EN(H6DO)(diag)-242
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
BN:DTC P0301 CYLINDER 1 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
BO:DTC P0302 CYLINDER 2 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
BP:DTC P0303 CYLINDER 3 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
BQ:DTC P0304 CYLINDER 4 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
5CHECK HARNESS BETWEEN FUEL PUMP
CONTROL UNIT AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between fuel pump control unit and ECM con-
nector.
Connector & terminal
(R122) No. 9 — (B135) No. 33:
(R122) No. 8 — (B136) No. 12:
Is the resistance less than 1
Ω?
Go to step 6.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
between fuel
pump control
unit and ECM
•Poor contact
of fuel pump
control unit and
ECM connector
6CHECK HARNESS BETWEEN FUEL PUMP
CONTROL UNIT AND ECM CONNECTOR.
Measure the resistance of harness between
fuel pump control unit and chassis ground.
Connector & terminal
(R122) No. 9 — Chassis ground:
(R122) No. 8 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 7.Repair the ground
short circuit
between fuel pump
control unit and
ECM.
7CHECK POOR CONTACT.
Check poor contact of ECM and fuel pump
control unit connector.
Is there poor contact of ECM
and fuel pump control unit con-
nector?
Repair the poor
contact of ECM and
fuel pump control
unit connector.
Go to step 8.
8CHECK EXPERIENCE OF RUNNING OUT OF
FUEL.
Has the vehicle experienced
running out of fuel?
Finish the diagno-
sis.
NOTE:
DTC may be re-
corded as a result
of fuel pump idling
while running out
of fuel.
Replace the fuel
pump control unit.
Fuel Pump Control
Unit.>
Step Check Yes No
EN(H6DO)(diag)-268
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
WIRING DIAGRAM:
EN-03738
SBF-5
B47
12
35
46
A3D7D1D2A5D3
2
373635363452B21
E2
ECM
C5B15B4C4B30
431
REAROXYGENSENSOR LH
E25
2
431
REAROXYGENSENSOR RH
E61
E3B22
14
1315E3
B221011129
B424
B47
3456
12
B21
123412131415567816171819910 1120212223 24 25 2627 28 29 3031 32 33
3534 37363938 41404342 4445 47464948 51505352 54
B135
567821943102422 23 2511 12 13 14 1526 2728
16 17 18 1920 2129 30 31 32 33 34 35
B:B134
56 7821943102422 23 2511 12 13 14 1526 2728
16 1718 19 20 2133 34293230 31
A:
16
B134A:
B135B:
B136C:
B137D:
B22
1234567891011 121314 15 16
B136
567821943102422 23 2511 12 13141526 2728
1617 18 19 20 2133 3429323031 35
C:B137
5678219431022 2311 12 13 14 1524 2526
16 1718 19 20 2127 28 29 30 31
D:
12345678
B424
B122
3412
E25E61
MAIN RELAYBATTERY
EE
* : TERMINAL NO. OPTIONAL ARRANGEMENT
***B1
**
B122
EN(H6DO)(diag)-269
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Check the appro-
priate DTC using
the “List of Diag-
nostic Trouble
Code (DTC)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:In this case, it is
not necessary to
inspect DTC
P0420.
Go to step 2.
2CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance of harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B134) No. 4 — (E61) No. 3:
(B134) No. 30 — (E61) No. 4:
(B134) No. 15 — (E25) No. 3:
(B134) No. 30 — (E25) No. 4:
Is the resistance less than 1
Ω?
Go to step 3.Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
3CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
Measure the resistance between rear oxygen
sensor harness connector and chassis ground.
Connector & terminal
(B135) No. 1 — Chassis ground:
Is the resistance less than 1
Ω?
Go to step 4.Repair the open
circuit between
ECM and rear oxy-
gen sensor con-
nector.
4 CHECK EXHAUST SYSTEM.
Check for gas leaks or air suction caused by
loose or dislocated nuts and bolts, and open
hole at exhaust pipes.
NOTE:Check the following positions.
•Between cylinder head and front exhaust
pipe
•Between front exhaust pipe and front catalyt-
ic converter
•Between front catalytic converter and rear
catalytic converter
Is there any fault in exhaust
system?
Repair or replace
the exhaust sys-
tem.
General Descrip-
tion.>
Go to step 5.
5CHECK CATALYTIC CONVERTER.Is there damage on rear face
or front face of catalytic con-
ver ter?
Replace the cata-
lytic converter.
Front Catalytic
Converter.>
Contact the SOA
service center.
EN(H6DO)(diag)-277
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
CF:DTC P0451 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE
SENSOR
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
WIRING DIAGRAM:
EN-03667
B424
312
223230
ECMB135
R47
R60
R15
R1
B98
123
R47
11210
192018
FUEL TANKPRESSURESENSOR
B424
34561278
: TERMINAL NO. OPTIONAL ARRANGEMENT*
**
B98
123456 78910 1112 13 16 1714 15 18 19 2021222324
R60
12
10115634897131412
B135
567821943102422 23 2511 12 13 14 1526 2728
16 17 18 1920 2129 30 31 32 33 34 35
EN(H6DO)(diag)-279
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
CG:DTC P0452 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE
SENSOR LOW INPUT
DTC DETECTING CONDITION:
•Immediately at fault recognition
•GENERAL DESCRIPTION
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
WIRING DIAGRAM:
EN-03667
B424
312
223230
ECMB135
R47
R60
R15
R1
B98
123
R47
11210
192018
FUEL TANKPRESSURESENSOR
B424
34561278
: TERMINAL NO. OPTIONAL ARRANGEMENT*
**
B98
123456 78910 1112 13 16 1714 15 18 19 2021222324
R60
12
10115634897131412
B135
567821943102422 23 2511 12 13 14 1526 2728
16 17 18 1920 2129 30 31 32 33 34 35
EN(H6DO)(diag)-280
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK CURRENT DATA.
