2009 SUBARU TRIBECA check engine

EN(H6DO)(diag)-163
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
AJ:DTC P0128 COOLANT THERMOSTAT (COOLANT TEMPERATURE BELOW
THERMOSTAT REGULATING TEMPERATURE)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE), Diagnostic Trouble Code
(DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
Thermostat remains open.
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
Step Check Yes No
1CHECK VEHICLEHas the vehicle driven or idled
with the engine partially sub-
merged under water?
In this case, it is
not necessary to
inspect DTC
P0128.
Go to step 2.
2CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Check the appro-
priate DTC using
the “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
Go to step 3.
3CHECK ENGINE COOLANT.Are the coolant level and mix-
ture ratio of engine coolant to
anti-freeze solution correct?
Go to step 4.Replace engine
coolant. CO(H6DO)-10,
REPLACEMENT,
Engine Coolant.>
4CHECK RADIATOR FAN.
1) Start the engine.
2) Check radiator fan operation.
Does the radiator fan continu-
ously rotate for more than 3
minutes during idling?
Repair radiator fan
circuit. CO(H6DO)-21,
Radiator Main Fan
and Fan Motor.>
and CO(H6DO)-25,
Radiator Sub Fan
and Fan Motor.>
Replace the ther-
mostat. CO(H6DO)-14,
Thermostat.>

EN(H6DO)(diag)-166
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B135) No. 8 — Chassis ground:
(B135) No. 9 — Chassis ground:
Is the resistance more than 1
MΩ?
Replace the front
oxygen (A/F) sen-
sor. FU(H6DO)-28,
Front Oxygen (A/
F) Sensor.>
Repair the ground
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.

EN(H6DO)(diag)-169
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B135) No. 8 (+) — Chassis ground (–):
(B135) No. 9 (+) — Chassis ground (–):
Is the voltage more than 8 V? Replace the front
oxygen (A/F) sen-
sor. FU(H6DO)-28,
Front Oxygen (A/
F) Sensor.>
Repair the battery
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.

EN(H6DO)(diag)-172
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 DTC using
“List of Diagnostic
Tr o u b l e C o d e
(DTC)”. EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0133.
Go to step 2.
2 CHECK EXHAUST SYSTEM.
NOTE:Check the following item.
•Loose installation of front portion of exhaust
pipe onto cylinder heads
•Loose connection between front exhaust
pipe and front catalytic converter
•Damage of exhaust pipe resulting in a hole
Is there any fault in exhaust
system?
Repair the exhaust
system.
Replace the front
oxygen (A/F) sen-
sor. FU(H6DO)-28,
Fr o nt Ox yg en ( A /
F) Sensor.>

EN(H6DO)(diag)-175
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B135) No. 8 — (E47) No. 4:
(B135) No. 9 — (E47) No. 3:
Is the resistance less than 1
Ω?
Go to step 2.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
front oxygen (A/
F) sensor con-
nector
•Poor contact
in front oxygen
(A/F) sensor
connector
•Poor contact
in ECM connec-
tor
2CHECK POOR CONTACT.
Check poor contact of front oxygen (A/F) sen-
sor connector.
Is there poor contact in front
oxygen (A/F) sensor connec-
tor?
Repair the poor
contact in front
oxygen (A/F) sen-
sor connector.
Replace the front
oxygen (A/F) sen-
sor. FU(H6DO)-28,
Fr o nt Ox yg en ( A /
F) Sensor.>

EN(H6DO)(diag)-178
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 DTC using
“List of Diagnostic
Tr o u b l e C o d e
(DTC)”. EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0137.
Go to step 2.
2CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and keep
the engine speed at 5,000 rpm.
2) Read the data of rear oxygen sensor signal
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 voltage more than 490
mV?
Go to step 5.Go to step 3.
3CHECK 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
(B135) No. 4 — (E61) No. 3:
(B135) No. 30 — (E61) No. 4:
Is the resistance more than
3Ω?
Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
Go to step 4.
4CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
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 harness connector and chassis ground.
Connector & terminal
(E61) No. 3 (+) — Chassis ground (–):
Is the voltage 0.2 — 0.5 V? Replace the rear
oxygen sensor.
FU(H6DO)-30,
Rear Oxygen Sen-
sor.>
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

EN(H6DO)(diag)-179
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
5 CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following item.
•Loose part and incomplete installation of ex-
haust system
•Damage (crack, hole etc.) of parts
•Looseness and ill fitting of parts between
front oxygen (A/F) sensor and rear oxygen sen-
sor
Is there any fault in exhaust
system?
Repair or replace
faulty par ts.
Replace the rear
oxygen sensor.
FU(H6DO)-30,
Rear Oxygen Sen-
sor.>
Step Check Yes No

EN(H6DO)(diag)-182
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 DTC using
“List of Diagnostic
Tr o u b l e C o d e
(DTC)”. EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0138.
Go to step 2.
2CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and rap-
idly reduce the engine speed from 5,000 rpm.
2) Read the data of rear oxygen sensor signal
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 voltage 250 mV or less? Go to step 5.Go to step 3.
3CHECK 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
(B135) No. 4 — (E61) No. 3:
(B135) No. 30 — (E61) No. 4:
Is the resistance more than
3Ω?
Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
Go to step 4.
4CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
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 harness connector and chassis ground.
Connector & terminal
(E61) No. 3 (+) — Chassis ground (–):
Is the voltage 0.2 — 0.5 V? Replace the rear
oxygen sensor.
FU(H6DO)-30,
Rear Oxygen Sen-
sor.>
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