Chassis SUBARU LEGACY 1997 Service Manual Online

10P1
CHECK DTC P0141 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0135 and
P0141 at the same time?
: Go to next step 1).
: Go to step10P2.
B2M0547A
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. 42—Chassis ground:
Is the resistance less than 5Ω?
: Repair poor contact in ECM connector.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and coupling con-
nector (B22)

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

Poor contact in front oxygen sensor connector

Poor contact in coupling connector (B22)
OBD0145A
10P2CONNECT 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.
B2M0497
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F32

F32: Front oxygen sensor heater current is indicated.
: Is the value more than 0.2 A in function
mode F32?
: Repair connector.
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NOTE:
In this case, repair the following:

Poor contact in front oxygen sensor connector

Poor contact in ECM connector
: Go to step10P3.

OBD-II scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
B2M0548A
10P3CHECK OUTPUT SIGNAL FROM ECM.
(USING VOLTAGE METER.)
1) Start and idle the engine.
2) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 38 (+)—Chassis ground ():
Is the voltage less than 1.0 V?
: Go to step10P4.
: Go to next.
: Does the voltage change less than 1.0 V by
shaking harness and connector of ECM
while monitoring the value with voltage
meter?
: Repair poor contact in ECM connector.
: Go to next step 3).
B2M0548A
3) Disconnect connector from front oxygen sensor.
4) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 38 (+)—Chassis ground ():
Is the voltage less than 1.0 V?
: Replace ECM.
: Repair battery short circuit in harness between
ECM and front oxygen sensor connector. After
repair, replace ECM.
B2M1075A
10P4CHECK POWER SUPPLY TO FRONT
OXYGEN SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from front oxygen sensor.
3) Turn ignition switch to ON.
4) Measure voltage between front oxygen sensor connec-
tor and engine ground.
: Connector & terminal
(B18) No. 2 (+)—Engine ground ():
Is the voltage more than 10 V?
179
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M0488
: Is the value fixed between 0.2 and 0.4 V in
function mode F13?
: Go to step10Q4.
: Replace rear oxygen sensor.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
OBD0707C
10Q4CHECK HARNESS BETWEEN REAR
OXYGEN SENSOR AND ECM CONNEC-
TOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from rear oxygen sensor.
3) Turn ignition switch to ON.
4) Measure voltage between rear oxygen sensor harness
connector and engine ground or chassis ground.
: Connector & terminal

2200 cc California spec. vehicles
(B19) No. 4 (+)—Engine ground ():

Except 2200 cc California spec. vehicles
(T6) No. 4 (+)—Chassis ground ():
Is the voltage more than 0.2 V?
: Replace rear oxygen sensor.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between rear oxygen sensor and
ECM connector

Poor contact in rear oxygen sensor connector

Poor contact in ECM connector

Poor contact in rear oxygen sensor connecting harness
connector (Except 2200 cc California spec. vehicles)
10Q5
CHECK EXHAUST SYSTEM.
: Is there a fault in exhaust system?
NOTE:
Check the following items.

Loose installation of portions

Damage (crack, hole etc.) of parts

Looseness and ill fitting of parts between front oxygen
sensor and rear oxygen sensor
: Repair or replace faulty parts.
: Replace rear oxygen sensor.
183
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

10S1
CHECK DTC P0135 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0141 and
P0135 at the same time?
: Go to next step 1).
: Go to step10S2.
B2M0553A
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. 42—Chassis ground:
Is the resistance less than 5Ω?
: Repair poor contact in ECM connector.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and coupling con-
nector (B22)

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

Poor contact in rear oxygen sensor connector

Poor contact in rear oxygen sensor connecting harness
connector (B19)

Poor contact in coupling connector (B22)
OBD0145A
10S2CONNECT 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.
B2M0498
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F33

F33: Rear oxygen sensor heater current is indicated.
: Is the value more than 0.2 A in function
mode F33?
: Repair connector.
187
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

NOTE:
In this case, repair the following:

Poor contact in rear oxygen sensor connector

Poor contact in rear oxygen sensor connecting harness
connector

Poor contact in ECM connector
: Go to step10S3.

OBD-II scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
B2M0554A
10S3CHECK OUTPUT SIGNAL FROM ECM.
(USING VOLTAGE METER.)
1) Start and idle the engine.
2) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 37 (+)—Chassis ground ():
Is the voltage less than 1.0 V?
: Go to step10S4.
: Go to next.
: Does the voltage change less than 1.0 V by
shaking harness and connector of ECM
while monitoring the value with voltage
meter?
: Repair poor contact in ECM connector.
: Go to next step 3).
B2M0554A
3) Disconnect connector from rear oxygen sensor.
4) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 37 (+)—Chassis ground ():
Is the voltage less than 1.0 V?
: Replace ECM.
: Repair battery short circuit in harness between
ECM and rear oxygen sensor connector. After
repair, replace ECM.
OBD0710C
10S4CHECK POWER SUPPLY TO REAR OXY-
GEN SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from rear oxygen sensor.
3) Turn ignition switch to ON.
4) Measure voltage between rear oxygen sensor connec-
tor and engine ground or chassis ground.
: Connector & terminal

