data link SUBARU LEGACY 1995 Service User Guide

2. MODULE (RHD MODEL)
B2M0430A
1Engine control module (ECM)

2Data link connector (for Subaru select monitor only)

3Data link connector (for Subaru select monitor and OBD-II
general scan tool)
4Test mode connector

5CHECK ENGINE malfunction indicator lamp (MIL)
B2M0431AB2M0432A
B2M0433AOBD0008A
9
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

OBD0006C
B: OBD-II GENERAL SCAN TOOL
1. HOW TO USE OBD-II GENERAL SCAN TOOL
1) Prepare a general scan tool (OBD-II general scan tool)
required by SAE J1978.
2) Open the cover and connect the OBD-II general scan
tool to the data link connector located in the lower portion
of the instrument panel (on the driver’s side), to the lower
cover.
3) Using the OBD-II general scan tool, call up diagnostic
trouble code(s) and freeze frame data.
OBD-II general scan tool functions consist of:
(1) MODE $01: Current powertrain diagnostic data
(2) MODE $02: Powertrain freeze frame data
(3) MODE $03: Emission-related powertrain diagnostic
trouble codes
(4) MODE $04: Clear/Reset emission-related diagnos-
tic information
(5) MODE $05: Oxygen sensor monitoring test results
Read out data according to repair procedures.
(For detailed operation procedures, refer to the OBD-II
General Scan Tool Operation Manual.)
NOTE:
For details concerning diagnostic trouble codes, refer to
the DIAGNOSTIC TROUBLE CODE (DTC) LIST [T11A0].
H2M1280
2. DATA LINK CONNECTOR (FOR OBD-II GENERAL
SCAN TOOL AND SUBARU SELECT MONITOR)
1) This connector is used both for OBD-II general scan
tools and Subaru Select Monitor.
2) Terminal No. 4 to No. 6 of data link connector is used
for Subaru Select Monitor signal.
CAUTION:
Do not connect scan tools other than OBD-II general
scan tools and Subaru Select Monitor, because the
circuit for Subaru Select Monitor may be damaged.
Terminal No. Contents Terminal No. Contents
1 Power supply 9 Blank
2 Blank10 K line of ISO 9141 CARB
3 Blank11 Blank
4 Subaru Select Monitor signal (ECM to Subaru Select monitor)* 12 Ground
5 Subaru Select Monitor signal (Subaru Select monitor to ECM)* 13 Ground
6 Subaru Select Monitor clock* 14 Blank
7 Blank15 Blank
8 Blank16 Blank
*: Circuit only for Subaru Select Monitor
28
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

OBD0057A
C: SUBARU SELECT MONITOR
1. HOW TO USE SUBARU SELECT MONITOR
1) Prepare Subaru select monitor and cartridge.
ST1 498307500 SELECT MONITOR KIT
ST2 498349601 CARTRIDGE
G3M0150
2) Turn ignition switch and Subaru select monitor switch to
OFF.
3) Insert cartridge into Subaru select monitor.
OBD0059A
4) Connect Subaru select monitor to data link connector.

Using data link connector for Subaru select monitor
only, connect Subaru select monitor to its data link con-
nector located in the lower portion of the instrument
panel (on the driver’s side), to the side of the center
console box.
OBD0669A

Using data link connector for Subaru select monitor
and OBD-II general scan tool;
(1) Connect ST to Subaru select monitor cable.
ST 498357200 ADAPTER CABLE
OBD0006C
(2) Open the cover and connect Subaru select monitor
to data link connector located in the lower portion of the
instrument panel (on the driver’s side), to the lower
cover.
CAUTION:
Do not connect scan tools except for Subaru select
monitor and OBD-II general scan tool.
32
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

OBD0057A
2. SUBARU SELECT MONITOR
After performing diagnostics and clearing the memory,
check for any remaining unresolved trouble data.
1) Prepare Subaru select monitor and cartridge.
ST1 498307500 SELECT MONITOR KIT
ST2 498349601 CARTRIDGE
G3M0151
2) Turn ignition switch and monitor switch to OFF.
G3M0150
3) Insert cartridge into Subaru select monitor.
OBD0005B
4) Connect test mode connector at the lower portion of
instrument panel (on the driver’s side), to the side of the
center console box.
OBD0059A
5) Connect Subaru select monitor to data link connector.

