1995 SUBARU LEGACY light

1
Pedal vibration
and noise occur
when any electric
switch is operated.Noise occurs in
body harnesses.Check that car
telephone, personal
receiver transmitter,
etc. are installed prop-
erly as required by
laws or regulations.
Check that harnesses
are routed properly.
Check that harnesses
are free from twisting
(or maintained to less
than 35-mm pitch).
Check that harnesses
are not routed too
closely to other electri-
cal units which could
serve as a source of
noise.
2
Check if vehicle
profile is correct.
(Front end of
vehicle tilts down
greater than rear
end.)Check wheel arch height
and adjust as required.
Warning light
comes on.Check using on-board
diagnosis system, accord-
ing to trouble code.
Warning light will
not go on for 1.5
seconds after igni-
tion switch is
turned on.Trouble in warning light
drive circuit. [T7A0].>
51
4-4aBRAKES
8. General Diagnostics Chart

B: EXCESSIVE STOPPING DISTANCE
Stopping distance is
too great.Snowy or sandy (low“µ”) roadsStopping distance may sometimes be longer
than for models not equipped with A.B.S.
Check if stopping
distance continues
to be excessive
when A.B.S. is inac-
tivated by discon-
necting hydraulic
control unit connec-
tor.
Ye sCheck wheels and
associated parts for
looseness.
Check tires for
improper specifica-
tions.
Check G sensor for
improper operation.
Bleed air from brake
line.
Check brake system
for abnormalities.
NoHydraulic control
unit operation
check.
[W15B0].>NoCheck hydraulic
control unit.
Ye sGo to A-1.
C: IMPROPER PEDAL OPERATION
Pedal does not
operate prop-
erly.
Long pedal
stroke
Check if brakes
operate prop-
erly.
Ye sOn A.B.S. equipped model, pedal stroke may be
slightly longer than for models which are not
equipped with A.B.S.
NoBleed air from
brake line.
Short pedal
stroke
Check if brakes
operate prop-
erly.
Ye sNormal
NoCheck if brakes
operate prop-
erly when
A.B.S. is inacti-
vated by dis-
connecting
hydraulic con-
trol unit connec-
tor.Ye sGo to A-1.
NoCheck brake
system.

52
4-4aBRAKES
8. General Diagnostics Chart

D: A.B.S. INOPERATIVE
A.B.S. does not operate.
Warning light comes on.Check using on-board diagnosis
system.
Check if abnormalities are noted
when brakes are applied at a speed
less than 10 km/h (6MPH).Normal
Except for those outlined aboveGo to A-2.
E: FREQUENT A.B.S. OPERATION
A.B.S.
operates
frequently.
Check if
brake force
is properly
distributed
to wheels.

Ye s
Faulty
A.B.S. sen-
sor systemCheck
A.B.S. sen-
sor.
Excessive front axle free play
Go to A-1.
NoCheck
brake sys-
tem.
53
4-4aBRAKES
8. General Diagnostics Chart

BRAKES
[ABS/TCS]
4-4b
Page
T DIAGNOSTICS
................................................................................2
1. Supplemental Restraint System “Airbag” ................................................2
2. Pre-inspection ..........................................................................................2
3. Electrical Components Location ..............................................................4
4. Schematic ................................................................................................6
5. Control Module I/O Signal .......................................................................7
6. Diagnostics Chart for On-board Diagnosis System...............................13
7. Diagnostics Chart for Warning Light Circuit Failure ..............................18
8. Diagnostics Chart with Trouble Code ....................................................35
9. Select Monitor Function Mode ...............................................................88
10. Diagnostics Chart with Select Monitor...................................................96
11. General Diagnostics Table ...................................................................130
12. Phenomena Peculiar to the System ....................................................131

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).
3
4-4bBRAKES
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
4
4-4bBRAKES
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
6
4-4bBRAKES
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