1996 SUBARU LEGACY Fuel system

ON-BOARD
DIAGNOSTICS
II
SYSTEM
[T10BS0]
2_7

10
.
Diagnostics
Chart
with
Trouble
Code

WIRING
DIAGRAM
:

S
.M
.J
.

884891
R1
R47

Fuel
tank
pressure
sensor
ECM

75-

884R41

u
uu
u
1
0
11
2
~25101152T4252627
2829
0
4444
61
49
80
1
2

B2M1019

29

2-7
[T10BS1)
ON-BOARD
DIAGNOSTICS
II
SYSTEM

10
.
Diagnostics
Chart
with
Trouble
Code

Data
link
connector
(for
Subaru
select
monitor
and
OBD-II
general
scan
tool)

)
'
~
'~A~
~
Data
link
connector
(for
Subaru
select
monitor
only)

82M1016A]

TNKP
(F43)

0
.
10
k
P
a
1
mmHg
H2M
1326

TNKP
(F43)

0
.
10
k
P
a
1
mmHg

H2M1326

CONNECT
SUBARU
SELECT
MONITOR
OR
10BS1
THE
OBD-II
GENERALSCAN
TOOL,
AND

READ
DATA
.

1)
Turn
ignition
switch
to
OFF
.

2)
Remove
fuel
filler
cap
.

3)
Install
fuel
filler
cap
.

4)
Connect
Subaru
Select
Monitor
or
the
OBD-II
general

scan
toolto
data
link
connector
.

5)
Turn
ignition
switchto
ON
and
Subaru
Select
Monitor

or
the
OBD-II
general
scan
tool
switch
to
ON
.

6)
Read
the
data
onSubaru
Select
Monitoror
the
OBD-II

general
scan
tool
.

o
Subaru
Select
Monitor
Designate
mode
using
functionkey
.

Function
mode
:
F43

o
F43
:
Display
shows
pressure
signal
value
sent
from
fuel

tank
pressure
sensor
.

CHECK
:
Is
the
value
less
than-2
.8
kPa
in
function

mode
F43?

,rES
:
Go
to
step
10BS2
.

No
:
Go
to
next
CHECK
CHECK
:
Is
the
value
more
than2
.8
kPa
in
function

mode
F43?

,rES
:
Go
to
step
10BS4
.

No
:
Repair
harness
and
connector
.

NOTE
:

In
this
case,
repair
the
following
:

9
Open
or
short
circuit
in
harness
between
fuel
tank
p

sure
sensor
and
ECM
connector

"
Poor
contact
in
coupling
connector
(B97)

"
Poor
contact
in
fuel
tank
pressure
sensor

"
Poor
contact
in
ECM
connector

"
OBD-II
general
scan
tool

For
detailed
operation
procedures,
referto
the
OB

General
Scan
Tool
Instruction
Manual
.

30

res-

D-II

ON-BOARD
DIAGNOSTICS
II
SYSTEM
[TIossz]
2-7
10
.
Diagnostics
Chart
with
Trouble
Code

TNKP
(F43)

0
.
10
k
P
a
1
mmHg
H2M
1326

CHECK
INPUT
SIGNAL
FOR
ECM
.
(USING

10BS2
VOLTAGE
METER
AND
SUBARU
SELECT

MONITOR
.)

1)
Measure
voltage
between
ECM
connector
and
chassis

ground
.

CHECK
;
Connector
&
terminal

(884)
No
.
21
(+)
-
Chassis
ground
(
)
:

Is
the
voltage
more
than4
.5
V?

YES
:
Go
to
nextstep
2)
.

No
:
Go
to
next
CHECK

CHECK
:
Does
the
voltage
change
more
than
4
.5
Vby

shaking
harness
and
connector
of
ECM
while

monitoring
the
value
with
voltage
meter?

0
:
Repairpoorcontact
in
ECM
connector
.

No
:
Replace
ECM
.

2)
Measure
voltage
between
ECM
and
chassis
ground
.

CHECK
:
Connector
&
terminal
(B84)
No
.
4
(+)
-
Chassis
ground
(
)
:

Is
the
voltage
less
than
0
.2
V?

,mss
:
Go
to
step
10BS3
.

No
:
Go
to
next
step
3)
.

3)
Read
data
onSubaru
Select
Monitor
.

9
Subaru
Select
Monitor

Designate
mode
using
function
key
.

Function
mode
:
F43

9
F43
:
Display
shows
pressure
signal
value
sent
from
fuel

tankpressure
sensor
.

31

2-7
[T1oBS3]
ON-BOARD
DIAGNOSTICS
II
SYSTEM

10
.
Diagnostics
Chart
with
Trouble
Code

CHECK
:
Does
the
value
change
more
than
-2
.8
kPa

by
shaking
harness
and
connector
of
ECM

while
monitoring
the
value
with
Subaru

select
monitor?

,rES
:
Repair
poor
contact
in
ECM
connector
.

No
:
Go
to
step
10BS3
.

B2M0927

R47
1z
a

L
E

H2M1255B
I

CHECK
HARNESS
BETWEEN
ECMAND

10BS3
FUEL
TANK
PRESSURE
SENSOR
CONNEC-

TOR
.

1)
Turn
ignition
switch
to
OFF
.

2)
Detach
right
siderear
quarter
trim
panel
.

3)
Remove
right
siderear
quarter
trim
pocket
.

4)
Detach
right
siderear
quarter
insulator
.

5)
Disconnect
connector
from
fuel
tank
pressure
sensor
.

6)
Turn
ignition
switch
to
ON
.

7)
Measure
voltage
between
fuel
tank
pressure
sensor

connector
and
chassis
ground
.

CHECK
;
Connector
&
terminal

(R47)
No
.
3
(+)
-
Chassis
ground
(
)
:

Is
thevoltage
more
than
4
.5
V?

vES
:
Go
to
nextstep
8)
.

*
Open
circuit
in
harness
between
ECM
and
fuel
tank

pressure
sensor
connector

e
Poor
contact
in
coupling
connector
(B97)

No
:
Repair
harness
and
connector
.

NOTE
:

In
this
case,
repair
the
following
:

32

ON-BOARD
DIAGNOSTICS
II
SYSTEM
[TIoBSa]
2-7
10
.
Diagnostics
Chart
with
Trouble
Code

8)
Turn
ignition
switch
to
OFF
.

9)
Disconnect
connector
from
ECM
.

10)
Measure
resistance
of
harness
between
ECM
and

pressure
sensor
connector
.

CHECK
:
Connector&
terminal

(B84)
No
.
4
-
(R47)
No
.
2
:

Is
the
resistance
less
than
1
09

YES
.
Go
to
next
CHECK
,

No
:
Repair
harness
and
connector
.

NOTE
:

In
this
case,
repair
the
following
:

9
Open
circuit
in
harness
between
ECM
and
fuel
tank

pressure
sensor
connector

9
Poor
contact
in
coupling
connector
(B97)

CHECK
:
Connector
&
terminal

(884)
No
.
20
-
(R47)
No
.
1
:

Is
the
resistance
less
than
1
S2?

,res
:
Go
to
next
step
11)
.

No
:
Repair
harness
and
connector
.

NOTE
:

In
this
case,
repair
the
following
:

e
Open
circuit
in
harness
between
ECM
and
fuel
tank

pressure
sensor
connector

9
Poor
contact
in
coupling
connector
(B97)

33

2-7
IT10BS4]
ON-BOARD
DIAGNOSTICS
II
SYSTEM

10
.
Diagnostics
Chart
with
Trouble
Code

H2M1257B
I

82M0927

11)
Measure
resistance
of
harness
between
fuel
tank

pressure
sensor
connector
and
chassis
ground
.

CHECK
:
Connector
&
terminal
the
kW

CHECK
:
Is
there
poor
contact
in
fuel
tank
pressure

sensor
connector?

vES
:
Repair
poor
contact
in
fuel
tank
pressure
sensor

connector
.

Replace
fuel
tank
pressure
sensor
.
No
:

(R47)
No
.
1
-
Chassis
ground
:

Is
resistance
more
than
500

Go
to
next
CHECK

No
:
Repair
short
circuit
in
harness
between
ECM
and

fuel
tank
pressure
sensor
connector
.

CHECK
HARNESS
BETWEEN
ECM
AND

10BS4
FUEL
TANK
PRESSURE
SENSOR
CONNEC-

TOR
.

1)
Turn
ignition
switch
to
OFF
and
Subaru
Select
Moni-

tor
or
the
OBD-II
general
scan
tool
switch
to
OFF
.

2)
Detach
right
siderear
quarter
trim
panel
.

3)
Remove
right
siderear
quarter
trim
pocket
.

4)
Detach
right
siderear
quarter
insulator
.

34

ON-BOARD
DIAGNOSTICS
II
SYSTEM
[TloBSa1
2-7
10
.
DiagnosticsChart
with
Trouble
Code

TNKP
(F43)

0
.
10
k
P
a
1
mmHg

H2M1326

5)
Disconnect
connector
from
fuel
tank
pressure
sensor
.

6)
Remove
fuel
filler
cap
.

7)
Install
fuel
filler
cap
.

8)
Turn
ignition
switchto
ON
and
Subaru
Select
Monitor

or
theOBD-II
general
scan
tool
switch
to
ON
.

9)
Read
data
onSubaru
select
monitor
or
the
OBD-II
gen-

eral
scan
tool
.

e
Subaru
Select
Monitor

Designate
mode
using
function
key
.

Function
mode
:
F43

CHECK
:
Is
the
value
more
than2
.8
kPa
in
function

mode
F43?

,rES
:
Repair
short
circuit
in
harnessbetween
ECM
and

fuel
tank
pressure
sensor
connector
.

No
:
Replace
fuel
tankpressure
sensor
.

~
OBD-II
general
scan
tool

For
detailed
operation
procedures,
referto
the
OBD-II

General
Scan
Tool
Instruction
Manual
.

35

2_7
[T10BT0]
ON-BOARD
DIAGNOSTICS
II
SYSTEM

10
.
Diagnostics
Chart
with
Trouble
Code

OBD
(FBI)

P0451


H2M
1377

BT
:
DTC
P0451

-
EVAPORATIVE
EMISSION
CONTROL

SYSTEM
PRESSURE
SENSOR

RANGE/PERFORMANCE
PROBLEM

(TNKP
-
F)
-

DTC
DETECTING
CONDITION
:

Two
consecutive
trips
with
fault

I
1OBT1
I
Check
pressure/vacuum
line
.

CAUTION
:

After
repair
or
replacement
of
faultyparts,
conduct

CLEAR
MEMORY
and
INSPECTION
MODES
.

c
Ref
.
to
2-7
[T3D0]
and
[T3E0]
.*2
and
*4
>

WIRING
DIAGRAM
:

S.M
.J
.

B84897
Ri
R47

Fuel
tankpressure
sensor
ECM

L,

884R47

u
u
u
su
1
71
18
1
1
91201211
2
212312412512612712
8
1
2
913011
78
5
go
8T7T
72
444
44
17374759
7
7
123

82M1019

36