1997 SUBARU LEGACY check engine

B2M1279A
8B8
CHECK INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Place the selector lever in the“P”or“N”position.
3) Disconnect connector from transmission harness con-
nector.
4) 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.
: Replace inhibitor switch.
B2M0517A
8B9
CHECK STARTER INTERLOCK CIRCUIT.
1) Turn ignition switch to“ST”.
2) Measure voltage between clutch switch connector and
chassis ground.
: Connector & terminal

With cruise control
(B107) No. 2 (+)—Chassis ground ():

Without cruise control
(B106) No. 2 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Replace starter interlock relay.
: Go to next step 3).
101
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

G2M0444
8C1
CHECK MAIN RELAY.
1) Turn the ignition switch to OFF.
2) Remove main relay.
3) Connect battery to main relay terminals No. 1 and No.
2.
4) Measure resistance between main relay terminals.
: Terminals
No. 3—No. 5:
Is the resistance less than 10Ω?
: Go to next.
: Replace main relay.
: Terminals
No. 4—No. 6:
Is the resistance less than 10Ω?
: Go to step8C2.
: Replace main relay.
B2M0520A
8C2CHECK POWER SUPPLY CIRCUIT OF
ECM.
1) Install main relay.
2) Disconnect connectors from ECM.
3) Turn ignition switch to ON.
4) Measure power supply voltage between ECM connec-
tor terminals.
: Connector & terminal
(B84) No. 1 (+)—No. 19 ():
Is the voltage more than 10 V?
: Go to next.
: Repair open or ground short circuit in harness of
power supply circuit.
: Connector & terminal
(B84) No. 2 (+)—No. 19 ():
Is the voltage more than 10 V?
: Go to next.
: Repair open or ground short circuit in harness of
power supply circuit.
: Connector & terminal
(B84) No. 39 (+)—No. 19 ():
Is the voltage more than 10 V?
: Go to step8C3.
: Repair open or ground short circuit in harness of
power supply circuit.
104
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M0521A
8C3
CHECK GROUND CIRCUIT OF ECM.
1) Turn ignition switch to OFF.
2) Measure resistance of harness connector between
ECM and chassis ground.
: Connector & terminal
(B84) No. 17—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 18—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 19—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 20—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 42—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 46—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 69—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
105
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

: Connector & terminal
(B84) No. 94—Chassis ground:
Is the resistance less than 5Ω?
: Go to next.
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
: Connector & terminal
(B84) No. 95—Chassis ground:
Is the resistance less than 5Ω?
: Check ignition control system. [T8D0].>
: Repair open circuit in harness between ECM con-
nector and engine grounding terminal.
106
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

D: IGNITION CONTROL SYSTEM
WIRING DIAGRAM:
B2M0522
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

OBD0727B
B2M0644B
8D1
CHECK IGNITION SYSTEM FOR SPARKS.
1) Remove plug cord cap from each spark plug.
2) Install new spark plug on plug cord cap.
CAUTION:
Do not remove spark plug from engine.
3) Contact spark plug’s thread portion on engine.
4) While opening throttle valve fully, crank engine to check
that spark occurs at each cylinder.
: Does spark occur at each cylinder?
: Check fuel pump system. [T8F0].>
: Go to step8D2.
107
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

OBD0123A
8D2CHECK POWER SUPPLY CIRCUIT FOR
IGNITION COIL.
1) Turn ignition switch to OFF.
2) Disconnect connector from ignition coil.
3) Turn ignition switch to ON.
4) Measure power supply voltage between ignition coil
connector and engine ground.
: Connector & terminal
(E12) No. 2 (+)—Engine ground ():
Is the voltage more than 10 V?
: Go to step8D3.
: Repair open or ground short circuit in harness
between ignition coil and ignition switch connec-
tor.
OBD0124
8D3
CHECK IGNITION COIL.
1) Measure resistance between ignition coil terminals to
check primary coil.
: Terminals
No. 2—No. 1:
Is the resistance between 0.4 and 1.0Ω?
: Go to next.
: Replace ignition coil.
: Terminals
No. 2—No. 3:
Is the resistance between 0.4 and 1.0Ω?
: Replace ignition coil.
: Go to next step 2).
108
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M1050A
OBD0125B
2) Measure resistance between spark plug cord contact
portions to check secondary coil.
: Terminals
#1—#2:

2200 cc model
Is the resistance between 10 and 15 kΩ?

2500 cc model
Is the resistance between 18 and 24 kΩ?
: Go to next.
: Replace ignition coil.
: Terminals
#3—#4:

2200 cc model
Is the resistance between 10 and 15 kΩ?

2500 cc model
Is the resistance between 18 and 24 kΩ?
: Go to step8D4.
: Replace ignition coil.
OBD0126A
8D4CHECK HARNESS BETWEEN IGNITOR
AND IGNITION COIL CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ignitor.
3) Measure resistance of harness connector between igni-
tion coil and ignitor.
: Connector & terminal
(B13) No. 5—(E12) No. 1:
Is the resistance less than 1Ω?
: Go to next.
: Go to next.
: Connector & terminal
(B13) No. 6—(E12) No. 3:
Is the resistance less than 1Ω?
: Go to step8D5.
: Go to next.
: Is there poor contact in coupling connector
(B22)?
: Repair poor contact in coupling connector.
: Repair open circuit in harness between ignition
coil and ignitor connector.
109
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M1051A
B2M0224A
8D5
CHECK INPUT SIGNAL FOR IGNITOR.
Check if voltage varies synchronously with engine speed
when cranking, while monitoring voltage between ignitor
connector and engine ground.
: Connector & terminal:
(B13) No. 1 (+)—Engine ground ():
Is the voltage more than 10 V?
: Go to next.
: Replace ignitor.
: Connector & terminal:
(B13) No. 2 (+)—Engine ground ():
Is the voltage more than 10 V?
: Go to step8D6.
: Replace ignitor.
OBD0128A
8D6CHECK HARNESS OF IGNITOR GROUND
CIRCUIT.
1) Turn ignition switch to OFF.
2) Measure resistance between ignitor and engine ground.
: Connector & terminal
(B13) No. 3—Engine ground:
Is the resistance less than 5Ω?
: Go to step8D7.
: Repair open circuit in harness between ignitor
connector and engine grounding terminal.
11 0
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure