check engine light SUBARU LEGACY 1995 Service User Guide

G4M0744
2. AIR TIGHTNESS CHECK
Start engine, and run it for 1 to 2 minutes, then turn it off.
Depress brake pedal several times applying the same
pedal force as that used in ordinary braking operations.
The pedal stroke should be greatest on the 1st depression,
and it should become smaller with each successive
depression. If no change occurs in the pedal height while
in a depressed state, brake booster is faulty.
NOTE:

In the event of defective operation, inspect the condition
of the check valve and vacuum hose.

Replace them if faulty and conduct the test again.

If no improvement is observed, check precisely with
gauges.
G4M0914
3. OPERATION CHECK
1) With engine off, depress brake pedal several times
applying the same pedal force and make sure that the
pedal height does not vary with each depression of the
pedal.
2) With brake pedal depressed, start engine.
3) As engine starts, brake pedal should move slightly
toward the floor. If no change occurs in the pedal height,
brake booster is faulty.
NOTE:
If faulty, check precisely with gauges.
4. LOADED AIR TIGHTNESS CHECK
Depress brake pedal while engine is running, and turn off
engine while the pedal is still depressed. Keep the pedal
depressed for 30 seconds; if no change occurs in the pedal
height, brake booster is functioning normally; if the pedal
height increases, it is faulty.
NOTE:
If faulty, check precisely with gauges.
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4-4SERVICE PROCEDURE
6. Brake Booster

2. CHECKING THE HYDRAULIC UNIT OPERATION BY
PRESSURE GAUGE
1) Remove the FL and FR pipes from the hydraulic unit.
G4M0460
2) Connect two pressure gauges to the hydraulic unit.
CAUTION:

Pressure gauges used exclusively for brake fluid
must be used.

Do not employ pressure gauge previously used for
transmission since the piston seal is expanded which
may lead to malfunction of the brake.
3) Bleed air from the pressure gauges.
4) Perform sequence control.
B4M0082A
(1) Connect diagnosis terminals to 3 terminals (K) and
6 terminals (L) of the diagnosis connector beside driver
seat heater unit.
(2) Turn ignition switch ON.
(3) The ABS warning light comes on.
(4) Depress the brake pedal within 0.5 seconds after
the warning light goes out so that the pressure gauge
registers a pressure equal to the initial value.
CAUTION:
Do not depress the clutch pedal.
NOTE:
The engine must not be operating.
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4-4SERVICE PROCEDURE
15. Hydraulic Unit for ABS System

G4M0462
3. CHECKING THE HYDRAULIC UNIT WITH BRAKE
TESTER
1) In the case of AWD vehicles, install a spare fuse with
the FWD connector in the engine compartment to simulate
FWD vehicles.
B4M0082A
2) Connect diagnosis terminals to 3 terminals (K) and 6
terminals (L) of the diagnosis connector beside driver seat
heater unit.
G4M0464
3) Set the front wheels or rear wheels on the brake tester
and set the select lever’s position at“neutral”.
4) Operate the brake tester.
5) Perform sequence control.
(1) Turn ignition switch ON.
(2) The ABS warning light comes on.
(3) Depress the brake pedal within 0.5 seconds after
the warning light goes out so that the brake tester reg-
isters a pressure equal to the initial value.
CAUTION:
Do not depress the clutch pedal.
NOTE:
The engine must not be operating.
6) Hydraulic unit begins to work; and check the following
working sequence.
(1) The left front wheel performs decompression,
holding, and compression in sequence, and subse-
quently the right front wheel repeats the cycle.
(2) Simultaneously both right and left rear wheel per-
form decompression, holding, and compression in
sequence.
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4-4SERVICE PROCEDURE
15. Hydraulic Unit for ABS System

G4M0436
16) Check the pedal stroke.
While the engine is idling, depress the brake pedal with a
490 N (50 kg, 110 lb) load and measure the distance
between the brake pedal and steering wheel. With the
brake pedal released, measure the distance between the
pedal and steering wheel again. The difference between
the two measurements must be less than specified.
Specified pedal stroke:
With TCS
95 mm (3.74 in)
When depressing brake pedal with a 490 N (50 kg,
110 lb) load.
If the distance is more than specifications, there is a
possibility that air is in the brake line. Bleed air from the
brake line.
17) Turn ignition switch OFF.
18) Disconnect select monitor or diagnosis terminal.
19) Add brake fluid to the required level (MAX. level) of
reserve tank.
20) As a final step, test run the vehicle at low speed and
apply brakes relatively hard 2 to 3 times to ensure that
brakes provide normal braking action on all four wheels
without dragging and uneven braking.
2. CONDITIONS FOR AIR BLEEDING CONTROL
Stop light
switchTCS OFF
switchPump
motorTCS
valveFRO
RLOFLO
RROTCS
operating
indicator
lightABS
warning
lightTCS
warning
light
Air
bleeding
control is
operating.OFF ON ON Close Close Close ON ON ON
ON ON OFF Open Open Close ON ON OFF
ON ON OFF Open Close Open ON OFF ON
ON or OFF OFF OFF Open Close Close ON OFF OFF
Stops tem-
porarily.*——OFF Open Close Close OFF OFF OFF
Prohibited.——OFF Open Close Close OFF ON ON
*: When brake fluid level switch detects brake fluid in LOW level, control operation stops temporarily. After refilling brake fluid, operation
re-starts.
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4-4SERVICE PROCEDURE
19. Air Bleeding (With TCS model)

D: ABS SEQUENCE CONTROL
1) Under the ABS sequence control, after the hydraulic
unit solenoid valve is driven, the operation of the hydraulic
unit can be checked by means of the brake tester or pres-
sure gauge.
2) ABS sequence control can be started by diagnosis con-
nector or select monitor.
B4M0082C
1. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminal No. 4 of the
diagnosis connector beside driver’s seat heater unit.
2) Ignition switch is turned to ON.
3) Make sure only the start code (code 11) is shown in
normal condition.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
4) Set the speed of all wheels at 10 km/h (6 MPH) or less.
5) Turn ignition switch OFF.
6) Within 0.5 seconds after the ABS and TCS warning
lights go out, depress the brake pedal and hold it immedi-
ately after engine starts.
NOTE:

When the ignition switch is set to on, the brake pedal
must not be depressed.

Engine must operate.

If brake pedal is not depressed within 0.5 seconds after
ABS and TCS warning lights go out, the trouble code mode
comes on.
7) After completion of ABS sequence control, turn ignition
switch OFF.
2. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH SELECT MONITOR
1) Connect select monitor to data link connector beside
driver’s seat heater unit.
2) Engine starts.
3) Put select monitor to TCS mode.
4) put select monitor to FBI mode. Make sure code 11 is
indicated.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
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4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

F: TCS SEQUENCE CONTROL
1) Under the TCS sequence control, after the hydraulic
unit solenoid valve is driven, the operation of the hydraulic
unit can be checked by means of the brake tester or pres-
sure gauge.
2) TCS sequence control can be started by diagnosis con-
nector or select monitor.
B4M0082C
1. OPERATIONAL GUIDELINES OF THE TCS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminal No. 4 of the
diagnosis connector beside driver seat heater unit.
2) Ignition switch is turned to ON.
3) Make sure only the start code (code 11) is shown in
normal condition.
NOTE:
When trouble codes are stored in memory, repair the faulty
parts.
4) Set the speed of all wheels at 10 km/h (6 MPH) or less.
5) Turn ignition switch OFF.
6) Start engine, and within 0.5 seconds after the ABS
warning light and TCS warning light go out, press TCS OFF
switch. Within 1.0 second thereafter, release and press the
switch again. Then, keep the switch pressed.
NOTE:

When the TCS sequence control is set to on, the brake
pedal must not be depressed.

Engine must operate.

When TCS OFF switch is not depressed within 0.5 sec-
onds after ABS and TCS warning lights turn off, the trouble
code mode comes on.
7) After completion of TCS sequence control, turn ignition
switch OFF.
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4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

G4M0612
4. LEAK TEST — HIGH-PRESSURE SIDE
Operate the A/C system for approx. 10 minutes, then turn
the engine off and begin the leak test.
1) Begin at the connection of the high-pressure tube to the
evaporator, and work your way along the high- pressure
side of the system to the compressor. There are three
places to check on each tube connection.
2) Check the area.
(1) Check the area where the fitting joins the tube.
G4M0613
(2) Check the area where the two parts of the fitting
join each other.
G4M0614
(3) Check the area where the nut joins the tube.
3) Check the area of the sight glass and pressure switch
(dual switch), and also check the seams of the receiver
drier.
4) Check the connections of the tubes to the condenser,
and also check any welded joints on the condenser.
CAUTION:
An oily area on the fins of the condenser may indicate
a leak.
5) Check the area where the hoses attach to the compres-
sor.
6) Check around the machined portions of the compressor
(where the compressor sections join each other).
7) If equipped, check the thermal limiter on the compres-
sor housing.
8) Check the compressor shaft seal by probing near the
center of the compressor clutch pulley.
NOTE:
Some shaft seals have a very slight amount of normal
leakage [approximately 28 g (1.0 oz) per year].
24
4-7SERVICE PROCEDURE
8. Leak Testing

