Subaru Legacy IV (2008 year). Service manual — part 904

ABS(diag)-15

Subaru Select Monitor

ABS (DIAGNOSTICS)

B: INSPECTION

1. COMMUNICATION FOR INITIALIZING IMPOSSIBLE

DETECTING CONDITION:
Defective harness connector
TROUBLE SYMPTOM:
Communication is impossible between ABS and Subaru Select Monitor.
WIRING DIAGRAM:

ABS00905

B301

B40

MAIN SBF

SBF-6

No.33

B40

B301

E

E

16

7

7

15

18

ABSCM & H/U

1 2 3 4 5 6 7 8 9 10 11

16 17 18 19 20 21 22 23 24 25 26

13

12

15

14

No.13

IGNITION
SWITCH

BATTERY

DATA LINK
CONNECTOR

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

ABS(diag)-16

Subaru Select Monitor

ABS (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK IGNITION SWITCH.

Is the ignition switch ON?

Go to step 2.

Turn the ignition
switch to ON, and
select ABS mode
using Subaru
Select Monitor.

2

CHECK BATTERY.
1) Turn the ignition switch to OFF.
2) Measure the battery voltage.

Is the voltage 11 V or more?

Go to step 3.

Charge or replace
the battery.

3

CHECK BATTERY TERMINAL.

Is there poor contact at the bat-
tery terminal?

Repair or tighten
the battery termi-
nal.

Go to step 4.

4

CHECK SUBARU SELECT MONITOR COM-
MUNICATION.
1) Turn the ignition switch to ON.
2) Using the Subaru Select Monitor, check
whether communication to other systems can
be executed normally.

Is the system name displayed
on the Subaru Select Monitor?

Go to step 8.

Go to step 5.

5

CHECK SUBARU SELECT MONITOR COM-
MUNICATION.
1) Turn the ignition switch to OFF.
2) Disconnect the ABSCM&H/U connectors.
3) Turn the ignition switch to ON.
4) Check whether communication to other sys-
tems can be executed normally.

Is the system name displayed
on the Subaru Select Monitor?

Replace the
ABSCM&H/U.
<Ref. to ABS-6,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>

Go to step 6.

6

CHECK HARNESS CONNECTOR BETWEEN
EACH CONTROL MODULE AND DATA LINK
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the ABSCM&H/U, ECM and
TCM.
3) Measure the resistance between data link
connector and chassis ground.

Connector & terminal

(B40) No. 7 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 7.

Repair the harness
and connector
between each con-
trol module and
data link connec-
tor.

7

CHECK ABSCM&H/U OUTPUT SIGNAL.
1) Turn the ignition switch to ON.
2) Measure the voltage between data link con-
nector and chassis ground.

Connector & terminal

(B40) No. 7 (+) — Chassis ground (–):

Is the voltage less than 1 V?

Go to step 8.

Repair the harness
and connector
between each con-
trol module and
data link connec-
tor.

8

CHECK HARNESS CONNECTOR BETWEEN
ABSCM&H/U AND DATA LINK CONNEC-
TOR.
Measure the resistance between ABSCM&H/U
connector and data link connector.

Connector & terminal

(B301) No. 7 — (B40) No. 7:

Is the resistance less than 0.5

:? Go to step 9.

Repair harness
and connector
between
ABSCM&H/U and
data link connec-
tor.

9

CHECK INSTALLATION OF ABSCM&H/U
CONNECTOR.
Turn the ignition switch to OFF.

Is the ABSCM&H/U connector
inserted into ABSCM&H/U until
the clamp locks onto it?

Go to step 10.

Insert ABSCM&H/
U connector into
ABSCM&H/U.

10

CHECK POWER SUPPLY CIRCUIT.
1) Turn the ignition switch to ON. (engine OFF)
2) Measure the ignition power supply voltage
between ABSCM&H/U connector and chassis
ground.

Connector & terminal

(B301) No. 18 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step 11.

Repair open circuit
of harness
between
ABSCM&H/U and
battery.

ABS(diag)-17

Subaru Select Monitor

ABS (DIAGNOSTICS)

11

CHECK HARNESS CONNECTOR BETWEEN
ABSCM&H/U AND CHASSIS GROUND.
1) Turn the ignition switch to OFF.
2) Disconnect the ABSCM&H/U connectors.
3) Measure the resistance of the harness
between ABSCM&H/U connector and chassis
ground.

Connector & terminal

(B301) No. 15 — Chassis ground:

Is the resistance less than 0.5

:? Go to step 12.

Repair the open
circuit and poor
contact of the har-
ness between
ABSCM&H/U and
connector.

12

CHECK POOR CONTACT IN CONNECTOR.

Is there poor contact in control
module power supply, ground
circuit and data link connector?

Repair the connec-
tor.

Replace the
ABSCM only. <Ref.
to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>

Step

Check

Yes

No

ABS(diag)-18

Read Diagnostic Trouble Code (DTC)

ABS (DIAGNOSTICS)

7. Read Diagnostic Trouble

Code (DTC)

A: OPERATION

1) On the «Main Menu» display, select the {Each
System Check}.
2) On the «System Selection Menu» display, select
the {Brake Control System}.
3) Click the [OK] button after the {ABS} is dis-
played.
4) On the «Brake Control Diagnosis» display, se-
lect the {Diagnostic Code(s) Display}.
5) Record the DTC and data.

NOTE:
• For detailed operation procedures, refer to the
“PC application help for Subaru Select Monitor”.
• For details concerning DTCs, refer to “List of Di-
agnostic Trouble Code (DTC)”. <Ref. to ABS(diag)-
29, List of Diagnostic Trouble Code (DTC).>
• Up to 3 DTCs are displayed in the order of detec-
tion.
• If a particular DTC is not stored in memory prop-
erly at the occurrence of problem (due to a drop in
ABSCM&H/U power supply etc.), the DTC suffixed
with a question mark “?” is displayed on Subaru Se-
lect Monitor display screen. This shows it may be
an unreliable reading.
• If “No diagnostic Code Present” is displayed,
check combination meter or harness. <Ref. to
ABS(diag)-25, ABS WARNING LIGHT DOES NOT
GO OFF, ABS Warning Light / Brake Warning Light
Illumination Pattern.>
• When the ABS warning light is OFF and “No di-
agnostic Code Present” is displayed, the system is
operating properly.

Display

Contents to be displayed

(Current)

The current DTC is displayed on Subaru
Select Monitor display screen.

(Old)

The latest DTC in previous troubles is
displayed on Subaru Select Monitor dis-
play screen.

(Older)

The second latest DTC from the history
of previous problems is displayed on the
Subaru Select Monitor display screen.

(Before 3)

The third latest DTC from the history of
previous problems is displayed on Sub-
aru Select Monitor display screen.