Using data link connector for Subaru select monitor only:
Connect Subaru select monitor to its data link connector
located in the lower portion of the instrument panel (on the
driver’s side), to the side of the center console box.
60
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

OBD0669A

Using data link connector for Subaru select monitor and
OBD-II general scan tool:
(1) Connect ST to Subaru select monitor cable.
ST 498357200 ADAPTER CABLE
OBD0006C
(2) Open the cover and connect Subaru select monitor
to data link connector located in the lower portion of the
instrument panel (on the driver’s side), to the lower
cover.
CAUTION:
Do not connect scan tools except for Subaru select
monitor and OBD-II general scan tool.
OBD0060
6) Turn ignition switch ON (engine OFF) and Subaru
select monitor switch ON.
7) Start the engine.
NOTE:

Ensure the selector lever is placed in the“P”position
before starting. (AT vehicles)

Depress clutch pedal when starting the engine. (MT
vehicles)
8) Using the selector lever or shift lever, turn the“P”posi-
tion switch and the“N”position switch to ON.
9) Depress the brake pedal to turn the brake switch ON.
(AT vehicles)
10) Keep engine speed in the 2,500—3,000 rpm range
for 40 seconds.
NOTE:
On models without tachometer, use the Subaru select
monitor or tachometer (Secondary pickup type).
11) Place the selector lever or shift lever in the“D”posi-
tion (AT vehicles) or“1st”gear (MT vehicles) and drive the
vehicle at 5 to 10 km/h (3 to 6 MPH).
NOTE:

On AWD vehicles, release the parking brake.

The speed difference between front and rear wheels
may light either the ABS or the ABS/TCS warning light, but
this indicates no malfunctions. When engine control diag-
nosis is finished, perform the ABS or the ABS/TCS memory
clearance procedure of self-diagnosis system. 4-4a [T6C2] or 4-4b [T6C2] or [T9K0].>
61
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

OBD0005B
3. OBD-II GENERAL SCAN TOOL
After performing diagnostics and clearing the memory,
check for any remaining unresolved trouble data:
1) Connect test mode connector at the lower side of the
instrument panel (on the driver’s side), to the side of the
center console box.
OBD0006C
2) Open the cover and connect the OBD-II general scan
tool to its data link connector in the lower portion of the
instrument panel (on the driver’s side), to the lower cover.
CAUTION:
Do not connect the scan tools except for Subaru select
monitor and OBD-II general scan tool.
3) Start the engine.
NOTE:

Ensure the selector lever is placed in the“P”position
before starting. (AT vehicles)

Depress clutch pedal when starting the engine. (MT
vehicles)
4) Using the selector lever or shift lever, turn the“P”posi-
tion switch and the“N”position switch to ON.
5) Depress the brake pedal to turn the brake switch ON.
(AT vehicles)
6) Keep engine speed in the 2,500—3,000 rpm range for
40 seconds.
NOTE:
On models without tachometer, use the Subaru select
monitor or tachometer (Secondary pickup type).
7) Place the selector lever or shift lever in the“D”position
(AT vehicles) or“1st”gear (MT vehicles) and drive the
vehicle at 5 to 10 km/h (3 to 6 MPH).
NOTE:

On AWD vehicles, release the parking brake.

The speed difference between front and rear wheels
may light either the ABS or the ABS/TCS warning light, but
this indicates no malfunctions. When engine control diag-
nosis is finished, perform the ABS or the ABS/TCS memory
clearance procedure of self-diagnosis system. 4-4a [T6C2] or 4-4b [T6C2] or [T9K0].>
62
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

G3M0151
5. FINISHING DIAGNOSIS OPERATION
1) Disconnect test mode connector at the lower portion of
instrument panel (on the driver’s side), to the side of the
center console box.
2) Turn Subaru select monitor switch and ignition switch to
OFF.
3) Disconnect Subaru select monitor from its data link con-
nector.
64
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

ContentConnector
No.Terminal
No.Measuring conditionsVoltage
(V)Resistance to
body
(ohms)
Throttle position
sensorB54 8Throttle fully closed. 0.3—0.7
—
Throttle fully open. 4.3—4.9
Throttle position
sensor power
supplyB56 19Ignition switch ON (with engine
OFF)4.8—5.3—
ATF temperature
sensorB54 10ATF temperature 20°C(68°F) 2.9—4.0 2.1 k—2.9 k
ATF temperature 80°C (176°F) 1.0—1.4 275—375
Vehicle speed
sensor 1B54 12Vehicle stopped. 0
450—720
Vehicle speed at least 20 km/h (12
MPH)More than 1 (AC range)
Vehicle speed
sensor 2B56 11When vehicle is slowly moved at
least 2 meters (7ft).Less than 1)More than 9—
Engine speed
signalB54 5Ignition switch ON (with engine
OFF).More than 10.5
—
Ignition switch ON (with engine ON). 8—11
Cruise set signal B56 3When cruise control is set (SET
lamp ON).Less than 1
—
When cruise control is not set (SET
lamp OFF).More than 6.5
Torque control
signalB55 16 Ignition switch ON 4—6—
Torque control cut
signalB56 16 Ignition switch ON 6—9—
Mass air flow
signalB54 9 Engine idling after warm-up 0.5—1.2—
Shift solenoid 1 B55 141st or 4th gear More than 9
20—32
2nd or 3rd gear Less than 1
Shift solenoid 2 B55 131st or 2nd gear More than 9
20—32
3rd or 4th gear Less than 1
Shift solenoid 3 B55 15Selector lever in“N”range (with
throttle fully closed).Less than 1
20—32
Selector lever in“D”range (with
throttle fully closed).More than 9
Duty solenoid A B55 8Throttle fully closed (with engine
OFF) after warm-up.1.5—4.0
1.5—4.5
Throttle fully open (with engine
OFF) after warm-up.Less than 0.5
Dropping resistor B55 7Throttle fully closed (with engine
OFF) after warm-up.5—14
12—18
Throttle fully open (with engine
OFF) after warm-up.Less than 0.5
Duty solenoid B B55 5When lock up occurs. More than 8.5
9—17
When lock up is released. Less than 0.5
Duty solenoid C
(AWD model only)B55 3Fuse on FWD switch More than 8.5
9—17 Fuse removed from FWD switch
(with throttle fully open and with
select lever in 1st gear).Less than 0.5
Sensor ground
line 1B54 7—0 Less than 1
Sensor ground
line 2B56 20—0 Less than 1
System ground
lineB56 1—0 Less than 1
Power system
ground lineB55 10—0 Less than 1
FWD switch
(AWD model only)B56 2Fuse removed. 6—9.1
—
Fuse installed. Less than 1
Data link signal
(Subaru select
monitor)B5612——
—
13——
AT diagnosis
signalB56 11 Ignition switch ON Less than 1)More than 4—
72
2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

OBD0145A
B2M0271
OBD0616
1CONNECT 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.
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F08 or F47

F08: Voltage input from mass air flow sensor is shown
on display.

F47: Mass air flow is shown on display.

F08: Is sensor output equal to or more
than 0.3 V and equal to or less than
5.0 V?

F47: Is sensor output equal to or more
than 1.3 g/sec and equal to or less
than 250 g/sec?
Probable cause: Poor connect of connectors, circuit and
grounding line.
: Even if MIL lights up, the circuit has returned to a
normal condition at this time. A temporary poor
contact of the connector or harness may be the
cause. Repair harness or connector of the mass
air flow sensor.
HINT:
1Open or short circuit between mass air flow sen-
sor and ECM.

2Poor contact of connectors for mass air flow sen-
sor or ECM.
: Go to next.
: Is the value less than 0.3 V (1.3 g/sec)?
: Go to step 2.
: Go to step 5.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
138
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0690A
4CHECK HARNESS CONNECTOR BETWEEN
ECM AND MASS AIR FLOW SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness connector between
ECM and mass air flow sensor.
: Connector & terminal

1(B84) No. 26—(B3) No. 4/10Ω, or less

2(B84) No. 46—(B3) No. 3/10Ω, or less

3(B84) No. 25—(B3) No. 2/10Ω, or less
: Replace mass air flow sensor with a new one.
: Repair poor contact and open circuit of harness
between ECM and mass air flow sensor connec-
tor.
G2M0527
5
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from mass air flow sensor.
3) Connect Subaru Select Monitor or OBD-II General
Scan Tool to data link connector.
4) Turn ignition switch to ON.
5) Read data on Subaru select monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F08
: Is the value more than 5 V?
: Repair short circuit of harness between mass air
flow sensor and ECM.
: 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.
140
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code