9. Sight Glass Inspection
1. INSPECTION CONDITION
1) Operate the engine at approximately 1,500 rpm.
2) Open the door windows.
3) Set the fan switch to the 4th (High) position.
4) Set the mode selector switch to“A/C”position.
5) Set the temperature control switch to Full cold position.
6) Ensure that compressor discharge pressure is at least
588 kPa (6 kg/cm
2, 85 psi).
NOTE:
When discharge pressure does not reach 588 kPa (6
kg/cm
2, 85 psi) in areas where outside air temperature is
low, proceed as follows:
a. Set the TEMP. SWITCH to the Full hot position.
b. Set the temperature control switch to“MAX. A/C”posi-
tion.
c. Close the door windows completely.
d. Increase the compartment temperature so that dis-
charge pressure reaches at least 588 kPa (6 kg/cm
2,85
psi).
2. REFRIGERANT CHARGE AMOUNT CHECKING
Check the refrigerant charge amount using the following
table as a guide.
Item to check Adequate Insufficient Almost in refrigerant Too much refrigerant
State in sight glassCLEAR
Air bubbles sometimes
appear when engine
speed is increased or
decreased.
G4M0669
FOAMY or BUBBLY
Air bubbles always
appear.
G4M0670
FROSTY
Frost-like appears.
G4M0671
NO FOAM
No air bubbles appear.
G4M0672
Temperature of high
and low pressure linesHigh-pressure side is
hot while low-pressure
side is cold. (A big
temperature difference
between high and low
pressure side)High-pressure side is
warm and low-pressure
side is slightly cold.
(Not so big temperature
difference between high
and low pressure side)There is almost no
temperature difference
between high and low
pressure side.High-pressure side is
hot and low-pressure
side is slightly warm.
(Slight temperature
difference between high
and low pressure side)
Pressure of systemBoth pressures on high
and low pressure sides
are normal.Both pressures on high
and low pressure sides
are slightly low.High-pressure side is
abnormally low.Both pressures on high
and low pressure sides
are abnormally high.
54
4-7DIAGNOSTICS
9. Sight Glass Inspection

3. Spark Plug
A: REMOVAL AND INSTALLATION
CAUTION:
All spark plugs installed on an engine, must be of the
same heat range.
Spark plug:
CHAMPION: RC10YC4
(Alternate)
NGK: BKR6E-11
NIPPONDENSO: K20PR-U11
1) Remove spark plug cords by pulling boot, not cord itself.
2) Remove spark plugs.
3) When installing spark plugs on cylinder head, use spark
plug wrench.
Tightening torque (Spark plug):
20.6±2.9 N⋅m (2.10±0.30 kg-m, 15.19±2.14 ft-lb)
CAUTION:
The above torque should be only applied to new spark
plugs without oil on their threads.
In case their threads are lubricated, the torque should
be reduced by approximately 1/3 of the specified
torque in order to avoid their over-stressing.
4) Connect spark plug cords.
G6M0086
B: INSPECTION
Check electrodes and inner and outer porcelain of plugs,
noting the type of deposits and the degree of electrode
erosion.
G6M0087
1) Normal
Brown to grayish-tan deposits and slight electrode wear
indicate correct spark plug heat range.
22
6-1SERVICE PROCEDURE
3. Spark Plug

2. Generator
Turn ignition switch ON
(engine OFF).
Check if charge bulb
comes on.
YES
NO
Disconnect generator
body harness
connector.
Turn ignition switch to
“START.”(engine starts.)Check if charge bulb
comes on when terminal
(L) of body harness
connector is grounded.
YES
NO
Replace charge bulb.
Check IC regulator.
Check positive terminal
of diode.
Check if charge bulb is
OFF while engine idles.
NO
YES (Remains ON or blinks.)
Check or replace fan belt.
Check generator.
Check S or BAT terminal for improper
contact.
Measure VB* of battery
while running engine at
1,500 rpm.15.5 V is less than VB.
Replace IC regulator
assembly.
VB is less
than 12.5 V.12.5 V is less than or equal to VB, and
VB is less than or equal to 15.5 V.
Check IC regulator as a
single unit.
Turn light switch ON
while engine idles.Check if charge bulb
comes on.
YES
NO
No problems
Check diode assembly.
*: Terminal voltage







26
6-1DIAGNOSTICS
2. Generator