SUBARU LEGACY 1997 Service Repair Manual

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.
B4M0082D
1. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR
1) Connect diagnosis terminals to terminals No. 3 and No.
6 of the diagnosis connector beside driver’s seat heater
unit.
2) Set the speed of all wheels at 4 km/h (2 MPH) or less.
3) Turn ignition switch OFF.
4) Within 0.5 seconds after the ABS warning light goes
out, depress the brake pedal and hold it immediately after
ignition switch is turned to ON.
CAUTION:
Do not depress the clutch pedal.
NOTE:

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

Engine must not operate.
5) After completion of ABS sequence control, turn ignition
switch OFF.
2. OPERATIONAL GUIDELINES OF THE ABS
SEQUENCE CONTROL WITH SELECT MONITOR
NOTE:
In the event of any trouble, the sequence control may not
be operative. In such a case, activate the sequence
control, referring to“OPERATIONAL GUIDELINES OF
THE ABS SEQUENCE CONTROL WITH DIAGNOSIS
CONNECTOR”. <Ref. to 4-4 [W22D1].>
1) Connect select monitor to data link connector beside
driver’s seat heater unit.
2) Turn ignition switch ON.
3) Put select monitor to ABS mode.
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4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

B4M0635
4) PressFD1ENTkey.
B4M0997
5) The message shown in the figure is displayed.
B4M0998
6) The message shown in the figure is displayed as fol-
lows:
(1) When using the brake tester, depress brake pedal
with braking force of 981 N (100 kg, 221 lb).
(2) When using the pressure gauge, depress brake
pedal so as to make the pressure gauge indicate 3,432
kPa (35 kg/cm
2, 498 psi).
CAUTION:
Do not depress the clutch pedal.
B4M0999
7) When the message shown in the figure is displayed,
press ENT key.
8) Check points will be displayed on select monitor.
B4M1000
9) When ABS sequence control cannot be started (by sys-
tem malfunction, etc.), the message shown in the figure will
be displayed.
NOTE:
Read the trouble codes. Repair faulty parts.
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4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

B4M1030
10) After completion of ABS sequence control.
H4M1144
11) Press 0 key to start ABS sequence control again and
press 1 key to end.
3. CONDITIONS FOR COMPLETION OF ABS
SEQUENCE CONTROL
When the following conditions develop, the ABS sequence
control stops and ABS operation is returned to the normal
control mode.
1) When the speed of at least one wheel reaches 10 km/h
(6 MPH).
2) When terminal No. 3 or No. 6 are separated from diag-
nosis terminals. (When select monitor is not used.)
3) When the brake pedal is released during sequence con-
trol and the braking lamp switch is set to off.
4) When brake pedal is depressed after ignition key is
turned to ON, and before ABS warning light goes out.
(When select monitor is not used.)
5) When brake pedal is not depressed after ignition key is
turned to ON, and within 0.5 seconds after ABS warning
light goes out. (When select monitor is not used.)
6) After completion of the sequence control.
7) When malfunction is detected. (When select monitor is
used.)
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4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

4. CONDITIONS FOR ABS SEQUENCE CONTROL
B4M1001A
NOTE:

When select monitor is used, control operation starts at
point A. The patterns from IGN key ON to the point A show
that operation is started by diagnosis connector.

HIGH means high voltage.

LOW means low voltage.
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4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

B4M1222
E: INSTALLATION
1) Install ABSCM&H/U.
CAUTION:
Confirm that the specifications of the ABSCM&H/U
conforms to the vehicle specifications.
Tightening torque:
18±5 N⋅m (1.8±0.5 kg-m, 13.0±3.6 ft-lb)
2) Connect brake pipes to their correct ABSCM&H/U con-
nections. <Ref. to 4-4 [W18A4].>
3) Using cable clip, secure ABSCM&H/U harness to
bracket.
4) Connect connector to ABSCM&H/U.
CAUTION:

Be sure to remove all foreign matter from inside the
connector before connecting.

Ensure that the ABSCM&H/U connector is securely
locked.
5) Install air intake duct.
6) Connect ground cable to battery.
7) Bleed air from the brake system.
23. ABS Sensor (ABS 5.3i Type)
<Ref. to 4-4 [W1400].>
24. G Sensor (ABS 5.3i Type)
<Ref. to 4-4 [W1700].>
130
4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type) - 24. G Sensor (ABS 5.3i Type)

B4M1222
E: INSTALLATION
1) Install ABSCM&H/U.
CAUTION:
Confirm that the specifications of the ABSCM&H/U
conforms to the vehicle specifications.
Tightening torque:
18±5 N⋅m (1.8±0.5 kg-m, 13.0±3.6 ft-lb)
2) Connect brake pipes to their correct ABSCM&H/U con-
nections. <Ref. to 4-4 [W18A4].>
3) Using cable clip, secure ABSCM&H/U harness to
bracket.
4) Connect connector to ABSCM&H/U.
CAUTION:

Be sure to remove all foreign matter from inside the
connector before connecting.

Ensure that the ABSCM&H/U connector is securely
locked.
5) Install air intake duct.
6) Connect ground cable to battery.
7) Bleed air from the brake system.
23. ABS Sensor (ABS 5.3i Type)
<Ref. to 4-4 [W1400].>
24. G Sensor (ABS 5.3i Type)
<Ref. to 4-4 [W1700].>
130
4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type) - 24. G Sensor (ABS 5.3i Type)

B4M1222
E: INSTALLATION
1) Install ABSCM&H/U.
CAUTION:
Confirm that the specifications of the ABSCM&H/U
conforms to the vehicle specifications.
Tightening torque:
18±5 N⋅m (1.8±0.5 kg-m, 13.0±3.6 ft-lb)
2) Connect brake pipes to their correct ABSCM&H/U con-
nections. <Ref. to 4-4 [W18A4].>
3) Using cable clip, secure ABSCM&H/U harness to
bracket.
4) Connect connector to ABSCM&H/U.
CAUTION:

Be sure to remove all foreign matter from inside the
connector before connecting.

Ensure that the ABSCM&H/U connector is securely
locked.
5) Install air intake duct.
6) Connect ground cable to battery.
7) Bleed air from the brake system.
23. ABS Sensor (ABS 5.3i Type)
<Ref. to 4-4 [W1400].>
24. G Sensor (ABS 5.3i Type)
<Ref. to 4-4 [W1700].>
130
4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type) - 24. G Sensor (ABS 5.3i Type)

1. Entire Brake System
Trouble and possible cause Corrective action
1. Insufficient braking
(1) Fluid leakage from the hydraulic mechanismRepair or replace (cup, piston seal, piston boot, master cylinder
piston kit, pipe or hose).
(2) Entry of air into the hydraulic mechanism Bleed the air.
(3) Excessively wide shoe clearance Adjust the clearance.
(4) Wear, deteriorated surface material, adhering water or fluid
on the liningReplace, grind or clean.
(5) Improper operation of master cylinder, disc caliper, brake
booster or check valveCorrect or replace.
2. Unstable or uneven braking
(1) Fluid on the lining, drum or rotor Eliminate cause of fluid leakage, clean, or replace.
(2) Drum or rotor eccentricity Correct or replace the drum or rotor.
(3) Worn brake drum, or damage to the drum caused by sand Correct by grinding, or replace.
(4) Improper lining contact, deteriorated surface material,
improper inferior material, or wearCorrect by grinding, or replace.
(5) Deformed back plate Correct or replace.
(6) Improper tire inflation Inflate to correct pressure.
(7) Disordered wheel alignment Adjust alignment.
(8) Loosened back plate or the support installing bolts Retighten.
(9) Loosened wheel bearing Retighten to normal tightening torque or replace.
(10) Trouble in the hydraulic system Replace the cylinder, brake pipe or hose.
(11) Uneven effect of the parking brake Check, adjust, or replace the rear brake and cable system.
3. Excessive pedal stroke
(1) Entry of air into the hydraulic mechanism Bleed the air.
(2) Excessive play in the master cylinder push rod Adjust.
(3) Fluid leakage from the hydraulic mechanismRepair or replace (cup, piston seal, piston boot, master cylinder
piston kit, pipe or hose).
(4) Improperly adjusted shoe clearance Adjust.
(5) Improper lining contact or worn lining Correct or replace.
131
4-4DIAGNOSTICS
1. Entire Brake System

Trouble and possible cause Corrective action
4. Brake dragging or improper brake return
(1) Insufficient pedal play Adjust play.
(2) Improper master cylinder return Clean or replace the cylinder.
(3) Clogged hydraulic system Replace.
(4) Improper return or adjustment of parking brake Correct or adjust.
(5) Weakened spring tension or breakage of shoe return spring Replace the spring.
(6) Excessively narrow shoe clearance Adjust the clearance.
(7) Improper disc caliper operation Correct or replace.
(8) Improper adjusted wheel bearing Adjust or replace.
5. Brake noise (1) (creak sound)
(1) Hardened or deteriorated lining Replace the shoe assembly or pad.
(2) Worn lining Replace the shoe assembly or pad.
(3) Loosened back plate or the support installing bolts Retighten.
(4) Loose wheel bearing Retighten to normal tightening torque.
(5) Dirty drum or rotor Clean the drum or rotor, or clean and replace the brake assembly.
6. Brake noise (2) (hissing sound)
(1) Worn lining Replace the shoe assembly or pad.
(2) Improper installed shoe or pad Correct or replace the shoe assembly or pad.
(3) Loose or bent drum or rotor Retighten or replace.
7. Brake noise (3) (click sound)
In the case of the disc brake:
(1) Excessively worn pad or the support Replace the pad or the support.
In the case of the drum brake:
(1) Excessively worn shoe ridge Replace the back plate.
(2) Lack of oil on the shoe ridge surface and anchor Add more grease.
132
4-4DIAGNOSTICS
1. Entire Brake System

2. Hill Holder
Trouble and possible cause Corrective action
1. Counterforce of clutch pedal is too strong.
(1) PHV cable is damaged or does not operate properly. Repair or replace.
(2) Lever of PHV is defective. Replace entire PHV assembly.
(3) Clutch system is anomalous. Refer to“Clutch and pedal cable system”.
2. Vehicle does not stop on uphill road of 3°or higher inclination.
(1) Front side of vehicle is lowered. Refer to“Suspension”.
(2) PHV cable is broken. Replace.
(3) Play of clutch is excessive. Adjust.
(4) PHV cable is elongated. Adjust.
(5) Sealing of PHV is poor. Replace entire PHV assembly.
3. Shock is felt when starting.
(1) Poor adjustment of starting performance: Adjust.
(2) When depressing the brake pedal strongly:(The stronger brake pedal depressing force, the later hill holder
releases.)
(3) When starting on flat road after stopping reverse movement: (Because hill holder is activated.)
4. Vehicle slips down when starting.
(1) PHV cable is elongated. Adjust.
(2) Clutch facing is worn out. Adjust or replace.
(3) Bracket (cable) or stay (PHV) is deformed. Repair or replace.
5. Vehicle cannot start after stoppage.
(1) Return spring is fatigued or broken. Replace.
(2) PHV lever won’t return. Replace entire PHV assembly.
(3) When intentionally depressing brake pedal strongly:[When the brake pedal is depressed by a force of 1,177 N (120
kg, 265 lb) or more.]
6. Abnormal sound is generated upon releasing brake pedal when stopping.
(1) Rotor and pad matched with each other due to inadequate
depressing force to brake pedal.(Abnormal sound is not generated when depressing brake pedal a
little stronger.)
7. Abnormal sound is generated when operating clutch pedal.
(1) Grease is inadequate for the hook of return spring and slid-
ing portion of PHV cable end.Apply grease.
(2) When releasing after maintaining high fluid pressure: (Flowing sound of fluid when releasing high fluid pressure.)
(3) Clutch system is anomalous. Refer to“Clutch and pedal cable system”.
CAUTION:

Description in parentheses is a characteristic of hill holder and does not indicate abnormality.
Depressing force required for clutch pedal equipped to hill holder specifications is 20 to 29 N (2 to 3 kg, 4 to 7 lb) larger than
the conventional specifications, which does not constitute abnormality.

When vehicle cannot travel (brake cannot be released) because return spring is broken, remove adjusting nut, disconnect
clutch and PHV, and then return PHV lever to release the brake. (Be sure to apply the parking brake before starting this opera-
tion.)

The hill holder may not be activated on a slope of an extremely small inclination.
133
4-4DIAGNOSTICS
2. Hill Holder