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Subaru Legacy III (2000-2003 year). Manual - part 123

EN(H4SO)-104

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

F: DTC P0068 — MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRES-

SURE CIRCUIT RANGE/PERFORMANCE —

• DTC DETECTING CONDITION:

• Two consecutive driving cycles with fault

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode<Ref. to EN(H4SO)-47, OPER-
ATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)-40, OPERATION, Inspection
Mode.> .
• WIRING DIAGRAM:

EN-01123

PRESSURE

SENSOR

B135

B83

B21

E21

B21

ECM

1 2

6 7

14 15

9 10

11 12

3 4

17 18

19 20

B83

1 2 3 4 5 6

E21

1 2 3

5 6 7

22 23

11 12 13 14 15

27 28

16 17 18 19

20 21

: FOR G.C.C COUNTRIES MODEL

: EXCEPT FOR G.C.C COUNTRIES MODEL

EN(H4SO)-105

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

CHECK ANY OTHER DTC ON DISPLAY.
Is any other DTC displayed?

DTC indicated.

Inspect the rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
EN(H4SO)-83, List
of Diagnostic
Trouble Code
(DTC).>

Go to step 2.

CHECK AIR INTAKE SYSTEM.
Are there holes, loose bolts or disconnection of
hose on air intake system?

There are holes, loose bolts or
disconnection of hose on air
intake system.

Repair air intake
system.

Go to step 3.

CHECK PRESSURE SENSOR.
1) Start the engine and warm-up engine until

coolant temperature is greater than 60

(140

F).

2) Place the shift lever in the selector lever in

“N” or “P” position.

3) Turn A/C switch to OFF.
4) Turn all accessory switches to OFF.
5) Read data of intake manifold pressure sen-

sor signal using Subaru Select Monitor or
OBD-II general scan tool.
Is the measured value within the specified
range?

NOTE:

•Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”.
<Ref. to EN(H4SO)-32, Subaru Select Moni-
tor.>
•OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.

Ignition ON 73.3 - 106.6 kPa
(550 - 800 mmHg, 21.65 -
31.50 inHg), Idling 20.0 - 46.7
kPa (150 - 350 mmHg, 5.91 -
13.78 inHg)

Go to step 4.

Replace intake air
temperature sen-
sor and pressure
sensor. <Ref. to
FU(H4SO)-32,
Pressure Sensor.>

CHECK THROTTLE POSITION.
Read data of throttle position signal using
Subaru Select Monitor or OBD-II general scan
tool.
Is the measured value less than the specified
value?

NOTE:

5% when throttle is fully
closed.

Go to step 5.

Adjust or replace
throttle position
sensor. <Ref. to
FU(H4SO)-30,
Throttle Position
Sensor.>

CHECK THROTTLE POSITION.
Does the measured value exceed the specified
value?

85% when throttle is fully open. Replace pressure

sensor. <Ref. to
FU(H4SO)-32,
Pressure Sensor.>

Replace throttle
position sensor.
<Ref. to
FU(H4SO)-30,
Throttle Position
Sensor.>

EN(H4SO)-106

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

G: DTC P0107 — MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRES-

SURE CIRCUIT LOW INPUT —

• DTC DETECTING CONDITION:

• Immediately at fault recognition

EN-01123

PRESSURE

SENSOR

B135

B83

B21

E21

B21

ECM

1 2

6 7

14 15

9 10

11 12

3 4

17 18

19 20

B83

1 2 3 4 5 6

E21

1 2 3

5 6 7

22 23

11 12 13 14 15

27 28

16 17 18 19

20 21

: FOR G.C.C COUNTRIES MODEL

: EXCEPT FOR G.C.C COUNTRIES MODEL

EN(H4SO)-107

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

CHECK CURRENT DATA.
1) Start engine.
2) Read the data of intake manifold absolute

pressure signal using Subaru Select Moni-
tor or OBD-II general scan tool.
Is the measured value less than the speci-
fied value?

NOTE:

•Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”.
<Ref. to EN(H4SO)-32, Subaru Select Moni-
tor.>
•OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.

13.3 kPa (100 mmHg, 3.94
inHg)

Go to step 3.

Go to step 2.

CHECK POOR CONTACT.
Check poor contact in ECM and pressure sen-
sor connector.
Is there poor contact in ECM or pressure sen-
sor connector?

There is poor contact.

Repair poor con-
tact in ECM or
pressure sensor
connector.

Even if MI lights
up, the circuit has
returned to a nor-
mal condition at
this time.

CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector and
chassis ground.

Connector & terminal

(B135) No. 3 (+) — Chassis ground (

−−−−

Does the measured value exceed the specified
value?

4.5 V

Go to step 5.

Go to step 4.

CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector and
chassis ground.

Connector & terminal

(B135) No. 3 (+) — Chassis ground (

−−−−

Does the measured value exceed the specified
value by shaking harness and connector of
ECM while monitoring the value with voltage
meter?

4.5 V

Repair poor con-
tact in ECM con-
nector.

Contact SUBARU
distributor service.

NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM and chassis
ground.

Connector & terminal

(B135) No. 15 (+) — Chassis ground (

−−−−

Is the measured value less than the specified
value?

0.2 V

Go to step 7.

Go to step 6.

CHECK INPUT SIGNAL FOR ECM. (USING
SUBARU SELECT MONITOR.)
Read data of atmospheric absolute pressure
signal using Subaru Select Monitor.
Does the measured value exceed the specified
value by shaking harness and connector of
ECM while monitoring the value with Subaru
Select Monitor?

NOTE:

•Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”.
<Ref. to EN(H4SO)-32, Subaru Select Moni-
tor.>

13.3 kPa (100 mmHg, 3.94
inHg)

Repair poor con-
tact in ECM con-
nector.

Go to step 7.

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