Subaru Legacy IV (2008 year). Service manual — part 903

ABS(diag)-11

Control Module I/O Signal

ABS (DIAGNOSTICS)

*1: Measure the I/O signal voltage after disconnecting the connector from the ABSCM&H/U terminal.

Description

Terminal

No.

(+) — (–)

Input/Output signal

Measured value and measuring conditions

ABS wheel speed sensor
(Wheel speed sensor)

Front LH wheel

Power supply

16 — 15

4.5 — 16.5 V

Signal

1

5.9 — 16.8 mA: Rectangle waveform

Front RH wheel

Power supply

5 — 15

4.5 — 16.5 V

Signal

6

5.9 — 16.8 mA: Rectangle waveform

Rear LH wheel

Power supply

2 — 15

4.5 — 16.5 V

Signal

17

5.9 — 16.8 mA: Rectangle waveform

Rear RH wheel

Power supply

3 — 15

4.5 — 16.5 V

Signal

4

5.9 — 16.8 mA: Rectangle waveform

CAN communication line (+)

26

2.5 — 1.5 V pulse signal

CAN communication line (–)

11

3.5 — 2.5 V pulse signal

Valve relay power supply *1

14 — 15

10 — 15 V

Motor relay power supply *1

13 — 15

10 — 15 V

G sensor

Power supply

24 — 10

4.75 — 5.25 V

Ground

10

—

Output

21 — 10

2.1 — 2.5 V when the vehicle is on level surface

Stop light switch *1

20 — 15

1.5 V or less when the stop light is OFF; otherwise,

10 — 15 V when the stop light is ON.

ABS warning light

22 — 15

After turning the ignition switch to ON, 10 — 15 V during
1.5 seconds and 1.5 V or less after 1.5 seconds passed.

Brake warning light (EBD warning light)

8 — 15

After turning the ignition switch to ON, 10 — 15 V during
1.5 seconds and 1.5 V or less after 1.5 seconds passed.

Subaru Select Monitor

7 — 15

1.5 V or less when no data is received. 0

mo 12 V pulse

(in communication)

Power supply *1

18 — 15

10 — 15 V when the ignition switch is ON.

Grounding line

15

—

Vehicle speed output signal

23 — 15

0

mo 5 V pulse

ABS(diag)-12

Control Module I/O Signal

ABS (DIAGNOSTICS)

B: WIRING DIAGRAM

(1)

Battery

(11)

Front outlet solenoid valve RH

(21)

Brake warning light

(2)

Ignition switch

(12)

Rear inlet solenoid valve LH

(22)

Parking brake switch

(3)

ABS control module and hydraulic
control unit (ABSCM&H/U)

(13)

Rear outlet solenoid valve LH

(23)

Brake fluid level switch

(14)

Rear inlet solenoid valve RH

(24)

Stop light switch

(4)

ABS control module

(15)

Rear outlet solenoid valve RH

(25)

Stop light

(5)

Valve relay

(16)

Body integrated unit

(26)

G sensor

(6)

Motor relay

(17)

Engine control module (ECM)

(27)

Front ABS wheel speed sensor LH

(7)

Motor

(18)

Transmission control module (TCM)

(28)

Front ABS wheel speed sensor RH

(8)

Front inlet solenoid valve LH

(19)

Data link connector

(29)

Rear ABS wheel speed sensor LH

(9)

Front outlet solenoid valve LH

(20)

ABS warning light

(30)

Rear ABS wheel speed sensor RH

(10)

Front inlet solenoid valve RH

(3)

(7)

(8)

M

(9)

(10)

(19)

(20)

(2)

(4)

(5)

(6)

(1)

(21)

(22)

(24)

(25)

(26)

(27)

(11)

(12)

(13)

(14)

(15)

(28)

(29)

(30)

(23)

(16)

(17)

(18)

ABS01083

ABS(diag)-13

Subaru Select Monitor

ABS (DIAGNOSTICS)

6. Subaru Select Monitor

A: OPERATION

1. HOW TO USE SUBARU SELECT MONITOR

1) Prepare the Subaru Select Monitor kit. <Ref. to
ABS(diag)-7, SPECIAL TOOL, PREPARATION
TOOL, General Description.>

2) Prepare PC with Subaru Select Monitor installed.
3) Connect the USB cable between SDI (Subaru
Diagnosis Interface) and USB port on the personal
computer (dedicated port for the Subaru Select
Monitor).

NOTE:
The dedicated port for the Subaru Select Monitor
means the USB port which was used to install the
Subaru Select Monitor.
4) Connect the diagnosis cable to SDI.

5) Connect SDI to data link connector located in the low-
er portion of the instrument panel (on the driver’s side).

CAUTION:
Do not connect scan tools other than the Suba-
ru Select Monitor.
6) Start the PC.
7) Turn the ignition switch to ON (engine OFF) and
run the “PC application for Subaru Select Monitor”.

NOTE:
For detailed operation procedures, refer to the “PC
application help for Subaru Select Monitor”.
8) If communication is not possible between the
ABS and the Subaru Select Monitor, check the
communication circuit. <Ref. to ABS(diag)-15,
COMMUNICATION FOR INITIALIZING IMPOSSI-
BLE, INSPECTION, Subaru Select Monitor.>

2. READ CURRENT DATA

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 displayed.
4) On the «Brake Control Diagnosis» display, select the {Current Data Display & Save}.
5) On the «Data Display Menu» display, select the data display method.
6) Using the scroll key, scroll the display screen up or down until necessary data is shown.
• A list of the support data is shown in the following table.

NOTE:
For detailed operation procedures, refer to the “PC application help for Subaru Select Monitor”.

EN-05692

(1) Data link connector

ABS00465

(1)

Display

Contents to be displayed

Unit of measure

FR Wheel Speed

Wheel speed detected by front ABS wheel speed sensor RH is displayed.

km/h or MPH

FL Wheel Speed

Wheel speed detected by front ABS wheel speed sensor LH is displayed.

km/h or MPH

RR Wheel Speed

Wheel speed detected by rear ABS wheel speed sensor RH is displayed.

km/h or MPH

RL Wheel Speed

Wheel speed detected by rear ABS wheel speed sensor LH is displayed.

km/h or MPH

BLS Signal

Brake ON/OFF is displayed.

ON or OFF

G-Sensor

Vehicle acceleration detected by analog G sensor is displayed.

m/s (m/s

2

)

Valve Relay Signal

Valve relay operation signal is displayed.

ON or OFF

ABS Warning Light

ON operation of the ABS warning light is displayed.

ON or OFF

EBD Warning Light

ON operation of the EBD warning light is displayed.

ON or OFF

M. Relay monitor Voltage

Motor relay monitor voltage is displayed.

V

ABS_CM Power Voltage

Voltage supplied to ABSCM&H/U is displayed.

V

ABS Control Flag

ABS control condition is displayed.

ON or OFF

ABS OK B Signal

ABS system normal/abnormal is displayed.

OK or NG

ABS(diag)-14

Subaru Select Monitor

ABS (DIAGNOSTICS)

3. ABS SEQUENCE CONTROL

4. FREEZE FRAME DATA

NOTE:
• Data stored at the time of trouble occurrence is
shown on display.
• Each time a trouble occurs, the latest information
is stored in the freeze frame data in memory.
• Up to 3 freeze frame data will be stored.
• If freeze frame data is not stored in memory
properly (due to a drop in ABS control module pow-
er supply etc.), a DTC suffixed with a question mark
“?” is displayed on Subaru Select Monitor display
screen. This shows it may be an unreliable reading.

Display

Contents to be displayed

Index No.

ABS
Sequence
Control
Mode

Operate the valve and
pump motor continuously
to perform the ABS
sequence control.

<Ref. to ABS-
10, ABS
Sequence Con-
trol.>

Display

Contents to be displayed

FR Wheel
Speed

Wheel speed detected by front ABS
wheel speed sensor RH is displayed in
km/h or MPH.

FL Wheel Speed

Wheel speed detected by front ABS
wheel speed sensor LH is displayed in
km/h or MPH.

RR Wheel
Speed

Wheel speed detected by rear ABS
wheel speed sensor RH is displayed in
km/h or MPH.

RL Wheel
Speed

Wheel speed detected by rear ABS
wheel speed sensor LH is displayed in
km/h or MPH.

ABS_CM Power
Voltage

Voltage (V) supplied to ABSCM&H/U is
displayed.

G-Sensor

Vehicle acceleration detected by analog
G sensor is displayed.

M. Relay monitor
Voltage

Motor relay condition is displayed.

BLS Signal

Brake ON/OFF is displayed.

Vehicle Speed

Vehicle speed calculated by ABS control
module is displayed.

ABS Control
Flag

ABS control condition is displayed.

Power Supply
Failure

Whether abnormal voltage occurred or
not is displayed during malfunction.