1997 SUBARU LEGACY check engine

B2M0470C
7B1CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Turn ignition switch to ON.
: Does the MIL come on?
: Repair ground short circuit in harness between
combination meter and ECM connector.
: Replace ECM.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

C: CHECK ENGINE MALFUNCTION
INDICATOR LAMP (MIL) DOES NOT BLINK AT
A CYCLE OF 3 HZ.
DIAGNOSIS:

The CHECK ENGINE malfunction indicator lamp (MIL)
circuit is open or shorted.

Test mode connector circuit is in open.
TROUBLE SYMPTOM:

When inspection mode, MIL does not blink at a cycle of
3 Hz.
WIRING DIAGRAM:
B2M0511
B2M0470C
7C1CHECK OPERATION OF CHECK ENGINE
MALFUNCTION INDICATOR LAMP (MIL).
1) Turn ignition switch to OFF.
2) Disconnect test mode connector.
3) Turn ignition switch to ON.
: Does the MIL come on?
: Go to step7C2.
: Repair the MIL circuit.
93
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

B2M0512A
7C2
CHECK OUTPUT SIGNAL FROM ECM.
Measure voltage between test mode connector and chas-
sis ground.
: Connector & terminal
(B75) No.1 (+)—Chassis ground ():
Is voltage less than 1 V?
: Go to step7C3.
: Go to step7C4.
B2M0513A
7C3CHECK HARNESS BETWEEN ECM AND
TEST MODE CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between ECM and test
mode connector.
: Connector & terminal
(B84) No.84—(B75) No.1:
Is resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
test mode connector.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Replace ECM.
B2M0514A
7C4
CHECK GROUND CIRCUIT.
1) Turn ignition switch to OFF.
2) Measure resistance of harness between test mode con-
nector and chassis ground.
: Connector & terminal
(B76) No.1—Chassis ground:
Is resistance less than 5Ω?
: Repair poor contact in test mode connector.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between test mode and coupling
connector (B22)

Open circuit in harness between coupling connector
(B22) and engine grounding terminal

Poor contact in coupling connector (B22)
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

D: CHECK ENGINE MALFUNCTION
INDICATOR LAMP (MIL) REMAINS BLINKING
AT A CYCLE OF 3 Hz.
DIAGNOSIS:

Test mode connector circuit is shorted.
TROUBLE SYMPTOM:

Even though test mode connector is disconnected, MIL
blinks at a cycle of 3 Hz when ignition switch is turned to
ON.
WIRING DIAGRAM:
B2M0511
B2M0515A
7D1CHECK HARNESS BETWEEN ECM CON-
NECTOR AND ENGINE GROUNDING
TERMINAL.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between ECM connec-
tor and chassis ground.
: Connector & terminal
(B84) No.84—Chassis ground:
Is resistance less than 5Ω?
: Repair short circuit in harness between ECM and
test mode connector.
: Replace ECM.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

B: STARTER MOTOR CIRCUIT
WIRING DIAGRAM:
B2M1047
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

OBD0724
8B1CHECK INPUT SIGNAL FOR STARTER
MOTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from starter motor.
3) Turn ignition switch to ST.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

OBD0100A
4) Measure power supply voltage between starter motor
connector terminal and engine ground.
: Connector & terminal
(B14) No. 1 (+)—Engine ground ():
Is the voltage more than 10 V?
NOTE:

On AT vehicles, place the selector lever in the“P”or“N”
position.

On MT vehicles, depress the clutch pedal.
: Go to step8B2.
: Go to step8B3.
OBD0725
8B2CHECK GROUND CIRCUIT OF STARTER
MOTOR.
1) Turn ignition switch to OFF.
2) Disconnect terminal from starter motor.
3) Measure resistance of ground cable between ground
cable terminal and engine ground.
: Is resistance less than 5Ω?
: Check starter motor.
: Repair open circuit of ground cable.
8B3CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove SBF No. 4 from main fuse box.
3) Measure resistance of fuse.
: Is resistance less than 1Ω?
: Replace SBF No. 4.
: Go to next step 4).
4) Install SBF No. 4 to main fuse box.
5) Turn ignition switch to ON.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

OBD0103A
6) Measure power supply voltage between ignition switch
connector and chassis ground.
: Connector & terminal
(B72) No. 1 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Go to step8B4.
: Repair open circuit in harness between ignition
switch and SBF No. 4 connector.
8B4
CHECK TRANSMISSION TYPE.
: Is transmission type AT?
: Go to step8B5.
: Go to step8B9.
8B5
CHECK INHIBITOR SWITCH TYPE.
: Is inhibitor switch type plastic body?
: Go to step8B6.
: Go to step8B8.
B2M1279A
8B6
CHECK INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Place the selector lever in the“P”or“N”position.
3) Measure resistance between transmission harness
connector receptacle’s terminals.
: Connector & terminal
(T3) No. 11—No. 12:
Is the resistance less than 1Ω?
: Repair open circuit in harness between starter
motor and ignition switch connector.
: Go to step8B7.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M1280A
8B7
CHECK TRANSMISSION HARNESS.
1) Disconnect connector from inhibitor switch.
2) Measure resistance of harness between transmission
harness and inhibitor switch connector.
: Connector & terminal
(T3) No. 11—(T7) No. 2:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between transmis-
sion harness and inhibitor switch connector.
B2M1281A
: Connector & terminal
(T3) No. 12—(T7) No. 1:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between transmis-
sion harness and inhibitor switch connector.
: Is there poor contact in inhibitor switch
connector?
: Repair poor contact in inhibitor switch connector.
: Replace inhibitor switch.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure