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OBD0240
T: DTC P0170
—FUEL TRIM MALFUNCTION—
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Erroneous idling
Engine stalls.
Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODE.
10T1
CHECK EXHAUST SYSTEM.
: Are there holes or loose bolts on exhaust
system?
: Repair exhaust system.
: Go to step10T2.
10T2
CHECK AIR INTAKE SYSTEM.
: Are there holes, loose bolts or disconnec-
tion of hose on air intake system?
: Repair air intake system.
: Go to step10T3.
G2M0340
10T3
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).
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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.
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
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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 step10T4.
: 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 this step, check or
replace pressure regulator and pressure regulator vacuum
hose.
OBD0145A
10T4CHECK ENGINE COOLANT TEMPERA-
TURE SENSOR.
DTC P0117 [T10I0].>
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.
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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 step10T5.
: 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.
OBD0145A
10T5
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.
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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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H2M1350
U: DTC P0181
—FUEL TEMPERATURE SENSOR A CIRCUIT
RANGE/PERFORMANCE PROBLEM—
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
WIRING DIAGRAM:
B2M0916
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
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10U1CHECK DTC P0182 OR P0183 ON DIS-
PLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0182 or
P0183?
: Inspect DTC P0182 or P0183 using“10. Diagnos-
tics Chart with Trouble Code”.
[T10A0].>
NOTE:
In this case, it is not necessary to inspect DTC P0181.
: Replace fuel temperature sensor.
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B2M1079
V: DTC P0182
—FUEL TEMPERATURE SENSOR A CIRCUIT
LOW INPUT—
DTC DETECTING CONDITION:
Immediately at fault recognition
WIRING DIAGRAM:
B2M0916
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
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