Subaru Legacy (2005 year). Manual - part 755

ABS-5

ABS

General Description

D: PREPARATION TOOL

1. SPECIAL TOOL

2. GENERAL TOOL

ILLUSTRATION

TOOL NUMBER

DESCRIPTION

REMARKS

18482AA000

(Newly adopted tool)

CARTRIDGE

Troubleshooting for electrical system.

22771AA030

SUBARU SELECT 
MONITOR KIT

Troubleshooting for electrical system.
• English: 22771AA030 (Without printer)
• German: 22771AA070 (Without printer)
• French: 22771AA080 (Without printer)
• Spanish: 22771AA090 (Without printer)

TOOL NAME

REMARKS

Circuit tester

Used for measuring resistance, voltage and ampere.

Pressure gauge

Used for measuring oil pressure.

Oscilloscope

Used for measuring sensor.

TORX

®

 BIT E5

Used for replacing ABS control module.

ST18482AA000

ST22771AA030

ABS-6

ABS

ABS Control Module and Hydraulic Control Unit (ABSCM&H/U)

2. ABS Control Module and Hy-

draulic Control Unit (AB-
SCM&H/U)

A: REMOVAL

1) Disconnect the ground cable from battery.
2) Use compressed air to get rid of water around
the ABSCM&H/U.

NOTE:
When dust and dirt are attached to the terminal,
they may cause poor contact.
3) Disconnect the ABSCM&H/U connector pulling
up the lock lever.

CAUTION:
Do not pull the harness when disconnecting 
connector.

4) Remove the harness clip.
5) Disconnect the brake pipes from ABSCM&H/U.
6) Wrap the brake pipe using a vinyl bag not to spill
the brake fluid on the vehicle body.

CAUTION:
When brake fluid is attached to the vehicle 
body, wash it off with water and wipe the water.
7) Loosen the nuts and remove the ABSCM&H/U.

CAUTION:
• Do not drop or bump the ABSCM&H/U.
• Do not turn ABSCM&H/U upside down or
place it sideways for storage.
• Be careful that no foreign objects are mixed
in ABSCM&H/U.
• Be careful that no water enters inside the
connectors.

8) Remove the ABSCM&H/U bracket.

B: INSTALLATION

1) Install the ABSCM&H/U bracket.

Tightening torque:

33 N

⋅

m (3.4 kgf-m, 24.3 ft-lb)

2) Install the ABSCM&H/U aligning the groove of
damper on ABSCM&H/U side with the pawl of
bracket.

NOTE:
Check the identification mark of ABSCM&H/U.

Tightening torque:

7.5 N

⋅

m (0.76 kgf-m, 5.5 ft-lb)

3) Connect the brake pipes to their correct AB-
SCM&H/U positions.

Tightening torque:

15 N

⋅

m (1.5 kgf-m, 10.8 ft-lb)

4) Using a harness clip, secure the ABSCM&H/U
harness to bracket.
5) Connect the connector to ABSCM&H/U.

NOTE:
• Be sure to remove all foreign matters from inside
the connector before connecting.
• Ensure the ABSCM&H/U connector is securely
locked.
6) Bleed air from the brake system.

ABS00382

ABS00383

ABS00383

ABS-7

ABS

ABS Control Module and Hydraulic Control Unit (ABSCM&H/U)

C: INSPECTION

1) Check the connected and fixed condition of con-
nector.
2) Check the mark used for ABSCM&H/U identifi-
cation.
Refer to “SPECIFICATION” for mark. <Ref. to
ABS-2, SPECIFICATION, General Description.>

1. CHECKING THE HYDRAULIC UNIT ABS 
OPERATION BY PRESSURE GAUGE

1) Lift-up the vehicle, and then remove the wheels.
2) Disconnect the air bleeder screws from the FL
and FR caliper bodies.
3) Connect two pressure gauges to the FL and FR
caliper bodies.

CAUTION:
• Pressure gauges used exclusively for brake
fluid must be used.
• Do not use the pressure gauge for the mea-
surement of transmission oil pressure since
the piston seal may be expanded and de-
formed.

NOTE:
Wrap a sealing tape around the pressure gauge.

4) Bleed air from the pressure gauges and the FL
and FR caliper bodies.
5) Perform ABS sequence control.
<Ref. to ABS-10, ABS Sequence Control.>

6) When the hydraulic unit begins to work, first the
FL side performs decompression, holding and
compression, and then the FR side performs de-
compression, holding and compression.
7) Read values indicated on the pressure gauge
and check if the fluctuation of the values between
decompression and compression meets the speci-
fication. Depress the brake pedal and check that
the kick-back is normal, and tightness is normal.

8) Remove the pressure gauges from the FL and
FR caliper bodies.
9) Connect the air bleeder screws of the FL and FR
caliper bodies.
10) Remove the air bleeder screws from the RL
and RR caliper bodies.
11) Connect two pressure gauges to the RL and
RR caliper bodies.
12) Bleed air from the brake system.
13) Bleed air from the pressure gauges and the RL
and RR caliper bodies.
14) Perform ABS sequence control.
<Ref. to ABS-10, ABS Sequence Control.>
15) When the hydraulic unit begins to work, first the
RR side performs decompression, holding and
compression, and then the RL side performs de-
compression, holding and compression.
16) Read values indicated on the pressure gauge
and check if the fluctuation of the values between
decompression and compression meets the speci-
fication. Depress the brake pedal and check that
the kick-back is normal, and tightness is normal.
17) Remove the pressure gauge from the RL and
RR caliper bodies.
18) Connect the air bleeder screws of the RL and
RR caliper bodies.
19) Bleed air from the brake system.

(1) Mark

ABS00384

(1)

ABS00134

Front wheel

Rear wheel

Initial value

3,500 kPa

(36 kgf/cm

2

, 511 psi)

3,500 kPa

(36 kgf/cm

2

, 511 psi)

When 
decom-
pressed

500 kPa

(5 kgf/cm

2

, 73 psi) 

or less

500 kPa

(5 kgf/cm

2

, 73 psi) 

or less

When com-
pressed

3,500 kPa

(36 kgf/cm

2

, 511 psi) 

or more

3,500 kPa

(36 kgf/cm

2

, 511 psi) 

or more

ABS-8

ABS

ABS Control Module and Hydraulic Control Unit (ABSCM&H/U)

2. CHECKING THE HYDRAULIC UNIT ABS 
OPERATION WITH BRAKE TESTER

1) Install the spare fuse to the FWD connector lo-
cated in the main fuse box for the model without AT
VTD.

2) Since the MT model and AT VTD model cannot
cut off the AWD circuit forcibly, set the wheels other
than measured one onto free rollers.
3) Prepare for the ABS sequence control.
<Ref. to ABS-10, ABS Sequence Control.>
4) Set the front wheels or rear wheels on the brake
tester and set the select lever to “neutral”.

5) Operate the brake tester.
6) Perform ABS sequence control.
<Ref. to ABS-10, ABS Sequence Control.>

7) When the hydraulic unit begins to work, check
the following working sequence.

(1) The FL wheel performs decompression,
holding and compression in sequence, and sub-
sequently the FR wheel repeats the cycle.
(2) The RR wheel performs decompression,
holding and compression in sequence, and sub-
sequently the RL wheel repeats the cycle.

8) Read values indicated on the brake tester and
check if the fluctuation of the values between de-
compression and compression meets the specifi-
cation.

9) After the inspection, depress the brake pedal
and check that it is not abnormally hard, and tight-
ness is normal.

D: REPLACEMENT

CAUTION:
• Because the seal of ABSCM cannot be re-
placed, do not pull or peel it with lifting up.
• Because the screw part of H/U deteriorates in
every replacement procedure, do not perform
the replacement more than five times on it.
When the malfunction is found though the re-
placement that performed is less than five
times, replace the H/U body.
• Use new screws for installation of ABSCM.
• When the sealing surface of ABSCM or H/U is
dirty or damaged and it cannot be removed or
repaired, replace it with new one.
1) Remove the ABSCM&H/U. <Ref. to ABS-6, RE-
MOVAL, ABS Control Module and Hydraulic Con-
trol Unit (ABSCM&H/U).>
2) To prevent entering foreign matter and brake flu-
id leakage, plug the oil pressure port of ABSCM&H/
U using screw plug and etc.

(1) Main fuse box

(2) FWD connector

(1) Brake tester

ABS00392

(1)

(2)

ABS00136

(1)

ABS00137

(1)

Front wheel

Rear wheel

Initial value

1,000 N

(102 kgf, 225 lbf)

1,000 N

(102 kgf, 225 lbf)

When 
decom-
pressed

500 N

(51 kgf, 112 lbf)

or less

500 N

(51 kgf, 112 lbf)

or less

When com-
pressed

1,000 N

(102 kgf, 225 lbf)

or more

1,000 N

(102 kgf, 225 lbf)

or more