SUBARU LEGACY 1997 Service Repair Manual

OBD0145A
10G1CONNECT 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
the OBD-II general scan tool switch to ON.
4) Start engine.
B2M0756
5) Read the data on Subaru Select Monitor or the OBD-II
general scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F21

F21: Display shows pressure signal value sent from
pressure sensor.
: Is the value more than 140 kPa in function
mode F21?
: Go to step10G4.
: Go to step10G2.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
B2M0535A
10G2CHECK INPUT SIGNAL FOR ECM.
(USING VOLTAGE METER AND SUBARU
SELECT MONITOR.)
1) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 21 (+)—Chassis ground ():
Is the voltage more than 4.5 V?
: Go to next step 2).
: Go to next.
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B2M0535A
: Does the voltage change more than 4.5 V by
shaking harness and connector of ECM
while monitoring the value with voltage
meter?
: Repair poor contact in ECM connector.
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
B2M0536A
2) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 26 (+)—Chassis ground ():
Is the voltage less than 0.2 V?
: Go to step10G3.
: Go to next step 3).
B2M0755
3) Read data on Subaru Select Monitor.

Subaru Select Monitor
Designate mode using function key.
Function mode: F20

F20: Display shows pressure signal value sent from
pressure sensor.
: Does the value change more than 0 kPa by
shaking harness and connector of ECM
while monitoring the value with Subaru
select monitor?
: Repair poor contact in ECM connector.
: Go to step10G3.
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OBD0693A
10G3CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from pressure sensor.
3) Turn ignition switch to ON.
4) Measure voltage between pressure sensor connector
and engine ground.
: Connector & terminal
(B2) No. 3 (+)—Engine ground ():
Is the voltage more than 4.5 V?
: Go to next step 5).
: Repair open circuit in harness between ECM and
pressure sensor connector.
B2M0537A
5) Turn ignition switch to OFF.
6) Disconnect connector from ECM.
7) Measure resistance of harness between ECM and pres-
sure sensor connector.
: Connector & terminal
(B84) No. 26—(B2) No. 2:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
pressure sensor connector.
: Connector & terminal
(B84) No. 20—(B2) No. 1:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
pressure sensor connector.
: Is there poor contact in pressure sensor
connector?
: Repair poor contact in pressure sensor connector.
: Replace pressure sensor.
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B2M0756
10G4CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1) Turn ignition switch to OFF and Subaru Select Monitor
or the OBD-II general scan tool switch to OFF.
2) Disconnect connector from pressure sensor.
3) Turn ignition switch to ON and Subaru Select Monitor or
the OBD-II general scan tool switch to ON.
4) Read data on Subaru select monitor or the OBD-II gen-
eral scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F21
: Is the value more than 140 kPa in function
mode F21?
: Repair battery short circuit in harness between
ECM and pressure sensor connector.
: Replace pressure sensor.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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B2M1067
H: DTC P0116
—ENGINE COOLANT TEMPERATURE
SENSOR CIRCUIT LOW INPUT—
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Hard to start

Erroneous idling

Poor driving performance
WIRING DIAGRAM:
B2M0539
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

154
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0145A
10H1CONNECT 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.
B2M0479
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F04

F04: Water temperature is indicated in“°C”and“°F”.
: Is the value greater than 150°Cor300°Fin
function mode F04?
: Go to step10H2.
: Repair poor contact.
NOTE:
In this case, repair the following:

Poor contact in engine coolant temperature sensor

Poor contact in ECM

Poor contact in coupling connector (B21)

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
OBD0618A
10H2CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove idle air control solenoid valve by-pass air hose.
3) Disconnect connector from engine coolant temperature
sensor.
OBD0145A
4) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
5) Turn ignition switch and Subaru Select Monitor or
OBD-II general scan tool switch to ON.
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B2M0479
6) Read data on Subaru Select Monitor or the OBD-II gen-
eral scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F04

F04: Water temperature is indicated in“°C”and“°F”.
: Is the value less than40°Cor40°Fin
function mode F04?
: Replace engine coolant temperature sensor.
: Repair ground short circuit in harness between
engine coolant temperature sensor and ECM con-
nector.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
156
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1068
I: DTC P0117
—ENGINE COOLANT TEMPERATURE
SENSOR CIRCUIT HIGH INPUT—
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Hard to start

Erroneous idling

Poor driving performance
WIRING DIAGRAM:
B2M0539
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

157
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10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0145A
10I1CONNECT 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.
B2M0479
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F04

F04: Water temperature is indicated in“°C”and“°F”.
: Is the value less than40°Cor40°Fin
function mode F04?
: Go to step10I3.
: Repair poor contact.
NOTE:
In this case, repair the following:

Poor contact in engine coolant temperature sensor

Poor contact in ECM

Poor contact in coupling connector (B21)

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
OBD0618A
10I2CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove idle air control solenoid valve by-pass air hose.
3) Disconnect connector from engine coolant temperature
sensor.
OBD0696A
4) Measure voltage between engine coolant temperature
sensor connector and engine ground.
: Connector & terminal
(E8) No. 1 (+)—Engine ground ():
Is the voltage more than 10 V?
: Repair battery short circuit in harness between
ECM and engine coolant temperature sensor con-
nector.
: Go to next step 5).
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OBD0696A
5) Turn ignition switch to ON.
6) Measure voltage between engine coolant temperature
sensor connector and engine ground.
: Connector & terminal
(E8) No. 1 (+)—Engine ground ():
Is the voltage more than 10 V?
: Repair battery short circuit in harness between
ECM and engine coolant temperature sensor con-
nector.
: Go to step10I3.
OBD0696A
10I3CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Measure voltage between engine coolant temperature
sensor connector and engine ground.
: Connector & terminal
(E8) No. 1 (+)—Engine 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 engine cool-
ant temperature sensor connector

Poor contact in engine coolant temperature sensor con-
nector

Poor contact in ECM connector

Poor contact in coupling connector (B21)
OBD0697A
2) Turn ignition switch to OFF.
3) Measure resistance of harness between engine coolant
temperature sensor connector and engine ground.
: Connector & terminal
(E8) No. 2—Engine ground:
Is the resistance less than 5Ω?
: Replace engine coolant temperature sensor.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and engine cool-
ant temperature sensor connector

Poor contact in engine coolant temperature sensor con-
nector

Poor contact in ECM connector

Poor contact in coupling connector (B21)
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10. Diagnostic Chart with Trouble Code for LHD Vehicles