SUBARU LEGACY 1996 Service Repair Manual

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.
7C1Check operation of CHECK ENGINE
malfunction indicator lamp (MIL).
7C2Check output signal from ECM.

7C3Check harness between ECM and test mode
connector.
7C4Check ground circuit.
WIRING DIAGRAM:
B2M0511


83
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

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.
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.
84
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

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)
85
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.
7D1Check harness between ECM connector and
engine grounding terminal.
WIRING DIAGRAM:
B2M0511
86
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

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.
87
2-7ON-BOARD DIAGNOSTICS II SYSTEM
7. Diagnostics for CHECK ENGINE Malfunction Indicator Lamp (MIL)

8. Diagnostics for Engine Starting
Failure
A: BASIC DIAGNOSTICS CHART
Inspection of starter motor circuit.
Inspection of ECM power supply and ground line.
Inspection of ignition control system.
Inspection of fuel pump circuit.
Inspection of fuel injector circuit.
Inspection of crankshaft position sensor circuit.
Inspection of camshaft position sensor circuit.
Inspection using Subaru select monitor or OBD-II general
scan tool or inspection using“9. General Diagnostics Table
2-7 [T900]”.







88
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B: STARTER MOTOR CIRCUIT
8B1Check input signal for starter motor.8B2Check ground circuit of starter motor.
8B3Check harness between battery and ignition
switch connector.
8B4

Check inhibitor switch. (AT vehicles only)

Check starter interlock circuit. (MT vehicles
only)
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:

LHD Model
B2M0516


89
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

WIRING DIAGRAM:

RHD Model
B2M0830
90
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

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.
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).
91
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

4) Install SBF No. 4 to main fuse box.
5) Turn ignition switch to ON.
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 harness between ignition switch and SBF
No. 4 connector.
OBD0726A
8B4
CHECK INHIBITOR SWITCH. (AT
VEHICLES ONLY)
1) Turn ignition switch to OFF.
2) Disconnect connector from transmission.
3) Measure resistance between transmission harness
connector receptacle’s terminals.
: Connector & terminal
(T3) No. 11—No. 12:
Is the resistance less than 10Ω?
: Repair harness between starter motor and ignition
switch connector.
: Repair or replace inhibitor switch.
B2M0517A
8B4
CHECK STARTER INTERLOCK CIR-
CUIT. (MT VEHICLES ONLY)
1) Turn ignition switch to“ST”.
2) Measure voltage between clutch switch connector and
chassis ground.
92
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure