Page 1953 of 2890
OBD0240
P: DTC P0170
—FUEL TRIM MALFUNCTION (FUEL)—
DTC DETECTING CONDITION:
Two consecutive trips with fault
TROUBLE SYMPTOM:
Erroneous idling
Engine stalls.
Poor driving performance
10P1Check exhaust system.
10P2Check air intake system.
10P3Check fuel pressure.
10P4Check engine coolant temperature sensor.
10P5Check mass air flow sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODE.
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10P1
CHECK EXHAUST SYSTEM.
: Are there holes or loose bolts on exhaust
system?
: Repair exhaust system.
: Go to step10P2.
10P2
CHECK AIR INTAKE SYSTEM.
: Are there holes, loose bolts or disconnec-
tion of hose on air intake system?
: Repair air intake system.
: Go to step10P3.
G2M0340
10P3
CHECK FUEL PRESSURE.
1) Release fuel pressure.
(1) Remove fuel pump access hole lid located on the
right rear of trunk compartment floor (Sedan) or lug-
gage compartment floor (Wagon).
B2M0047
(2) Disconnect connector from fuel tank.
(3) Start the engine, and run it until it stalls.
(4) After stopping the engine, crank the engine for 5 to
7 seconds to reduce fuel pressure.
(5) Turn ignition switch to OFF.
B2M0047
2) Connect connector to fuel tank.
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OBD0711
3) Disconnect fuel delivery hose from fuel filter, and con-
nect fuel pressure gauge.
G2M0348
4) Start the engine and idle while gear position is neutral.
5) Measure fuel pressure while disconnecting pressure
regulator vacuum hose from intake manifold.
: Is fuel pressure between 226 and 275 kPa
(2.3—2.8 kg/cm2,33—40 psi)?
: Go to next step 6).
: Repair the following items.
Fuel pressure too highClogged fuel return line or bent
hose
Fuel pressure too lowImproper fuel pump discharge
Clogged fuel supply line
6) After connecting pressure regulator vacuum hose, mea-
sure fuel pressure.
: Is fuel pressure between 157 and 206 kPa
(1.6—2.1 kg/cm2,23—30 psi)?
: Go to step10P4.
: Repair the following items.
Fuel pressure too highFaulty pressure regulator
Clogged fuel return line or bent
hose
Fuel pressure too lowFaulty pressure regulator
Improper fuel pump discharge
Clogged fuel supply line
WARNING:
Before removing fuel pressure gauge, release fuel
pressure.
NOTE:
If fuel pressure does not increase, squeeze fuel return
hose 2 to 3 times, then measure fuel pressure again.
If out of specification as measured at step 6), check or
replace pressure regulator and pressure regulator vacuum
hose.
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OBD0145A
10P4CHECK ENGINE COOLANT TEMPERA-
TURE SENSOR.
1) Turn ignition switch to OFF.
2) Connect the Subaru Select Monitor or the OBD-II gen-
eral scan tool to data link connector.
3) Start the engine and warm-up completely.
B2M0479
4) Read data on Subaru Select Monitor or the OBD-II gen-
eral scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F04
F04: Water temperature is indicated in“°C”and“°F”.
: Is temperature greater than 60°Cor140°Fin
function mode F04?
: Go to step10P5.
: Replace engine coolant temperature sensor.
OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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OBD0145A
10P5
CHECK MASS AIR FLOW SENSOR.
1) Turn ignition switch to OFF.
2) Connect the Subaru Select Monitor or the OBD-II gen-
eral scan tool to data link connector.
3) Start the engine and warm-up engine until coolant tem-
perature is greater than 60°C (140°F).
4) Place the selector lever in“N”or“P”position.
5) Turn A/C switch to OFF.
6) Turn all accessory switches to OFF.
B2M0481
7) Read data on Subaru Select Monitor or OBD-II general
scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F06
F06: Mass air flow and voltage input from mass air flow
sensor are shown on display.
: Is the voltage in function mode F06 within
the specifications shown in the following
table?
Model Engine speed Specified value
2200 ccIdling 1.7—3.3 (g/sec)
2,500 rpm 7.1—14.2 (g/sec)
2500 ccIdling 2.2—4.2 (g/sec)
2,500 rpm 8.6—14.5 (g/sec)
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
: Replace mass air flow sensor.
OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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H2M1306
Q: DTC P0180
—FUEL TEMPERATURE SENSOR A CIRCUIT
MALFUNCTION (TNKT)—
DTC DETECTING CONDITION:
Immediately at fault recognition
10Q1Connect Subaru Select Monitor or the OBD-II
general scan tool, and read data.
10Q2Check harness between fuel temperature
sensor and ECM connector.
10Q3Check harness between fuel temperature
sensor and ECM connector.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
WIRING DIAGRAM:
LHD Model
B2M0916
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WIRING DIAGRAM:
RHD Model
B2M1015
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OBD0145A
10Q1CONNECT SUBARU SELECT MONITOR
OR THE OBD-II GENERAL SCAN TOOL,
AND READ DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
3) Turn ignition switch to ON and Subaru Select Monitor or
OBD-II general scan tool switch to ON.
4) Start engine.
H2M1308
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F44
F44: Fuel temperature is indicated in“°C”and“°F”.
: Is the value greater than 150°Cor300°Fin
function mode F44?
: Go to step10Q2.
: Go to next.
H2M1308
: Is the value less than 40°Cor 40°Fin
function mode F44?
: Go to step10Q3.
: Repair poor contact.
NOTE:
In this case, repair the following:
Poor contact in fuel pump connector
Poor contact in ECM connector
Poor contact in coupling connector (B22, B98 (LHD)/B97
(RHD), and R57)
OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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