle
speed
sensor
malfunction
101

P0505
ISC
Idle
control
system
malfunction
102

P0506
ISC
-
L
Idle
control
system
RPM
lower
than
expected
103

P0507
ISC
-
H
Idle
control
system
RPM
higher
than
expected
104

P0600
-
Serial
communication
link
malfunction
105

P0601
RAM
Internal
control
module
memory
check
sum
error
106

P0703
ATBRK
Brake
switch
input
malfunction
T
107
I

74

5-5b
[TaAO]
SUPPLEMENTAL
RESTRAINT
SYSTEM
(ELECTRIC
SENSOR
TYPE)

4
.
Diagnostics
Chart
for
On-board
Diagnostic
System

4
.
Diagnostics
Chart
for
On-board

Diagnostic
System

A
:
BASIC
DIAGNOSTICS
PROCEDURE

1)
Airbag
warning
light
comes
"ON"
.

2)
Turn
ignition
switch
to
"ON",
(engine
"OFF")
and
observe
airbag
warning
light
.

3)
If
airbag
warning
light
stays
"ON"
after
8
seconds
or
remains
"OFF",
or
comes
back
"ON"
after
30
seconds,
this
indicates

a
current
problem
.
Proceed
to
step
8)
.

If
airbag
warning
light
comes
"ON"
for
8
seconds,
then
goes
out
and
stays
out,
this
indicates
normalsystem
operation
atthis

time
.
Check
the
memory
for
intermittent
problems
by
performing
the
procedure
outlined
in
[T4B0)tr2
"ON-BOARD

DIAGNOSTICS"
.
Proceed
to
step
4)
.

4)
If
trouble
code
indicated,
<
Ref
.
to
[T4D1]*2
-
[T4D2]
.*2>
proceed
to
step
5)
.

If
normal
code
indicated,
<
Ref
.
to
[T4D2]
.
>
proceed
to
step
6)
.

5)
Repairand
replacement,
<
Ref
.
to
[T5P1]
.*2>
proceed
to
step
7)
.

6)
Repair
and
replacement,
<
Ref
.
to
[T5Q1]
.*2>
proceed
to
step
7)
.

7)
Turn
ignition
switch
"ON",
(engine
"OFF")
and
observe
airbag
warning
light
.
If
airbag
warning
light
stays
"ON"
after
8

seconds
or
comes
back
"ON"
after
30
seconds,
proceed
to
step
8)
.

If
airbag
warning
light
comes
"ON"
for
8
seconds,
then
goes
out
and
stays
out,
proceed
to
step
9)
.

8)
Repair
and
replacement
.
<
Ref
.
to
[T4E1]
.*2>
Proceed
to
step
10)
.

9)
Clear
memory
.
<
Ref
.
to
[T4C0]
.z`r2>
Proceed
to
step
10)
.

10)
END

SUPPLEMENTAL
RESTRAINT
SYSTEM
(ELECTRIC
SENSOR
TYPE)
[T4CO]
5-5b

4
.
Diagnostics
Chart
for
On-board
Diagnostic
System

2

L3141
B5mol
15B

2

33

E
;1
1~3141516
B5M01
16B

B
:
ON-BOARD
DIAGNOSTIC

When
the
airbag
system
isin
functioning
condition,
the

airbag
warning
light
will
remain
on
for
8
seconds
and
go

out
when
the
ignition
switch
is
set
to
ON
.

If
there
is
any
malfunction,
the
airbag
warning
light
will

either
stay
on
or
off
continuously
.
In
such
cases,
perform

on-board
diagnostic
in
accordance
with
the
specified
pro-

cedure
to
determine
trouble
codes
.

1)
Turn
ignition
switch
ON
(with
engine
OFF)
.

2)
ConnectDIAG
.
terminal
T
to
No
.
1
terminal
of
diag-
nosis
connector
~2
located
below
lower
cover
.

3)
Check
in
accordance
with
the
trouble
code
indicated

by
the
AIRBAG
warning
light,
and
record
the
trouble

codes
.

4)
Turn
the
ignition
switch
"OFF"
and
remove
the
DIAL
.

terminal
from
No
.1
terminal
of
diagnosis
connector
.

C
:
CLEAR
MEMORY

After
eliminating
problem
as
per
trouble
code,
clear
mem-

oryas
follows
:

Make
sure
ignition
switch
is
ON
(and
engine
off)
.
Connect

one
DIAL
.
terminal
1Q
on
diagnosis
connector
(Z
termi-
nal
No
.
1
.

