check engine SUBARU LEGACY 1995 Service Repair Manual

OBD0145A
1CONNECT 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.
OBD0215
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F29

F29: Front oxygen sensor heater current is indicated.
: Is the reading of F29 0.2 A, or more?
: Go to step 2.
: Repair connector.
NOTE:
In this case, poor contact in front oxygen sensor connec-
tor and ECM connector can be the possible cause.

OBD-II scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
OBD0216A
2CHECK OUTPUT SIGNAL FROM ECM. (USING
VOLTAGE METER.)
1) Start and idle the engine.
2) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 44—Body/1.0 V, or less
: Go to step 3.
: Go to next.
: Is the voltage less than 1.0 V while shaking
harness and connector of ECM?
: Repair poor contact in ECM connector.
: Go to next step.
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1
CHECK DTC P0130 ON DISPLAY.
: Check that Subaru Select Monitor or the
OBD-II general scan tool shows P0130.
: Go to step 2.
: Go to step 3.
2
CHECK FAILURE CAUSE OF P0130.
Perform the step 1 of DTC P0130.
: Is the failure cause of P0130 in the fuel sys-
tem?
: Check fuel system. In this case, inspection of
P0136 is not necessary.
: Go to step 3.
OBD0145A
3
CHECK REAR OXYGEN SENSOR DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor or OBD-II general scan
tool to data link connector.
3) Start the engine, and turn Subaru Select Monitor or
OBD-II general scan tool switch to ON.
4) Warm-up the engine until engine coolant temperature is
above 70°C (160°F), and keep the engine speed at 2,000
rpm to 3,000 rpm for two minutes.
OBD0225
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F16

F16: Rear oxygen sensor output signal is indicated.
: Is the indicated data fluctuate?
: Go to step 5.
: Go to next.
: Is the indicated data fixed at 0.3±0.1 V?
: Go to step 4.
: Replace rear oxygen 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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11. Diagnostics Chart with Trouble Code

OBD0145A
1CONNECT 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.
OBD0708
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F30

F30: Rear oxygen sensor heater current is indicated.
: Is the reading of F30 0.2 A, or more?
: Go to step 2.
: Repair connector.
NOTE:
In this case, poor contact of rear oxygen sensor connector
and ECM connector can be the possible cause.

OBD-II scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
OBD0709A
2CHECK OUTPUT SIGNAL FROM ECM. (USING
VOLTAGE METER.)
1) Start and idle the engine.
2) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 43—Body/1.0 V, or less
: Go to step 3.
: Go to next.
: Is the voltage less than 1.0 V while shaking
harness and connector of ECM?
: Repair poor contact in ECM connector.
: Go to next step.
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11. Diagnostics Chart with Trouble Code

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
1.Check exhaust system.
2.Check air intake system.
3.Check fuel pressure.
4.Check engine coolant temperature sensor.

5.Check mass air flow sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODE. [T3D0] and [T3E0].>




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11. Diagnostics Chart with Trouble Code

1
CHECK EXHAUST SYSTEM.
: Are there holes or loose bolts on exhaust
system?
: Repair exhaust system.
: Go to step 2.
2
CHECK AIR INTAKE SYSTEM.
: Are there holes, loose bolts or disconnec-
tion of hose on air intake system?
: Repair air intake system.
: Go to step 3.
B2M0047
3
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).
(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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11. Diagnostics Chart with Trouble Code

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.
: Fuel pressure:
226—275 kPa (2.3—2.8 kg/cm2,
33—40 psi)
: Go to next step.
: Repair the following items.
Fuel pressure too high
Clogged fuel return line or bent
hose
Fuel pressure too low
Improper fuel pump discharge

Clogged fuel supply line
6) After connecting pressure regulator vacuum hose, mea-
sure fuel pressure.
: Fuel pressure:
157—206 kPa (1.6—2.1 kg/cm2,
23—30 psi)
: Go to step 4.
: Repair the following items.
Fuel pressure too high
Faulty pressure regulator

Clogged fuel return line or bent
hose
Fuel pressure too low
Faulty 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.
200
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11. Diagnostics Chart with Trouble Code

4CHECK ENGINE COOLANT TEMPERATURE
SENSOR.
< REF. TO“F: DTC P0115 [T11F0].”>
1) Turn ignition switch to OFF.
OBD0145A
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.
OBD0176
OBD0177
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: F05 or F06

F05: Water temperature is indicated in“°F”.

F06: Water temperature is indicated in“°C”.
: Is temperature indicated on Subaru Select
Monitor (F05) greater than 140°F?
Is temperature indicated on Subaru Select
Monitor (F06) greater than 60°C?
: Go to step 5.
: 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.
201
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11. Diagnostics Chart with Trouble Code

OBD0145A
5
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).
OBD0616
4) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F47

F47: Mass air flow is shown on display.
: Is the voltage within the specifications
shown in the following table?
Engine speed Specified value
Idling 1.9—3.6 (g/sec)
2,500 rpm 7.0—14.8 (g/sec)
: Replace mass air flow sensor.
: Contact with SOA service.
Note: Inspection by DTM is required.
Probable cause: Deterioration of plural parts

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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11. Diagnostics Chart with Trouble Code

OBD0627
7) Read data on Subaru Select Monitor.
Designate mode use function key.
Function mode: F33, F34, F35 and F36
: Is the maximum misfire rate of each cylin-
der less than 2 %?
: Go to next.
: Go to step 3.
: The vehicle has been empty of fuel.
:
The engine has no abnormality.

Finish diagnostics operation.
: Go to next.
: Check if the cause of misfire was made
when the engine is running.
Ex. Remove spark plug cord, etc.
:
The engine has no abnormality.

Finish diagnostics operation.
: Repair poor contact in ignitor, ignition coil, fuel
injector, ECM and coupling harness connector.
3
CHECK AIR INTAKE SYSTEM.
: Check the following items.

1Are there air leaks or air suction caused
by loose or dislocated nuts and bolts?

2Are there cracks or any disconnection of
hoses?
: Repair air intake system.
: Go to step 4.
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11. Diagnostics Chart with Trouble Code

5GROUP OF #2 AND #4 CYLINDERS
: Check the following items for #2 and #4 cyl-
inders.

Spark plugs

Fuel injectors

Skipping timing belt teeth

6THE CYLINDER AT RANDOM
: Is the engine idle rough?
: Go to next. (AT models only)
: Go to DTC P0170 [T11P3], [T11P4] and [T11P5].
NOTE:
On MT models, go to DTC P0170 [T11P3], [T11P4] and
[T11P5].
OBD0631
OBD0632
: Is the differential pressure between maxi-
mum EGR system pressure (value of func-
tion mode F37) and minimum EGR system
pressure (value of function mode F38) less
than 10 mmHg?
NOTE:
Use the values read in step 3 for function modes F37 and
F38.
: Replace EGR valve.
: Go to DTC P0170 [T11P3], [T11P4] and [T11P5].
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11. Diagnostics Chart with Trouble Code