2009 SUBARU TRIBECA check engine

EN(H6DO)(diag)-205
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
P0157.
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. 15 — (E25) No. 3:
(B135) No. 30 — (E25) 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
(E25) 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)-206
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)-209
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. 15 — (E25) No. 3:
(B135) No. 30 — (E25) 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
(E25) 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)-210
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)-213
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
P0159.
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
(B135) No. 15 — (E25) No. 3:
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
(B25) No. 3 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 4.Repair the chas-
sis short circuit of
harness.
4CHECK REAR OXYGEN SENSOR.
Measure the resistance between connector
terminals of rear oxygen sensor.
Te r m i n a l s
No. 3 — No. 4
Is the resistance less than 1
Ω?
Replace the rear
oxygen sensor.
FU(H6DO)-30,
Rear Oxygen Sen-
sor.>
Te m p o r a r y p o o r
contact occurs.
Check poor con-
tact of connector.

EN(H6DO)(diag)-216
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 more than 490
mV?
Go to step 6.Go to step 3.
3CHECK 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 6.Go to step 4.
4CHECK 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. 15 — (E25) No. 3:
(B135) No. 30 — (E25) 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 5.

EN(H6DO)(diag)-217
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
BA:DTC P0171 SYSTEM TOO LEAN (BANK 1)
Refer to DTC P0175 for diagnostic procedure. RICH (BANK 2), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
BB:DTC P0172 SYSTEM TOO RICH (BANK 1)
Refer to DTC P0175 for diagnostic procedure. RICH (BANK 2), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
BC:DTC P0174 SYSTEM TOO LEAN (BANK 2)
Refer to DTC P0175 for diagnostic procedure. RICH (BANK 2), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
5CHECK 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
(E25) 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
6 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)-218
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
BD:DTC P0175 SYSTEM TOO RICH (BANK 2)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION tic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
•Erroneous idling
•Engine stalls.
•Poor driving performance
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
1 CHECK EXHAUST SYSTEM.Are there holes or loose bolts
on exhaust system?
Repair the exhaust
system.
Go to step 2.
2CHECK AIR INTAKE SYSTEM.Are there holes, loose bolts or
disconnection of hose on air
intake system?
Repair the air
intake system.
Go to step 3.
3CHECK FUEL PRESSURE
WARNING:
•Place “NO FIRE” signs near the working
area.
•Be careful not to spill fuel.
Measure the fuel pressure. ME(H6DO)-26, INSPECTION, Fuel Pressure.>
WARNING:Release fuel pressure before removing the
fuel pressure gauge.
Is the measured value 338 —
348 kPa (3.4 — 3.5 kg/cm2, 49
— 50.5 psi)?
Go to step 4.Repair the follow-
ing item.
Fuel pressure is
too high:
•Clogged fuel
line or bent
hose
Fuel pressure is
too low:
•Improper fuel
pump discharge
•Clogged fuel
supply line
4CHECK ENGINE COOLANT TEMPERATURE
SENSOR.
1) Start the engine and warm-up completely.
2) Read the data of engine coolant tempera-
ture 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 engine coolant tempera-
ture above 60°C (140°F) ?
Go to step 5.Replace the
engine coolant
temperature sen-
sor. FU(H6DO)-17,
Engine Coolant
Te m p e r a t u r e S e n -
sor.>