While
warning
light
is
flashing,
connect
the
other
DIAL
.

terminal
(Z
on
terminal
No
.
2
for
at
least
three
seconds
.

After
memory
is
cleared,
normal
warning
light
flashing
rate

resumes
.
(Warning
light
flashes
every
0
.6
seconds

ON-OFF
operation
.)
Memory
cannotbe
cleared
if
any

problem
exists
.

After
clear
memory
and
then
DIAG
.
terminals
(1)
and
(3),

extract
from
diagnosis
connector
02
.

9

SUPPLEMENTAL
RESTRAINT
SYSTEM
(ELECTRIC
SENSOR
TYPE)
[T5H11
5-5b

5
.
Diagnostics
Chart
with
Trouble
Code

H
:
TROUBLE
CODE
31

DIAGNOSIS
:

"
Airbag
control
module
is
faulty
.

"
Airbag
main
harness
circuit
is
open
.

"
Fuse
No
.
16
is
blown
.

"
Body
harness
circuit
is
open
.

1
1
.
Airbag
control
module
inspection

1
2
.
Airbag
main
harness
Inspection

1
3
.
Fuse
No
.
16
inspection

CAUTION
:

Before
performing
diagnostics
on
airbag
system,
turn

ignition
switch
"OFF",
disconnect
battery
ground
cable

and
then
wait
at
least
20
seconds
.

After
20
seconds
elapse,
remove
instrument
panel
lower
cover,
and
disconnect
(AB3)
and
(AB8),
(AB9)
and

(AB10)
.

1
.
AIRBAG
CONTROL
MODULE
INSPECTION

1)
Disconnect
connector
(AB6)
fromairbag
control
mod-

ule
<
Ref
.
to
5-5
[W6A0].*2
>,
and
connect
it
to
test
har-

ness
B2
connector
(8B)
.

2)
Connect
battery
ground
cable
and
turn
ignition
switch

"ON"
(engine
off)
.

3)
Measure
voltage
across
connector
(5B)
terminal
and

chassis
ground
.

CHECK
:
Connector
&
terminal

(5B)
No
.
5
(+)
-
Chassis
ground
(
)
:

Is
voltage
more
than10
V?

Replace
airbag
control
module
.

No
:
Go
to
step
2
.

25

5-5b
[TWO]
SUPPLEMENTAL
RESTRAINT
SYSTEM
(ELECTRIC
SENSOR
TYPE)

5
.
Diagnostics
Chart
with
Trouble
Code

J
:
TROUBLE
CODE
34

DIAGNOSIS
:

9
Airbag
main
harness
circuit
(Passenger)
is
shorted
to

power
supply
.

*Airbag
module
harness
(Passenger)
is
shorted
to
power

supply
.

9
Airbag
control
module
is
faulty
.

r
1
.
Airbag
main
harness
inspection
l

CAUTION
:

Before
performing
diagnostics
on
airbag
system,
turn

ignition
switch
"OFF",
disconnect
battery
ground
termi-

nal
and
thenwait
at
least
20
seconds
.

After
20
seconds
elapse,
remove
instrumentpanel
lower
cover,
and
disconnect
(AB3)
and
(AB8),
(AB9)
and

(AB10)
.

1
.
AIRBAG
MAIN
HARNESS
INSPECTION

1)
Disconnect
connector
(AB6)
from
airbag
control
mod-

ule
<
Ref
.
to
5-5
[W6A0].*2
>,
and
connect
it
totest
har-

ness
132
connector
(8B)
.

2)
Connect
battery
ground
cable
and
turn
ignition
switch

"ON"
(engine
off)
.

3)
Measure
voltage
across
each
test
harness
132
connec-

tor
(5B)
terminal
and
chassis
ground
.

CHECK
:
Connector
&
terminal

(5B)
No
.
6
(+)
-
Chassis
ground
(
)
:

Is
voltage
less
than
1
V?

ves
:
Go
to
next
CHECK

No
:
Replace
airbag
main
harness
.

CHECK
;
Connector
&
terminal

(5B)
No
.
7
(+)
-
Chassis
ground
(
)
:

Is
voltage
less
than
1
V?

,rES
:
Replace
airbag
control
module
.