1) Turn the ignition switch to OFF.
2) Remove the fuel filler cap.
3) Install the fuel filler cap.
4) Turn the ignition switch to ON.
5) Read the data of fuel tank pressure sensor
signal using Subaru Select Monitor.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
tor.>
Is the measured value less
than –2.8 kPa (–21.0 mmHg, –
0.827 inHg)?
Go to step 2.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.
2CHECK POWER SUPPLY TO FUEL TANK
PRESSURE SENSOR.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 22 (+) — Chassis ground (–):
Is the voltage more than 4.5 V? Go to step 4.Go to step 3.
3CHECK POWER SUPPLY TO FUEL TANK
PRESSURE SENSOR.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 22 (+) — Chassis ground (–):
Does the voltage change by
shaking the ECM harness and
connector?
Repair poor con-
tact in ECM con-
nector.
Contact with SOA
Service Center.
4CHECK INPUT SIGNAL OF ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 32 (+) — Chassis ground (–):
Is the voltage less than 0.2 V? Go to step 6.Go to step 5.
5CHECK INPUT SIGNAL FOR ECM (USING
SUBARU SELECT MONITOR).
Read the data of fuel tank pressure sensor sig-
nal using Subaru Select Monitor.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”.
tor.>
Does the measured value
change by shaking ECM har-
ness and connector?
Repair poor con-
tact in ECM con-
nector.
Go to step 6.
6CHECK HARNESS BETWEEN ECM AND
COUPLING CONNECTOR IN REAR WIRING
HARNESS.
1) Turn the ignition switch to OFF.
2) Remove the rear seat cushion.
3) Separate rear wiring harness and fuel tank
cord.
4) Turn the ignition switch to ON.
5) Measure the voltage between rear wiring
harness connector and chassis ground.
Connector & terminal
(R15) No. 11 (+) — Chassis ground (–):
Is the voltage more than 4.5 V? Go to step 7.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
rear wiring har-
ness connector
•Poor contact
of coupling con-
nector
EN(H6DO)(diag)-281
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
7CHECK HARNESS BETWEEN ECM AND
COUPLING CONNECTOR IN REAR WIRING
HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between ECM and rear wiring harness con-
nector.
Connector & terminal
(B135) No. 30 — (R15) No. 2:
Is the resistance less than 1
Ω?
Go to step 8.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
rear wiring har-
ness connector
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
8CHECK HARNESS BETWEEN ECM AND
COUPLING CONNECTOR IN REAR WIRING
HARNESS.
Measure the resistance of harness between
rear wiring harness connector and chassis
ground.
Connector & terminal
(R15) No. 2 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 9.Repair short circuit
to ground in har-
ness between
ECM and rear wir-
ing harness con-
nector.
9CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel tank
pressure sensor.
2) Measure the resistance of fuel tank cord.
Connector & terminal
(R60) No. 11 — (R47) No. 3:
Is the resistance less than 1
Ω?
Go to step 10.Repair open circuit
in fuel tank cord.
10 CHECK FUEL TANK CORD.
Measure the resistance of fuel tank cord.
Connector & terminal
(R60) No. 2 — (R47) No. 1:
Is the resistance less than 1
Ω?
Go to step 11.Repair open circuit
in fuel tank cord.
11 CHECK FUEL TANK CORD.
Measure the resistance of harness between
fuel tank pressure sensor connector and
engine ground.
Connector & terminal
(R47) No. 2 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 12.Repair ground
short circuit in fuel
tank cord.
12 CHECK POOR CONTACT.
Check poor contact in fuel tank pressure sen-
sor connector.
Is there poor contact in fuel
tank pressure sensor connec-
tor?
Repair poor con-
tact in fuel tank
pressure sensor
connector.
Replace the fuel
tank pressure sen-
sor.
Fuel Tank Pres-
sure Sensor.>
Step Check Yes No
EN(H6DO)(diag)-282
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
CH:DTC P0453 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE
SENSOR HIGH INPUT
DTC DETECTING CONDITION:
•Immediately at fault recognition
•GENERAL DESCRIPTION
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
WIRING DIAGRAM:
EN-03667
B424
312
223230
ECMB135
R47
R60
R15
R1
B98
123
R47
11210
192018
FUEL TANKPRESSURESENSOR
B424
34561278
: TERMINAL NO. OPTIONAL ARRANGEMENT*
**
B98
123456 78910 1112 13 16 1714 15 18 19 2021222324
R60
12
10115634897131412
B135
567821943102422 23 2511 12 13 14 1526 2728
16 17 18 1920 2129 30 31 32 33 34 35