2200 cc California spec. vehicles
(B19) No. 2 (+)—Engine ground ():
188
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

Except 2200 cc California spec. vehicles
(T6) No. 2 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Go to step10S5.
: Repair power supply line.
NOTE:
In this case, repair the following:

Open circuit in harness between main relay and rear
oxygen sensor connector

Poor contact in rear oxygen sensor connector

Poor contact in rear oxygen sensor connecting harness
connector (Except 2200 cc California spec. vehicles)
OBD0706
10S5
CHECK REAR OXYGEN SENSOR.
1) Turn ignition switch to OFF.
2) Measure resistance between rear oxygen sensor con-
nector terminals.
: Terminals
No. 1—No. 2:
Is the resistance less than 30Ω?
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between rear oxygen sensor and
ECM connector

Poor contact in rear oxygen sensor connector

Poor contact in ECM connector

Poor contact in rear oxygen sensor connecting harness
connector
: Replace rear oxygen sensor.
189
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0145A
10W1CONNECT 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.
H2M1308
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F44

F44: Fuel temperature is indicated in“°C”and“°F”.
: Is the value less than40°Cor40°Fin
function mode F44?
: Go to step10W2.
: Repair poor contact.
NOTE:
In this case, repair the following:

Poor contact in fuel pump connector

Poor contact in ECM connector

Poor contact in coupling connector (B22, B98 and R57)

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
G2M0340
10W2CHECK HARNESS BETWEEN FUEL TEM-
PERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn ignition switch to OFF.
2) Remove access hole lid.
3) Disconnect connector from fuel pump.
B2M0917A
4) Measure voltage between fuel pump connector and
chassis ground.
: Connector & terminal
(R58) No. 6 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Repair battery short circuit in harness between
ECM and fuel pump connector.
: Go to next step 5).
201
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M0917A
5) Turn ignition switch to ON.
6) Measure voltage between fuel pump connector and
chassis ground.
: Connector & terminal
(R58) No. 6 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Repair battery short circuit in harness between
ECM and fuel pump connector.
: Go to step10W3.
B2M0917A
10W3CHECK HARNESS BETWEEN FUEL TEM-
PERATURE SENSOR AND ECM CON-
NECTOR.
1) Measure voltage between fuel pump connector and
chassis ground.
: Connector & terminal
(R58) No. 6 (+)—Chassis ground ():
Is the voltage more than 4 V?
: Go to next step 2).
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and fuel pump
connector

Poor contact in fuel pump connector

Poor contact in ECM connector

Poor contact in coupling connectors (B98 and R57)
B2M0918A
2) Turn ignition switch to OFF.
3) Measure resistance of harness between fuel pump con-
nector and chassis ground.
: Connector & terminal
(R58) No. 5—Chassis ground:
Is the resistance less than 5Ω?
: Replace fuel temperature sensor.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and fuel pump
connector

Poor contact in fuel pump connector

Poor contact in ECM connector

Poor contact in coupling connectors (B22, B98 and R57)
202
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M0556A
10AA1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM connector and chassis
ground on faulty cylinders.
: Connector & terminal
#1 (B84) No. 96 (+)—Chassis ground ():
#2 (B84) No. 70 (+)—Chassis ground ():
#3 (B84) No. 44 (+)—Chassis ground ():
#4 (B84) No. 16 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Go to next.
: Go to step10AA2.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
OBD0713A
10AA2CHECK HARNESS BETWEEN FUEL
INJECTOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from fuel injector on faulty cylin-
ders.
3) Measure voltage between ECM connector and engine
ground on faulty cylinders.
: Connector & terminal
#1 (E5) No. 1—Engine ground:
#2 (E16) No. 1—Engine ground:
#3 (E6) No. 1—Engine ground:
#4 (E17) No. 1—Engine ground:
Is the resistance less than 10Ω?
: Repair ground short circuit in harness between
fuel injector and ECM connector.
: Go to next step 4).
205
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M0556A
10AE1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM connector and chassis
ground on faulty cylinders.
: Connector & terminal
#1 (B84) No. 96 (+)—Chassis ground ():
#2 (B84) No. 70 (+)—Chassis ground ():
#3 (B84) No. 44 (+)—Chassis ground ():
#4 (B84) No. 16 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Go to step10AE2.
: Go to next.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Replace ECM.
B2M0556A
10AE2CHECK HARNESS BETWEEN FUEL
INJECTOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from fuel injector on faulty cylin-
der.
3) Turn ignition switch to ON.
4) Measure voltage between ECM connector and chassis
ground on faulty cylinders.
: Connector & terminal
#1 (B84) No. 96 (+)—Chassis ground ():
#2 (B84) No. 70 (+)—Chassis ground ():
#3 (B84) No. 44 (+)—Chassis ground ():
#4 (B84) No. 16 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Repair battery short circuit in harness between
ECM and fuel injector. After repair, replace ECM.
: Go to next step 5).
G2M0464
5) Turn ignition switch to OFF.
6) Measure resistance between fuel injector terminals on
faulty cylinder.
: Terminals
No. 1—No.2:
Is the resistance less than 1Ω?
: Replace faulty fuel injector and ECM.
: Go to next.
209
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles