Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 261

EN(H4DOTC)(diag)-268

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CO:DTC P0461 FUEL LEVEL SENSOR “A” CIRCUIT RANGE/PERFORMANCE

DTC DETECTING CONDITION:

• Detected when two consecutive driving cycles with fault occur.

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-172, DTC P0461 FUEL LEVEL SENSOR “A” CIRCUIT

RANGE/PERFORMANCE, Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-63,

OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-49, PROCE-

DURE, Inspection Mode.>.

CP:DTC P0462 FUEL LEVEL SENSOR “A” CIRCUIT LOW

NOTE:

For the diagnostic procedure, refer to DTC P0463. <Ref. to EN(H4DOTC)(diag)-269, DTC P0463 FUEL LEV-

EL SENSOR “A” CIRCUIT HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

Step

Check

Yes

No

1

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

Check the appropri-
ate DTC using the
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
EN(H4DOTC)(diag)
-87, List of Diagnos-
tic Trouble Code
(DTC).>

Replace the fuel
level sensor and
fuel sub level sen-
sor. <Ref. to
FU(STI)-82, Fuel
Level Sensor.>
<Ref. to FU(STI)-
83, Fuel Sub Level
Sensor.> <Ref. to
FU(w/o STI)-80,
Fuel Level Sen-
sor.> <Ref. to
FU(w/o STI)-81,
Fuel Sub Level
Sensor.>

EN(H4DOTC)(diag)-269

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CQ:DTC P0463 FUEL LEVEL SENSOR “A” CIRCUIT HIGH

DTC DETECTING CONDITION:

• Detected when two consecutive driving cycles with fault occur.

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-176, DTC P0463 FUEL LEVEL SENSOR “A” CIRCUIT

HIGH, Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-63,

OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-49, PROCE-

DURE, Inspection Mode.>.

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is DTC P0462 or P0463 dis-

played on the Subaru Select
Monitor?

Check the combi-
nation meter. <Ref.
to IDI-8, CHECK
FUEL LEVEL
SENSOR,
INSPECTION,
Combination Meter
System.>

Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.
NOTE:

In this case, tem-
porary poor con-
tact of connector,
temporary open or
short circuit of har-
ness may be the
cause.

EN(H4DOTC)(diag)-270

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CR:DTC P04AC EVAP SYSTEM PURGE CONTROL VALVE "B" CIRCUIT LOW

DTC DETECTING CONDITION:

• Detected when 2 consecutive driving cycles with fault occur.

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-178, DTC P04AC EVAP SYSTEM PURGE CONTROL

VALVE "B" CIRCUIT LOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>

TROUBLE SYMPTOM:

Improper idling
CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-63,

OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-49, PROCE-

DURE, Inspection Mode.>.

WIRING DIAGRAM:

• Engine electrical system, without SI-DRIVE <Ref. to WI-32, WITHOUT SI-DRIVE, WIRING DIAGRAM,

Engine Electrical System.>

• Engine electrical system, with SI-DRIVE <Ref. to WI-48, WITH SI-DRIVE, WIRING DIAGRAM, Engine

Electrical System.>

ECM

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17 18 19

20 21

29 30 31

32 33

34 35

B135

B:

5

6

7

8

2

1

9

4

3

10

22 23

11 12 13 14 15

24 25

26

16 17

18 19 20 21

27

28 29

30 31

B137

D:

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34 35
42 43

36 37 38 39

48 49 50 51 52 53 54

40 41

44 45

46 47

E52

E4

1 2

B3

D15

D6

E2

B21

44

11

4

8

E4

2

1

E52

2

1

R68

2

1

B135

B:

R57

R15

10

11

R1

B97

R2

B98

7

10

R68

1 2

B220

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32 35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

R57

B97

1 2

3 4 5

6 7 8 9 10 11 12

EN-09251

B98

2 3 4 5

6 7 8 9

11 12 13 14

17 18 19 20

1

10

15 16

B220

24

23

22

21

B220

4

3

B137

D:

SBF-7

E

FUSE

(RELAY BLOCK)

MAIN RELAY

BATTERY

PRESSURE CONTROL

SOLENOID VALVE ASSY

PURGE CONTROL

SOLENOID VALVE 2

PURGE CONTROL

SOLENOID VALVE 1

EN(H4DOTC)(diag)-271

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK OUTPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM connec-
tor and chassis ground.

Connector & terminal

(B137) No. 15 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step

2.

Go to step

3.

2

CHECK FOR POOR CONTACT.
Check for poor contact of ECM connector.

Is there poor contact of ECM
connector?

Repair the poor
contact of ECM
connector.

Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.
NOTE:

In this case, tem-
porary open or
short circuit of har-
ness or temporary
poor contact of
connector may be
the cause.

3

CHECK POWER SUPPLY TO PURGE CON-
TROL SOLENOID VALVE 2 CONNECTOR.
Measure the voltage between purge control
solenoid valve 2 connector and engine ground.

Connector & terminal

(E52) No. 1 (+) — Engine ground (–):

Is the voltage 10 V or more?

Go to step

4.

Repair the power
supply circuit.

4

CHECK HARNESS BETWEEN ECM AND
PURGE CONTROL SOLENOID VALVE 2
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
purge control solenoid valve 2.
3) Measure the resistance between the purge
control solenoid valve 2 connector and engine
ground.

Connector & terminal

(E52) No. 2 — Engine ground:

Is the resistance 1 MΩ or
more?

Go to step

5.

Repair the ground
short circuit of har-
ness between
ECM connector
and purge control
solenoid valve 2
connector.

5

CHECK HARNESS BETWEEN ECM AND
PURGE CONTROL SOLENOID VALVE 2
CONNECTOR.
Measure the resistance of harness between
ECM connector and purge control solenoid
valve 2 connector.

Connector & terminal

(B137) No. 15 — (E52) No. 2:

Is the resistance less than 1 Ω? Go to step

6.

Repair the harness
and connector.
NOTE:

In this case, repair
the following item:
• Open circuit of
harness between
ECM

connector

and purge control
solenoid valve 2
connector
• Poor contact of
coupling connector