No
:
Replace
airbag
main
harness
.

28

SUPPLEMENTAL
RESTRAINT
SYSTEM
(ELECTRIC
SENSOR
TYPE)
[T5M1]
5-5b

5
.
Diagnostics
Chart
with
Trouble
Code

1.
Airbag
main
harness
Inspection

M
:
TROUBLE
CODE
43

DIAGNOSIS
:

*
Airbag
main
harness
circuit
(Driver)
is
shorted
to
power

supply
.

Airbag
module
harness
(Driver)
is
shorted
to
power

supply
.

"
Roll
connector
is
shorted
to
power
supply
.

"
Airbag
control
module
is
faulty
.

CAUTION
:

Before
performing
diagnostics
on
airbag
system,
turn

ignition
switch
"OFF",
disconnect
battery
ground
termi-

nal
and
thenwait
at
least
20
seconds
.

After
20
seconds
elapse,
remove
instrument
panel
lower
cover,
and
disconnect
(AB3)
and
(AB8),
(AB9)
and

(AB10)
.

1
.
AIRBAG
MAIN
HARNESS
INSPECTION

1)
Disconnect
connector
(AB6)from
airbag
control
mod-

ule
<
Ref
.
to
5-5
[W6A0]
.*2>,
and
connect
it
to
test
har-

ness
132
connector
(8B)
.

2)
Connect
battery
ground
cable
and
turn
ignition
switch

"ON"
(engine
off)
.

3)
Measure
voltage
across
each
test
harness
132
connec-

tor
(5B)terminal
and
chassis
ground
.

CHECK
:
Connector
&
terminal

(5B)
No
.
1
(+)
-
Chassis
ground
(
)
:

Is
voltage
less
than
1
V?

YES
.
G
o
tonext
CHECK

No
:
Replace
airbag
main
harness
.

CHECK
:
Connector&
terminal

(58)
No
.
14
(+)
-
Chassis
ground
(-)
:

Is
voltage
less
than
1
V?

vES
:
Replace
airbag
control
module
.

No
:
Replace
airbag
main
harness
.

31

SUPPLEMENTAL
RESTRAINT
SYSTEM
(ELECTRIC
SENSOR
TYPE)
[T5N2]
5-5b

5
.
Diagnostics
Chart
with
Trouble
Code

B31
1A

5A
r
.~
..

,fl((
i

1
23
45B
7
89
101
.112131415
761718
I

B5M0123B

i

1
2
31
5
8789
[
lo
l
l1
1
12
1
13
1
14
1
15
1
16
1
17
1
.
t18
20

i

G5M0559
I

2
.
INSPECTION
OF
BODY
HARNESS,
CONNECTOR

AND
AIRBAG
WARNING
LIGHT

1)
Turn
ignition
switch
"OFF"
and
connect
body
harness

connector
(B31)
to
test
connector
A
connector
(1A)
.

2)
Connect
battery
ground
cable
and
turn
ignition
switch

"ON",
(engine
off)
and
connect
connectors
(3A)
and
(4A)
.

CHECK
;
Does
the
airbag
warning
light
come
off?

,rES
:
Go
tostep
3)
.

Go
tonext
~
.

~K
:
Is
there
anything
unusual
to
body
harness?

Repair
body
harness
.

Replace
airbag
warning
light
module
1~
.

NOTE
:

After
problem
has
been
eliminated,
disconnect
connectors

(3A)
and
(4A)
.

3)
Turn
ignition
switch
"OFF",
disconnect
battery
ground

cable
and
then
wait
at
least
20
seconds,
and
re-connect

connectors
(AB1)
and
(B31)
.

4)
Remove
instrument
panel
lower
cover
and
disconnect

(AB3)
with
(AB8),
then
disconnect
connector
(AB6)from

airbag
control
module,
<
Ref
.
to
5-5
[W6A0]
.*2
>
and

connect
it
to
test
harness
132
connector
(8B)
.

5)
Connect
battery
ground
cable
and
turn
ignition
switch

"ON,"
(engine
off)
and
connect
connectors
(6B)
and
(7B)
.

CHECK
:
Does
the
airbag
warning
light
come
on?

0
:
Go
to
step
3
.

No
:
Replace
airbag
main
harness
.

NOTE
:

After
problem
has
been
eliminated,
disconnect
connectors

(6B)
and
(7B)
.

33