EN(H6DO)(diag)-107
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1 CHECK POWER SUPPLY TO FRONT OXY-
GEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between front oxygen
(A/F) sensor connector and engine ground.
Connector & terminal
(E24) No. 2 (+) — Engine ground (–):
Is the voltage more than 10 V? Go to step 2.Repair the power
supply line.
NOTE:
In this case, repair
the following item:
•Open circuit
of harness be-
tween main re-
lay and front
oxygen (A/F)
sensor connec-
tor
•Poor contact
in front oxygen
(A/F) sensor
connector
•Poor contact
of main relay
connector
2CHECK GROUND CIRCUIT FOR ECM.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 3 — Chassis ground:
(B134) No. 5 — Chassis ground:
(B137) No. 1 — Chassis ground:
(B137) No. 2 — Chassis ground:
(B137) No. 3 — Chassis ground:
(B137) No. 7 — Chassis ground:
Is the resistance less than 5
Ω?
Go to step 3.Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
engine ground
terminal
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
3CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of front oxygen (A/F) sensor
heater current using Subaru Select Monitor or
general scan tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 0.2 A? Repair the poor
contact of connec-
tor.
NOTE:
In this case, repair
the following item:
•Poor contact
in front oxygen
(A/F) sensor
connector
•Poor contact
of coupling con-
nector
•Poor contact
in ECM connec-
tor
Go to step 4.
4CHECK OUTPUT SIGNAL OF ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 6 (+) — Chassis ground (–):
(B135) No. 7 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 6.Go to step 5.
EN(H6DO)(diag)-108
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
5CHECK OUTPUT SIGNAL OF ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 6 (+) — Chassis ground (–):
(B135) No. 7 (+) — Chassis ground (–):
Does the voltage change by
shaking the ECM harness and
connector while monitoring the
value of voltage meter?
Repair poor con-
tact in ECM con-
nector.
Go to step 6.
6CHECK FRONT OXYGEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between front oxy-
gen (A/F) sensor connector terminals.
Te r m i n a l s
No. 2 — No. 1:
Is the resistance less than 10
Ω?
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following item:
•Open or
ground short
circuit of har-
ness between
front oxygen (A/
F) sensor and
ECM connector
•Poor contact
in front oxygen
(A/F) sensor
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
Replace the front
oxygen (A/F) sen-
sor.
Fr o nt Ox yg en ( A /
F) Sensor.>
Step Check Yes No
EN(H6DO)(diag)-110
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
WIRING DIAGRAM:
EN-03737
SBF-5
B47
12
35
46
A3D1D7D2A5D3
2
3736353452B21
E2
ECM
B11B1B10B6B7C2C3B8B9
413
E24
2
431
E47
E3B22
8
56E3
B222134
B47
3456
12
B22
1234567891011 121314 15 16
3412
E47E24
B135
567821943102422 23 2511 12 13 14 1526 2728
16 17 18 1920 2129 30 31 32 33 34 35
B:
B21
123412131415567816171819910 1120212223 24 25 2627 28 29 3031 32 33
3534 37363938 41404342 4445 47464948 51505352 54
EE
B135B:B136C:B137D:B134A:
7
FRONTOXYGEN(A/F)SENSOR LH
FRONTOXYGEN(A/F)SENSOR RH
MAIN RELAYBATTERY
B136
16101112131415252430
9871718192028212223293231
123456
2726333435
C:
B137
85610 11 12 13 14 157213416
3019 20 2228 29
91718 2521 23 243126 27
D:B122
34561278
*: TERMINAL NO. OPTIONAL ARRANGEMENT
**
B122
A:B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34
Step Check Yes No
1CHECK OUTPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 6 (+) — Chassis ground (–):
(B135) No. 7 (+) — Chassis ground (–):
Is the voltage more than 8 V? Go to step 2.Go to step 3.
EN(H6DO)(diag)-111
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
2CHECK FRONT OXYGEN (A/F) SENSOR
HEATER CURRENT.
1) Turn the ignition switch to OFF.
2) Repair the battery short circuit of harness
between ECM and front oxygen (A/F) sensor
connector.
3) Turn the ignition switch to ON.
4) Read the data of front oxygen (A/F) sensor
heater current using Subaru Select Monitor or
general scan tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 2.3 A? Replace the ECM.
Engine Control
Module (ECM).>
END.
3CHECK OUTPUT SIGNAL OF ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 6 (+) — Chassis ground (–):
(B135) No. 7 (+) — Chassis ground (–):
Does the voltage change by
shaking the ECM harness and
connector?
Repair the battery
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
END.
Step Check Yes No
EN(H6DO)(diag)-114
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK POWER SUPPLY TO REAR OXY-
GEN SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from rear oxygen
sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between rear oxygen
sensor connector and chassis ground.
Connector & terminal
(E25) No. 2 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 2.Repair the power
supply line.
NOTE:
In this case, repair
the following item:
•Open circuit
of harness be-
tween main re-
lay and rear
oxygen sensor
connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
of coupling con-
nector
2CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B134) No. 3 — Chassis ground:
(B134) No. 5 — Chassis ground:
(B137) No. 1 — Chassis ground:
(B137) No. 2 — Chassis ground:
(B137) No. 3 — Chassis ground:
(B137) No. 7 — Chassis ground:
Is the resistance less than 5
Ω?
