1996 SUBARU LEGACY warning light

B3M0257

Using oscilloscope:
(1) Install combination meter.
(2) Connect connector to TCM.
(3) Lift-up the vehicle and place safety stand.
WARNING:
On AWD models, make sure that all wheels are raised
off floor.
(4) Set oscilloscope to vehicle speed sensor 2.
Connector & terminal / No. 1—No. 2
B3M0254A
(5) Push the TCS OFF switch to ON. (With TCS mod-
els)
(6) Start the engine, and drive the wheels slowly.
(7) Measure signal voltage indicated on oscilloscope.
Specified voltage: AC 2 V, or more
NOTE:
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 AT control diagnosis is
finished, perform the ABS or the ABS/TCS memory clear-
ance procedure of self-diagnosis system.

B3M0369A
4. CHECK INPUT SIGNAL FOR TCM.
1) Connect connector to vehicle speed sensor 2.
2) Lift-up the vehicle or set the vehicle on free roller.
CAUTION:
On AWD models, raise all wheels off floor.
3) Push the TCS OFF switch to ON. (With TCS models)
4) Start the engine, and drive the wheels slowly.
5) Measure voltage between TCM and body.
Connector & terminal / Specified voltage:
(B56) No. 11—Body / Less than 1↔
more than 9 V
NOTE:
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 AT control diagnosis is
finished, perform the ABS or the ABS/TCS memory clear-
ance procedure of self-diagnosis system.

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3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
7. Diagnostic Chart with Trouble Code

OBD0145A

Using Subaru select monitor:
(1) Install combination meter.
(2) Connect connectors to TCM and vehicle speed
sensor 2.
(3) Lift-up the vehicle or set the vehicle on free roller.
(4) Turn ignition switch to OFF.
(5) Connect the Subaru select monitor to data link con-
nector.
(6) Turn ignition switch to ON and Subaru select moni-
tor switch to ON.
CAUTION:
On AWD models, raise all wheels off floor.
(7) Push the TCS OFF switch to ON. (With TCS mod-
els)
G3M0726
B3M0384
(8) Start the engine, and drive the wheels.
(9) Read data on Subaru select monitor.
(10) Designate mode using function key.
Function mode: F04 or F05
SPECIFIED DATA:
Compare speedometer with select monitor indica-
tions.

F04: Vehicle speed is indicated in mile per hour (MPH).

F05: Vehicle speed is indicated in kilometer per hour
(km/h).
NOTE:
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 AT control diagnosis is
finished, perform the ABS or the ABS/TCS memory clear-
ance procedure of self-diagnosis system.

B3M0248B

Using oscilloscope:
(1) Connect connector to vehicle speed sensor 2.
(2) Lift-up the vehicle or set the vehicle on free rollers.
CAUTION:
On AWD models, raise all wheels off floor.
(3) Set oscilloscope to TCM connector terminals.
Connector & terminals:
Positive probe; (B56) No. 11
Earth lead; Body
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3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
7. Diagnostic Chart with Trouble Code

G2M0931
(4) Push the TCS OFF switch to ON. (with TCS mod-
els)
(5) Start the engine.
(6) Shift on the gear position, and keep the vehicle
speed at constant.
(7) Measure signal voltage.
Specified voltage: 2 V, or more
NOTE:
If vehicle speed increases, the width of amplitude (W)
decreases.
NOTE:
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 AT control diagnosis is
finished, perform the ABS or the ABS/TCS memory clear-
ance procedure of self-diagnosis system.

52
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
7. Diagnostic Chart with Trouble Code

B: ELECTRICAL INSPECTION
1. WARNING LAMP ILLUMINATION PATTERN
B4M0372A
2. DISPLAY SYSTEM TYPE AND LIGHTING
CONDITIONS
: Illuminated
Mode
ABS warning
TCS warning
TCS OFF
TCS operating
Lighting conditions
Bulb checkIlluminated with IGN. ON, extinguished with E/G RUN
Illuminated with IGN. ON, extinguished after a few seconds.
Illuminated with IGN. ON, extinguished after 1 second.
ABS failureIlluminated during ABS failure (ABS and TCS functions stop)
TCS failureIlluminated during TCS failure (Only TCS functions stop)
TCS OFF
Illuminated when TCS operation is prohibited by E/G (low temperature, high
temperature, etc.); illuminated during TCS OFF conditions resulting from operation
of TCS OFF SW.
TCS operationIlluminated during TCS operation
Pad temperature warning
Illuminated when pad temperature reaches 400°C (752°F) or more when TCS is
functioning, and extinguished when temperature drops below 350°C (662°F).
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2. Pre-inspection

3. Electrical Components Location
B4M0373A
1Hydraulic control unit

2Engine control module

3AT control module

4TCS warning light

5ABS warning light

6Diagnosis connector

7TCS operating indicator light

8TCS OFF indicator light
9TCS OFF switch

10Data link connector (for Subaru select monitor)

11Data link connector (for Subaru select monitor and OBD-II
general scan tool)

12Tone wheel

13ABS sensor

14Stroke sensor

15ABS/TCS control module
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3. Electrical Components Location

