SUBARU LEGACY 1997 Service Repair Manual

: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Replace ECM.
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0277
AF: DTC P0301
—CYLINDER 1 MISFIRE DETECTED—
OBD0278
AG: DTC P0302
—CYLINDER 2 MISFIRE DETECTED—
OBD0279
AH: DTC P0303
—CYLINDER 3 MISFIRE DETECTED—
OBD0280
AI: DTC P0304
—CYLINDER 4 MISFIRE DETECTED—
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

DTC DETECTING CONDITION:

Two consecutive driving cycles with fault

Immediately at fault recognition (A misfire which could
damage catalyst occurs.)
TROUBLE SYMPTOM:

Engine stalls.

Erroneous idling

Rough driving
WIRING DIAGRAM:
B2M1309
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
<Ref. to 2-7 [T3D0] and [T3E0].>
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10AI1CHECK DTC P0101, P0102, P0103, P0116,
P0117, P0125, P0261, P0262, P0264,
P0265, P0267, P0268, P0270 OR P0271
ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0101,
P0102, P0103, P0116, P0117, P0125, P0261,
P0262, P0264, P0265, P0267, P0268, P0270
or P0271?
: Inspect DTC P0101, P0102, P0103, P0116,
P0117, P0125, P0261, P0262, P0264, P0265,
P0267, P0268, P0270 or P0271 using“10. Diag-
nostics Chart with Trouble Code”. <Ref. to 2-7
[T10A0].>
NOTE:
In this case, it is not necessary to inspect DTC P0301,
P0302, P0303 and P0304.
: Go to step10AI2.
OBD0145A
10AI2CONNECT SUBARU SELECT MONITOR
AND READ DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor to the data link connec-
tor.
3) Turn ignition switch to ON and turn Subaru Select Moni-
tor switch to ON.
B2M0759
4) Read data on Subaru Select Monitor.
Designate mode use function key.
Function mode: F42
NOTE:
F42: Maximum and minimum EGR system pressure value
are indicated at the same time.
5) Print out the displayed data on paper.
G3M0152
6) Clear memory on Subaru Select Monitor.
Designate mode use function key.
Press [F], [C], [0], [ENT] in that order.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0008C
7) Start engine, and drive the vehicle more than 10 min-
utes.
: Is the MIL coming on or blinking?
: Go to step10AI3.
: Go to next.
: Has the vehicle been run empty of fuel?
: Finish diagnostics operation, if the engine has no
abnormality.
: Go to next.
: Was the cause of misfire diagnosed when
the engine is running?
NOTE:
Ex. Remove spark plug cord, etc.
: Finish diagnostics operation, if the engine has no
abnormality.
: Repair connector.
NOTE:
In this case, repair the following:

Poor contact in ignitor connector

Poor contact in ignition coil connector

Poor contact in fuel injector connector on faulty cylinders

Poor contact in ECM connector

Poor contact in coupling connector (B22)
10AI3
CHECK AIR INTAKE SYSTEM.
: Is there a fault in air intake system?
NOTE:
Check the following items:

Are there air leaks or air suction caused by loose or dis-
located nuts and bolts?

Are there cracks or any disconnection of hoses?
: Repair air intake system.
: Go to step10AI4.
OBD0145A
10AI4
CHECK MISFIRE SYMPTOM.
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) Turn ignition switch to ON, and turn Subaru Select
Monitor or OBD-II general scan tool switch to ON.
214
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

G3M0152
4) Read diagnostic trouble code (DTC).

Subaru Select Monitor
Designate mode use function key.
Function mode: FB1

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Operation Manual.
NOTE:
Perform diagnosis according to the items listed below.
: Does the Subaru select monitor or OBD-II
general scan tool indicate only one DTC?
: Go to step10AI5.
: Go to next.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0301 and
P0302?
: Go to step10AI6.
: Go to next.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0303 and
P0304?
: Go to step10AI7.
: Go to next.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0301 and
P0303?
: Go to step10AI8.
: Go to next.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0302 and
P0304?
: Go to step10AI9.
: Go to step10AI10.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10AI5
ONLY ONE CYLINDER
: Is there a fault in that cylinder?
NOTE:
Check the following items.

Spark plug

Spark plug cord

Fuel injector

Compression ratio
: Repair or replace faulty parts.
: Go to step10AI11.
10AI6
GROUP OF #1 AND #2 CYLINDERS
: Are there faults in #1 and #2 cylinders?
NOTE:

Check the following items.

Spark plugs

Fuel injectors

Ignition coil

If no abnormal is discovered, check for“D: IGNITION
CONTROL SYSTEM”of #1 and #2 cylinders side. <Ref. to
2-7 [T8D0].>
: Repair or replace faulty parts.
: Go to step10AI11.
216
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10AI7
GROUP OF #3 AND #4 CYLINDERS
: Are there faults in #3 and #4 cylinders?
NOTE:

Check the following items.

Spark plugs

Fuel injectors

Ignition coil

If no abnormal is discovered, check for“D: IGNITION
CONTROL SYSTEM”of #3 and #4 cylinders side. <Ref. to
2-7 [T8D0].>
: Repair or replace faulty parts.
: Go to step10AI11.
10AI8
GROUP OF #1 AND #3 CYLINDERS
: Are there faults in #1 and #3 cylinders?
NOTE:
Check the following items.

Spark plugs

Fuel injectors

Skipping timing belt teeth
: Repair or replace faulty parts.
: Go to step10AI11.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10AI9
GROUP OF #2 AND #4 CYLINDERS
: Are there faults in #2 and #4 cylinders?
NOTE:
Check the following items.

Spark plugs

Fuel injectors

Skipping timing belt teeth
: Repair or replace faulty parts.
: Go to step10AI11.
10AI10
THE CYLINDER AT RANDOM
: Is the engine idle rough?
: Go to step10AI11.
: Go to DTC P0170. <Ref. to 2-7 [T10T3], [T10T4]
and [T10T5].>
B2M0759
10AI11
CHECK EGR SYSTEM.
: Is the minimum EGR system pressure value
(value of function mode (F42) less than 1
kPa?
NOTE:
Use the value read in step10X2for function mode F42.
: Clean EGR valve.
CAUTION:
Do not use solvent when cleaning EGR valve
assembly, as it can damage diaphragm.
NOTE:

Remove and blow away the exhaust deposits. Make
sure the valve operates smoothly and the valve seat area
is completely cleaned.

Replace EGR valve as required.
: Go to DTC P0170. <Ref. to 2-7 [T10T3], [T10T4]
and [T10T5].>
218
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0283
AJ: DTC P0325
—KNOCK SENSOR CIRCUIT
MALFUNCTION—
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Poor driving performance

Knocking occurs.
WIRING DIAGRAM:
B2M1089
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
<Ref. to 2-7 [T3D0] and [T3E0].>
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles