1996 SUBARU LEGACY warning

K: TROUBLE CODE 54
—FAULTY STROKE SENSOR AND/OR STOP
LIGHT SWITCH—
DIAGNOSIS:

Faulty stroke sensor

Faulty stop light switch

Faulty pump unit in hydraulic unit

Faulty ABS/TCS control module

Faulty harness/connector
TROUBLE SYMPTOM:

ABS and TCS do not operate.

No kick-back ocuurs while ABS is functioning.

Only when the stop light switch circuit is broken, the ABS
functions while TCS does not. (TCS warning light only illu-
minates.)
72
4-4bBRAKES
8. Diagnostics Chart with Trouble Code

2. FA MODE (ON/OFF DATA ARE DISPLAYED.)
If the system is in normal condition with the engine run at
idle speed (when the brake pedal is off), the LED of EC
(AEC signal) of FA2 will come on, the LED of EM (EAM
signal) blink and all other LED’s go out.
Function code
Measuring
itemsContents to be monitored Scroll Ref. to 4-4b
Code Abbreviation
FA 0OF OFF.SW LED 1 comes on with the OFF switch on.
Possible [T9H0] B1Stop light
switchLED 2 comes on with the switch on (with the brake
pedal down).
VRValve relay
signalLED 3 comes on with the valve relay off.
VMValve relay
monitorLED 4 comes on with the valve relay off.
MRMotor relay
signalLED 5 comes on with the motor on.
MS Motor sensor LED 6 comes on with the motor on.
FSFluid level
sensorLED 7 comes on with the sensor on (the fluid level
is lowered).
FA 1FI FR.IN valveLED 1 comes on when the FR.IN valve is operat-
ing.
Possible [T9I0] RO FR.OUT valveLED 2 comes on when the FR.OUT valve is operat-
ing.
FL FL.IN valve LED 3 comes on when the FL.IN valve is operating.
LO FL.OUT valveLED 4 comes on when the FL.OUT valve is operat-
ing.
T1 TCS1 valve LED 5 comes on when the TCS1 valve is operating.
RI RR.IN valveLED 6 comes on when the RR.IN valve is operat-
ing.
RO RR.OUT valveLED 7 comes on when the RR.OUT valve is operat-
ing.
RI RL.IN valve LED 8 comes on when the RL.IN valve is operating.
LO RL.OUT valveLED 9 comes on when the RL.OUT valve is operat-
ing.
T2 TCS2 valveLED 10 comes on when the TCS2 valve is operat-
ing.
FA 2AWABS warning
lightLED 1 comes on when the warning light is on.
Possible [T9J0] TWTCS warning
lightLED 2 comes on when the warning light is on.
TOTCS OFF
indicator lightLED 3 comes on when the indicator light is on.
TITCS operation
indicator lightLED 4 comes on when the indicator light is on.
EC AEC signalWith the engine run at idle speed, LED 6 (AEC)
comes on and LED 7 (AEB) goes out (They go on
and off depending on the behavior of a vehicle.) EB AEB signal
ET AET signal LED 8 comes on with the TCS control on.
EM EAM signalLED 9 comes on or blinks when the engine control
is enabled.
AT AAT signal LED 10 comes on when ABS control is on.
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4-4bBRAKES
9. Select Monitor Function Mode

LED No. Signal name Display
1Front right inlet solenoid
valveFI
2Front right outlet solenoid
valveRO
3Front left inlet solenoid
valveFI
4Front left outlet solenoid
valveLO
5Traction control solenoid
valve 1T1
6Rear right inlet solenoid
valveRI
7Rear right outlet solenoid
valveRO
8Rear left inlet solenoid
valveRI
9Rear left outlet solenoid
valveLO
10Traction control solenoid
valve 2T2
FI RO FI LO T1
RI RO RI LO T2
1
2345
678910
I: MODE FA1
—ON↔OFF SIGNAL—
Requirement for LED“ON”
LED No. 1 Front right inlet solenoid valve is in function.
LED No. 2 Front right outlet solenoid valve is in function.
LED No. 3 Front left inlet solenoid valve is in function.
LED No. 4 Front left outlet solenoid valve is in function.
LED No. 5 Traction control solenoid valve 1 is in func-
tion.
LED No. 6 Rear right inlet solenoid valve is in function.
LED No. 7 Rear right outlet solenoid valve is in function.
LED No. 8 Rear left inlet solenoid valve is in function.
LED No. 9 Rear left outlet solenoid valve is in function.
LED No. 10 Traction control solenoid valve 2 is in func-
tion.
LED No. Signal name Display
1 ABS warning light AW
2 TCS warning light TW
3 TCS OFF indicator light TO
4TCS operating indicator
lightTI
5——
6 AEC signal EC
7 AEB signal EB
8 AET signal ET
9 EAM signal EM
10 AAT signal AT
AW TW TO TI—
EC EB ET EM AT
1
2345
678910
J: MODE FA2
—ON↔OFF SIGNAL—
Requirement for LED“ON”
LED No. 1 ABS warning light is on.
LED No. 2 TCS warning light is on.
LED No. 3 TCS OFF indicator light is on.
LED No. 4 TCS operating indicator light is on.
LED No. 6 Engine is running at idle. (LED comes on or
goes off depending on vehicle movement.)
LED No. 7 Engine is running at idle. (LED comes on or
goes off depending on vehicle movement.)
LED No. 8 TCS control operates.
LED No. 9 Engine control is permitted.
LED No. 10 ABS control operates.
NOTE:
If the system is normal when idling the engine without
depressing brake pedal, LED No. 6 comes on, LED No. 9
blinks and all other LED’s are off.
91
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9. Select Monitor Function Mode

B: ELECTRICAL INSPECTION
1. WARNING LIGHT ILLUMINATION PATTERN
B4M0781A
1) When the ABS warning light does not illuminate in
accordance with this illumination pattern, there must be an
electrical malfunction.
2) When the ABS warning light remains constantly OFF,
refer to“7. Diagnostics Chart for ABS Warning Light Circuit
and Diagnosis Circuit Failure”in this section, for repair.

3
4-4cBRAKES [ABS 5.3 TYPE]
2. Pre-inspection

3. Electrical Components Location
B4M0782A
1Hydraulic control unit (H/U)

2Proportioning valve

3ABS control module (ABSCM)

4Diagnosis connector

5ABS warning light

6Data link connector (for Subaru select monitor)

7Transmission control module (only AT vehicle)
8Tone wheel

9ABS sensor

10Wheel cylinder

11G sensor (only AWD vehicle)

12Brake switch

13Master cylinder

14Relay box
4
4-4cBRAKES [ABS 5.3 TYPE]
3. Electrical Components Location

4. Schematic
B4M0787A
1Hydraulic control unit (H/U)

2Front left inlet solenoid valve

3Front left outlet solenoid valve

4Front right inlet solenoid valve

5Front right outlet solenoid valve

6Rear left inlet solenoid valve

7Rear left outlet solenoid valve

8Rear right inlet solenoid valve

9Rear right outlet solenoid valve

10Motor

11Transmission control module (only AT model)

12ABS warning light

13Motor relay
14Valve relay

15Relay box

16Data link connector

17Diagnosis connector

18Stop light switch

19Stop light

20G sensor (only AWD model)

21Front left ABS sensor

22Front right ABS sensor

23Rear left ABS sensor

24Rear right ABS sensor

25ABS control module (ABSCM)
6
4-4cBRAKES [ABS 5.3 TYPE]
4. Schematic

Contents Terminal No.Input/Output signal
Measured value and measuring conditions
ABS sensor
(Wheel
speed
sensor)Front left wheel 49—19
0.12—1V
(When it is 20 Hz.) Front right wheel 14—15
Rear left wheel 16—17
Rear right wheel 18—46
Hydraulic
control unitSolenoid
valveFront left outlet 51—1
10—13 V when the valve is OFF and
less than 1.5 V when the valve is ON. Front right outlet 3—1
Rear left outlet 4—1
Rear right outlet 50—1
Front left inlet 24—1
Front right inlet 30—1
Rear left inlet 31—1
Rear right inlet 23—1
Relay boxValve relay power supply 27—110—13 V when ignition switch is ON.
Valve relay coil 47—1 Less than 1.5 V when ignition switch is ON.
Motor relay coil 22—1More than 10 V when the ABS control does not operate still
and less than 1.5 V when ABS operates.
Motor monitoring 10—1Less than 1.5 V when the ABS control does not operate still
and more than 10 V when ABS operates.
G sensor
(AWD
model only)power supply 8—45 4.75—5.25 V
ground 45—
output 7—45 2.3±0.2 V when vehicle is in horizontal position.
Stop light switch 36—1Less than 1.5 V when the stop light is OFF and more than
4.5 V when the stop light is ON.
ABS warning light 54—1Less than 1.5 V during 1.5 seconds when ignition switch is
ON, and 10—14 V after 1.5 seconds.
AT ABS signal
(AT model only)12—1Less than 1.5 V when the ABS control does not operate still
and more than 5.5 V when ABS operates.
ABS operation signal monitor 39—1Less than 1.5 V when the ABS control does not operate still
and more than 5.5 V when ABS operates.
Select
monitorData is received. 11—1 Less than 1.5 V when no data is received.
Data is sent. 38—1 4.75—5.25 V when no data is sent.
Diagnosis
connectorTerminal No. 3 5—110—14 V when ignition switch is ON.
Terminal No. 6 13—110—14 V when ignition switch is ON.
Power supply 28—110—14 V when ignition switch is ON.
Grounding line 1—
Grounding line 55—
8
4-4cBRAKES [ABS 5.3 TYPE]
5. Control Module I/O Signal

6. Diagnostics Chart for On-board
Diagnosis System
A: BASIC DIAGNOSTICS PROCEDURE
TROUBLE OCCURS.
Is Select Monitor available?
No
Ye s
10. Diagnostic Chart with Select
Monitor
Ask the customer when and how the
trouble occurred using interview
check list.
PRE-INSPECTION

CALLING UP A TROUBLE CODE.
No trouble code is readable.

Inspection using Diagnostic Chart for
Warning Light Failure.

Record all trouble codes.
Trouble codes
are issued.
Only the start code is issued.
Inspection using General Diagnostics
Chart

Perform diagnostics in accordance with trouble code.

Trouble code
designated.

Repair.
Clear memory.

INSPECTION MODE

CALLING UP A TROUBLE CODE.

Only the start code is issued.
CONFIRMATION TEST
END
NOTE:

To check harness for broken wires or short circuits,
shake it while holding it or the connector.

When ABS warning light illuminates, read and record
trouble code indicated by ABS warning light.












10
4-4cBRAKES [ABS 5.3 TYPE]
6. Diagnostics Chart for On-board Diagnosis System