4. Schematic
B4M0380A
1Hydraulic control unit

2Valve relay

3Motor relay

4Motor

5Motor sensor

6Front left inlet solenoid valve

7Front left outlet solenoid valve

8Rear right inlet solenoid valve

9Rear right outlet solenoid valve

10TCS solenoid valve 2

11Front right inlet solenoid valve

12Front right outlet solenoid valve

13Rear left inlet solenoid valve
14Rear left outlet solenoid valve

15TCS solenoid valve 1

16Pressure switch

17Data link connector

18ABS/TCS control module

19ABS warning light

20TCS operating indicator light

21TCS OFF indicator light

22TCS warning light

23Stroke sensor

24TCS OFF switch

25Diagnosis connector
26Engine control module

27Rear right ABS sensor

28Front right ABS sensor

29Front left ABS sensor

30Rear left ABS sensor

31Brake warning light

32Parking brake switch

33Brake fluid level sensor

34Generator

35Stop lamp switch

36Stop lamp

37AT control module
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4. Schematic

5. Control Module I/O Signal
1. I/O SIGNAL VOLTAGE
Contents Connector No. Terminal No.Input/Output signals
Measured value and measuring conditions
ABS
sensor
(Wheel
speed
sensor)Front left wheel P7 1—11 0.12—1 V (When it is 10 Hz.)
Front right wheel P6 8—16 0.12—1 V (When it is 10 Hz.)
Rear left wheel P6 7—15 0.12—1 V (When it is 10 Hz.)
Rear right wheel P7 2—12 0.12—1 V (When it is 10 Hz.)
Hydraulic
unitSolenoid
valveFront left outlet P4 1—GND
10—14 V when the valve is OFF.
Less than 1.5 V when the valve is ON. Front right outlet P5 3—GND
Rear left outlet P5 8—GND
Rear right outlet P4 3—GND
Front left inlet P4 2—GND
10—14 V when the valve is OFF.
Less than 1.0 V when the valve is ON. Front right inlet P5 2—GND
Rear left inlet P5 7—GND
Rear right inlet P4 4—GND
TCS 1 P4 5—GND
10—14 V when the valve is OFF.
Less than 1.0 V when the valve is ON.
TCS 2 P5 6—GND
Valve power supply P6 6—GND Ignition switch ON, 10—14 V
Valve relay power supply P6 1—GNDLess than 1.2 V when IGN is ON.
10—14 V when the system is down.
Motor relay power supply P6 9—GNDLess than 1.0 V when the motor is ON.
10—14 V when the motor is OFF.
Motor sensor signalsP7 3—GNDCyclic waveform of more than 180 Hz
when the motor across terminals is ON.
Less than 70 Hz when the motor is OFF. P7 13—GND
Pressure switch P7 6—GNDH/L toggle signal with the brake pedal off
(Cycle 14 mS, H: 10—14 V, L: less than
0.7 V). 10—14 V with the brake pedal
depressed.
Pedal
stroke
sensorOutput signals P7 5—GND 0.7—0.9 V with the brake pedal off.
Power supply P7 4—14 5±0.4 V
Stop light
switchSwitch P7 7—GNDLess than 2 V when the stop light is off.
10—12 V when the stop light is on.
Switch test signal P7 18—GNDH/L toggle signal with the brake pedal off
(Cycle 14 mS, H: 10—12 V, L: less than
0.7 V). Less than 2 V with the brake pedal
depressed.
TCS OFF switch P7 16—GNDLess than 2.0 V with the switch pressed
and 10—12 V with it released.
Indicator
lightTCS OFF P6 10—GND
Less than2Vwhenthelight is on and
10—12 V when it is off. TCS operation P6 11—GND
TCS warning P6 3—GND
ABS warning P6 2—GND
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5. Control Module I/O Signal

3. LIST OF ABS/TCS ON-BOARD DIAGNOSTICS
FUNCTIONS
Trouble codeDiagnostic items
Detection timingIndicator
light ON
Parts concerned
At initial checking
Under no control
Under ABS control
Under TCS control
In diagnostic mode
ABS warning light
TCS warning light
TCS OFF indicator light
21 FR
23 FL
25 RR
27 RLDetection of fault in ABS sensor hardware

 —ABS sensor (ABS/TCS C/M)
22 FR
24 FL
26 RR
28 RLDetection of fault in ABS sensor software
 —ABS sensor (ABS/TCS C/M)
 —ABS sensor harness circuit (ABS/TCS C/M)
Detection of fault in ABS sensor software
—ABS sensor and solenoid valve (ABS/TCS C/M)
—ABS sensor (ABS/TCS C/M)
Detection of fault in sensor software
 —ABS sensor (ABS/TCS C/M)
31 FRI
32 FRO
33 FLI
34 FLO
35 RRI
36 RRO
37 RLI
38 RLO
61 TCS1
62 TCS2Abnormal valve

*
—Solenoid valve (ABS/TCS C/M)
41 Abnormal ABS/TCS C/M
 —ABS/TCS C/M
42 Abnormal line voltage
—Power source operating environment (ABS/TCS C/M)
—Power source voltage drop
 —
—
*: Except when trouble code is being displayed.
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5. Control Module I/O Signal