2009 SUBARU TRIBECA Heat

EN(H6DO)(diag)-95
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
J: DTC P0037 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 2)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION LOW (BANK 1 SENSOR 2), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.

EN(H6DO)(diag)-97
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
(E61) 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 main relay
connector
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”. to EN(H6DO)(diag)-26, Subaru Select Moni-
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. 4 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 7.Go to step 5.

EN(H6DO)(diag)-99
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
K: DTC P0038 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 2)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION HIGH (BANK 1 SENSOR 2), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.

EN(H6DO)(diag)-101
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
2CHECK CURRENT DATA.
1) Turn the ignition switch to OFF.
2) Repair the battery short circuit of harness
between ECM and rear oxygen sensor con-
nector.
3) Turn the ignition switch to ON.
4) 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”. to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 7 A? Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
END.
3CHECK POOR CONTACT.
Check poor contact of ECM connector.
Is there poor contact in ECM
connector?
Repair poor con-
tact in ECM con-
nector.
END.
Step Check Yes No

EN(H6DO)(diag)-102
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
L: DTC P0050 HO2S HEATER CONTROL CIRCUIT (BANK 2 SENSOR 1)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION (BANK 2 SENSOR 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.

EN(H6DO)(diag)-105
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
M: DTC P0051 HO2S HEATER CONTROL CIRCUIT LOW (BANK 2 SENSOR 1)
DTC DETECTING CONDITION:
•Immediately at fault recognition
•GENERAL DESCRIPTION LOW (BANK 2 SENSOR 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.

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”. to EN(H6DO)(diag)-26, Subaru Select Moni-
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)-109
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
N: DTC P0052 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 2 SENSOR 1)
DTC DETECTING CONDITION:
•Immediately at fault recognition
•GENERAL DESCRIPTION HIGH (BANK 2 SENSOR 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.