engine SUBARU LEGACY 1997 Service Repair Manual

20. Hydraulic Unit for ABS/TCS System
B4M0707A
1ABS/TCS hydraulic
control unit

2Rear-RH outlet

3Front-LH outlet

4Front-RH outlet

5Rear-LH outlet

6Secondary inlet

7Primary inlet
8Secondary suction line

9Primary suction line

10Bumper

11Bracket

12Pressure switch

13Valve relay

14Motor relay
Tightening torque: N⋅m (kg-m, ft-lb)
T1: 7.4±2.0 (0.75±0.2, 5.4±1.4)
T2: 29±7 (3.0±0.7, 21.7±5.1)
T3: 32±10 (3.3±1.0, 24±7)
T4: 38±10 (3.8±1.0, 27±7)
T5: 3.1±1 (0.32±0.1, 2.3±0.7)
A: REMOVAL
1) Disconnect ground cable from battery.
2) Remove canister, air intake and air cleaner case duct
from engine compartment to facilitate removal of hydraulic
unit.
3) Disconnect brake pipes from hydraulic unit.
CAUTION:
Wrap brake pipes with vinyl bag to avoid spilling brake
fluid on vehicle body.
4) Disconnect connector from hydraulic unit.
105
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

B4M0628
5) Remove bolts which secure hydraulic unit bracket, and
remove hydraulic unit from engine compartment.
CAUTION:

Hydraulic unit cannot be disassembled. Do not
attempt to loosen bolts and nuts.

Do not drop or bump hydraulic unit.

Do not turn the hydraulic unit upside down or place
it on its side.

Be careful to prevent foreign particles from getting
into hydraulic unit.

Do not pull harness disconnecting harness connec-
tor.
B: INSPECTION
1) Check connected and fixed condition of connector.
2) Check for discontinuity or short circuits.
Condition Terminal number Standard Diagram Terminal location
Valve relayTurning off
electricity.A—B90Ω
B4M0629AB4M0630
C—F0Ω
C—E
Turning on
electricity between
A and B.
(DC 12 V)C—F
C—E0Ω
Motor relayTurning off
electricity.a—b* 57Ω
B4M0631AB4M0632
c—d
Turning on
electricity between
a and b.
(DC 12 V)c—d0Ω
*: Attach circuit tester positive probe to terminal“a”and its negative probe to terminal“b”and measure the circuit resistance.
106
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

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.
109
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.
11 5
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

2. OPERATIONAL GUIDELINES OF THE TCS
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.
B4M0639
5) Press FD2 ENT key.
B4M0624
6) When the message shown in the figure is displayed,
press ENT key.
7) Checked portions will be displayed on select monitor.
B4M0627
8) When TCS 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.
11 6
4-4SERVICE PROCEDURE
20. Hydraulic Unit for ABS/TCS System

A: REMOVAL
1) Disconnect ground cable from battery.
2) Remove air intake duct from engine compartment to
facilitate removal of ABSCM&H/U.
3) Use an air-gun to get rid of water around the
ABSCM&H/U.
CAUTION:
The contact will be insufficient if the terminal gets wet.
B4M1224A
4) Pull on the lock of the ABSCM&H/U connector to
remove it.
5) Disconnect connector from ABSCM&H/U.
CAUTION:
Be careful not to let water or other foreign matter con-
tact the ABSCM&H/U terminal.
6) Unlock cable clip.
7) Disconnect brake pipes from ABSCM&H/U.
CAUTION:
Wrap brake pipes with vinyl bag to avoid spilling brake
fluid on vehicle body.
B4M1222
8) Remove ABSCM&H/U from engine compartment.
CAUTION:

ABSCM&H/U cannot be disassembled. Do not
attempt to loosen bolts and nuts.

Do not drop or bump ABSCM&H/U.

Do not turn the ABSCM&H/U upside down or place
it on its side.

Be careful to prevent foreign particles from getting
into ABSCM&H/U.

Apply a coat of rust-preventive wax (Nippeco LT or
GB) to bracket attaching bolt after tightening.

Do not pull harness disconnecting harness connec-
tor.
122
4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

G4M0462
2. CHECKING THE HYDRAULIC UNIT ABS
OPERATION WITH BRAKE TESTER
1) In the case of AWD AT vehicles, install a spare fuse with
the FWD connector in the engine compartment to simulate
FWD vehicles.
2) Prepare for operating ABS sequence control. 4-4 [W22D1] or 4-4 [W22D2].>
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 ABS sequence control. step 1 or 4-4 [W22D2] step 1.>
6) Hydraulic unit begins to work; and check the following
working sequence.
(1) The FL wheel performs decompression, holding,
and compression in sequence, and subsequently the
FR wheel repeats the cycle.
(2) The RR wheel performs decompression, holding,
and compression in sequence, and subsequently the
RL wheel repeats the cycle.
7) Read values indicated on the brake tester and check if
the fluctuation of values, when decompressed and
compressed, meet the standard values.
Unit: N (kg, lb)
Initial value When decompressed When compressed
Front wheel 981 (100, 221) 490 (50, 110) or less 981 (100, 221) or more
Rear wheel 981 (100, 221) 490 (50, 110) or less 981 (100, 221) or more
8) After checking, also check if any irregular brake pedal
tightness is felt.
125
4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

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”.
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.
126
4-4SERVICE PROCEDURE
22. ABS Control Module and Hydraulic Control Unit (ABSCM&H/U) (ABS 5.3i Type)

G4M0319
2) If it is not in specified value, adjust it by turning adjust-
ing nut on engine side end of clutch cable.
Free play: L
3—4 mm (0.12—0.16 in)
Full stroke: A
25.5—27 mm (1.004—1.063 in)
3) Apply grease to connecting portion of clutch pedal and
clutch cable.


1Lock nut


2Adjusting nut


3Release fork
Lock nut tightening torque:
5.9±1.5 N⋅m (0.60±0.15 kg-m, 4.3±1.1 ft-lb)
G4M0320
3. ACCELERATOR PEDAL
Check pedal stroke and free play by operating accelerator
pedal by hand.
If it is not within specified value, adjust it by turning nut
connecting accelerator cable to throttle body.
Free play at pedal pad: L
1—4 mm (0.04—0.16 in)
Stroke at pedal pad: A
50—55 mm (1.97—2.17 in)


1Accelerator pedal


2Toe board


3Accelerator cable
Accelerator cable lock nut tightening torque:
14±4 N⋅m (1.4±0.4 kg-m, 10.1±2.9 ft-lb)
8
4-5SERVICE PROCEDURE
1. Pedal

B4M1191A
4. CLUTCH PEDAL (2500 cc MODEL)
1) Push release fork until operating cylinder push rod
retracts. Check that clutch fluid level in reservoir tank
increases.
2) If clutch fluid level increases, hydraulic clutch play is
correct.
3) If clutch fluid level does not increase or push rod does
not retract, clutch pedal must be adjusted. [W1F1].>
4) Check the fluid level on the outside of the clutch mas-
ter cylinder tank. If the level is below“MIN”, add clutch fluid
to bring it up to“MAX”.
Recommended clutch fluid:
FMVSS No. 116, fresh DOT 3 or DOT 4 brake fluid
B: REMOVAL
1. ACCELERATOR PEDAL (LHD MODEL)
1) Disconnect ground cable from battery.
2) Disconnect accelerator cable from throttle body.
CAUTION:
Be careful not to kink accelerator cable.
3) Remove instrument panel lower cover from instrument
panel, and connector.
G4M0322
4) Disconnect accelerator cable from accelerator pedal
lever.
G4M0335
5) Working inside engine compartment, remove casing
cap out of the toe board by turning it clockwise.
6) Pull out the cable from the toe board hole.
9
4-5SERVICE PROCEDURE
1. Pedal