1996 SUBARU LEGACY key

B2M0481
10B5CHECK HARNESS BETWEEN ECM AND
MASS AIR FLOW 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 mass air flow 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 OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F06
: Is the value more than 250 g/sec or5Vin
function mode F06?
: Repair short circuit in harness between mass air
flow sensor and ECM connector.
: Go to next.
: Is there poor contact in mass air flow sensor
connector?
: Repair poor contact in mass air flow sensor con-
nector.
: Replace mass air flow sensor.

OBD-II general scan tool
For detailed operation procedures, refer to OBD-II General
Scan Tool Instruction Manual.
131
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

OBD0145A
10D1CONNECT 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 less than 0 kPa in function
mode F21?
: Go to step10D2.
: Go to next.
B2M0756
: Is the value more than 140 kPa in function
mode F21?
: Go to step10D4.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open or short circuit in harness between pressure sen-
sor and ECM connector

Poor contact in pressure sensor

Poor contact in ECM connector

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
137
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

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 step10D3.
OBD0693A
10D3CHECK 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.
139
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

B2M0756
10D4CHECK 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 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.
141
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

OBD0145A
10E2
CHECK DATA FOR CONTROL.
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 ON and Subaru Select Monitor or
the OBD-II general scan tool switch ON.
4) Start engine.
B2M0756
5) 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 and F20

F21: Display shows pressure signal value sent from the
pressure sensor.

F20: Display shows pressure signal value sent from the
pressure sensor.
: Is the value more than 85 kPa in function
mode F21?
: Go to step10E3.
: Go to next.
B2M0755
: Is the value less than 32 kPa in function
mode F20?
: Go to step10E4.
: Go to next.
B2M0755
: Is the value more than 133 kPa in function
mode F20?
: Replace pressure sensor.
: Repair poor contact in pressure sensor connector,
pressure sources switching solenoid valve
connector, and ECM connector.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
145
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

OBD0145A
10F1CONNECT 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 step10F2.
: Go to next.
B2M0479
: Is the value less than40°Cor40°Fin
function mode F04?
: Go to step10F3.
: 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.
148
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

OBD0618A
10F2CHECK 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.
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 short circuit in harness between engine
coolant temperature sensor and ECM connector.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
149
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

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
OBD-II general scan tool switch to ON.
4) Start engine.
B2M0482
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F07

F07: Throttle position sensor output signal is indicated.
: Is the value less than 0.1 V in function
mode F07?
: Go to step10G2.
: Go to next.
B2M0482
: Is the value more than 4.9 V in function
mode F07?
: Go to step10G4.
: Even if MIL lights up, the circuit has returned to a
normal condition at this time. A temporary poor
contact of the connector may be the cause.
NOTE:
In this case, repair the following:

Poor contact in throttle position sensor connector

Poor contact in ECM connector

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.
153
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code