Go to step 3.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
engine ground
terminal
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
3CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of rear oxygen sensor heater
current using Subaru Select Monitor or general
scan tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 0.2 A? Repair the con-
nector.
NOTE:In this case, repair
the following item:
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
of coupling con-
nector
•Poor contact
in ECM connec-
tor
Go to step 4.
4CHECK OUTPUT SIGNAL OF ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 5 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 7.Go to step 5.
EN(H6DO)(diag)-115
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
5CHECK OUTPUT SIGNAL OF ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 5 (+) — Chassis ground (–):
Does the voltage change by
shaking the ECM harness and
connector while monitoring the
value of voltage meter?
Repair poor con-
tact in ECM con-
nector.
Go to step 6.
6CHECK OUTPUT SIGNAL OF ECM.
1) Disconnect the connector from rear oxygen
sensor.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 5 (+) — Chassis ground (–):
Is the voltage less than 1 V? Replace the ECM.
Engine Control
Module (ECM).>
Repair the battery
short circuit of har-
ness between
ECM and rear oxy-
gen sensor con-
nector. After
repair, replace the
ECM.
Engine Control
Module (ECM).>
7CHECK REAR OXYGEN SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between rear oxy-
gen sensor connector terminals.
Te r m i n a l s
No. 1 — No. 2:
Is the resistance less than 30
Ω?
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following item:
•Open circuit
of harness be-
tween rear oxy-
gen sensor and
ECM connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
Replace the rear
oxygen sensor.
Rear Oxygen Sen-
sor.>
Step Check Yes No
EN(H6DO)(diag)-120
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK IDLE SWITCH SIGNAL.
1) Turn the ignition switch to ON.
2) Operate the LED operation mode for
engine using Subaru Select Monitor.
NOTE:•Subaru Select Monitor
For detailed operation procedure, refer to the
“LED OPERATION MODE FOR ENGINE.”
Does the LED of {Idle Switch
Signal} come on?
Go to step 2.Check the throttle
position sensor cir-
cuit.
382, DTC P2135
THROTTLE/
PEDAL POSI-
TION SENSOR/
SWITCH “A”/“B”
VOLTAGE RATIO-
NALITY, Diagnos-
tic Procedure with
Diagnostic Trou-
ble Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0106.
2CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Check the relative
DTC.“List of Diag-
nostic Trouble
Code (DTC)”
EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0106.
Go to step 3.
3CHECK CONDITION OF MANIFOLD ABSO-
LUTE PRESSURE SENSOR.
Is the manifold absolute pres-
sure sensor installation bolt
tightened securely?
Go to step 4.Securely tighten
the manifold abso-
lute pressure sen-
sor installation
bolt.
4CHECK CONDITION OF THROTTLE BODY.Is the throttle body installation
bolt tightened securely?
Replace the mani-
fold absolute pres-
sure sensor.
Manifold Absolute
Pressure Sensor.>
Tighten the throttle
body installation
bolt securely.
EN(H6DO)(diag)-132
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CONNECT SUBARU SELECT MONITOR OR
THE GENERAL SCAN TOOL, AND READ
DATA.
1) Turn the ignition switch to OFF.
2) Connect the Subaru Select Monitor or gen-
eral scan tool to data link connector.
3) Turn the ignition switch to ON, and the Sub-
aru Select Monitor power switch to ON.
4) Start the engine.
5) Read the voltage of mass air flow sensor
using Subaru Select Monitor or general scan
tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage 0.2 — 4.7 V? Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. Tempo-
rary poor contact
of connector or
harness may be
the cause. Repair
the harness or
connector in mass
air flow sensor.
NOTE:
In this case, repair
the following item:
•Open or
ground short
circuit of har-
ness between
mass air flow
sensor and
ECM connector
•Poor contact
of mass air flow
sensor or ECM
connector
Go to step 2.
2CHECK INPUT SIGNAL OF ECM.
Measure the voltage between ECM connector
and chassis ground while engine is idling.
Connector & terminal
(B135) No. 26 (+) — Chassis ground (–):
Is the voltage more than 0.2 V? Go to step 4.Go to step 3.
3CHECK INPUT SIGNAL FOR ECM (USING
SUBARU SELECT MONITOR).
Measure the voltage between ECM connector
and chassis ground while engine is idling.
Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with Subaru
Select Monitor?
Repair poor con-
tact in ECM con-
nector.
Replace the ECM.
Engine Control
Module (ECM).>
4CHECK POWER SUPPLY TO MASS AIR
FLOW SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air
flow sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between mass air flow
sensor connector and chassis ground.
Connector & terminal
(B3) No. 1 (+) — Chassis ground (–):
Is the voltage more than 5 V? Go to step 5.Repair the open
circuit between
mass air flow sen-
sor and main relay.
5CHECK HARNESS BETWEEN ECM AND
MASS AIR FLOW SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between ECM and mass air flow sensor con-
nector.
Connector & terminal
(B135) No. 26 — (B3) No. 3:
(B135) No. 34 — (B3) No. 2:
(B135) No. 30 — (B3) No. 5:
Is the resistance less than 1
Ω?
Go to step 6.Repair the open
circuit between
ECM and mass air
flow sensor con-
nector.