Subaru Legacy IV (2008 year). Service manual — part 698

4AT(diag)-13

Transmission Control Module (TCM) I/O Signal

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

5. Transmission Control Module (TCM) I/O Signal

A: ELECTRICAL SPECIFICATION

Check with ignition switch ON.

Contents

Measured terminal

(Connector & Terminal No.)

Measuring condition

Voltage (V)

Resistance (

:)

Positive terminal

Ground terminal

Backup power supply

(B55) No. 27

Chassis ground

—

10 — 13

—

(B55) No. 26

Chassis ground

(B55) No. 25

Chassis ground

ACC power supply

(B55) No. 12

Chassis ground

Ignition

Switch ACC

10 — 13

—

Ignition power supply

(B55) No. 1

Chassis ground

Ignition

Switch ON

10 — 13

—

(B55) No. 2

Chassis ground

Inhibitor switch

“P” range
switch

(B54) No. 14

Chassis ground

Select lever

“P” range

Less than 1

—

Select lever

Except “P” range

8 or more

—

“N” range
switch

(B54) No. 11

Chassis ground

Select lever

“N” range

Less than 1

—

Select lever

Except “N” range

8 or more

—

“R” range
switch

(B54) No. 13

Chassis ground

Select lever

“R” range

Less than 1

—

Select lever

Except “R” range

8 or more

—

“D” range
switch

(B54) No. 10

Chassis ground

Select lever

“D” range

Less than 1

—

Select lever

Except “D” range

8 or more

—

ATF temperature sensor

(B54) No. 23

(B54) No. 12

ATF temperature

20°C (68°F)

3.5 — 4.3

2.5k — 7.0 k

ATF temperature

80°C (176°F)

1.0 — 2.2

300 — 800

5

6

7

8

2

1

9

4

3

10

24

22

23

25

11

12

13

14

15

26

27

28

16

17

18

19

20

21
29

30

31

32

33

34

35

B55

TO

TO

5

6

7

8

2

1

9

4

3

10

24

22

23

25

11

12

13

14

15
26

27

28

16

17

18

19

20

21

33

34

29

32

30

31

35

B54

AT-03733

4AT(diag)-14

Transmission Control Module (TCM) I/O Signal

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

ATF temperature sensor ground

(B54) No. 12

Chassis ground

—

0

Less than 1

(When inserting

connector)

f (When dis-

connecting con-

nector)

Rear vehicle speed sensor

(B54) No. 26

(B54) No. 15

20 km/h (12 MPH)

Vehicle speed at

least

2 or more

(AC range)

—

Rear vehicle speed sensor
ground

(B54) No. 15

Chassis ground

—

0

Less than 1

(When inserting

connector)

f (When dis-

connecting con-

nector)

Front vehicle speed sensor

(B54) No. 27

(B54) No. 16

—

—

450 — 650

Front vehicle speed sensor
ground

(B54) No. 16

Chassis ground

—

—

—

Torque converter turbine speed
sensor

(B54) No. 1

(B54) No. 2

Engine idling after

warm up (“D” range)

0

450 — 650

Engine idling after

warm up (“N” range)

1 or more

(AC range)

Torque converter turbine speed
sensor ground

(B54) No. 2

Chassis ground

—

—

—

Engine speed signal

(B55) No. 11

Chassis ground

Ignition switch ON

(engine OFF)

Less than 1

—

Engine start

5 or more

(AC range)

—

Line pressure linear solenoid

(B54) No. 4

(B54) No. 3

Ignition switch ON
(with engine OFF)

Throttle fully closed

in “R” range after

warm up.

3.7 — 7.7

4.0 — 6.0

Ignition switch ON
(with engine OFF)

Throttle fully closed

in “R” range after

warm up.

1.1 — 5.1

Line pressure linear solenoid
ground

(B54) No. 3

Chassis ground

—

Less than 1

Less than 1

Lock-up duty solenoid

(B54) No. 6

Chassis ground

When lock up

occurs.

10.5 or more

2.0 — 4.5

When lock up is

released.

Less than 1

Transfer duty solenoid

(B54) No. 5

Chassis ground

With fuse installed to

FWD switch

Less than 1

2.0 — 4.5

With fuse removed

from FWD switch

(1st gear)

2.0 — 3.0

2-4 brake duty solenoid

(B55) No. 4

Chassis ground

“P” or “N” range

5.0 or more

2.0 — 4.5

2nd or 4th gear

Less than 1

High clutch duty solenoid

(B55) No. 6

Chassis ground

3rd or 4th gear

Less than 1

2.0 — 4.5

“P” or “N” range

5.0 or more

Check with ignition switch ON.

Contents

Measured terminal

(Connector & Terminal No.)

Measuring condition

Voltage (V)

Resistance (

:)

Positive terminal

Ground terminal

4AT(diag)-15

Transmission Control Module (TCM) I/O Signal

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Low clutch duty solenoid

(B55) No. 7

Chassis ground

1st or 2nd gear

Less than 1

2.0 — 4.5

“P” or “N” range

5.0 or more

Low & reverse duty solenoid

(B55) No. 5

Chassis ground

Except “1” range

5.0 or more

2.0 — 4.5

Driving at 1st gear

on manual mode

(15 km/h (9.3 MPH)

or more)

2.5 — 5.0

Data link signal (Subaru Select
Monitor)

(B55) No. 8

Chassis ground

—

—

—

CAN communication signal (+)

(B54) No. 18

Chassis ground

Ignition switch ON

Pulse signal

—

CAN communication signal (–)

(B54) No. 17

Chassis ground

Ignition switch ON

Pulse signal

—

FWD switch

(B55) No. 10

Chassis ground

Fuse removed

10.5 or more

—

Fuse installed

1 or less

—

System ground circuit

(B55) No. 20

Chassis ground

—

0

Less than 1

(B55) No. 21

Chassis ground

—

0

Less than 1

(B55) No. 22

Chassis ground

—

0

Less than 1

(B55) No. 23

Chassis ground

—

0

Less than 1

Check with ignition switch ON.

Contents

Measured terminal

(Connector & Terminal No.)

Measuring condition

Voltage (V)

Resistance (

:)

Positive terminal

Ground terminal

4AT(diag)-16

Subaru Select Monitor

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

6. Subaru Select Monitor

A: OPERATION

1. READ DIAGNOSTIC TROUBLE CODE
(DTC)

1) Prepare the Subaru Select Monitor kit. <Ref. to
4AT(diag)-7, PREPARATION TOOL, General De-
scription.>
2) Prepare PC with Subaru Select Monitor in-
stalled.
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
lower portion of the instrument panel (on the driv-
er’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”.
8) On the «Main Menu» display, select the {Each
System Check}.
9) On the «System Selection Menu» display, select
the {Transmission Control System}.
10) After transmission type information pops up,
select [OK].
11) On the «Transmission Diagnosis» display, se-
lect the {Diagnostic Code(s) Display}.

12) On the «Diagnostic Code(s) Display» display,
select the {Temporary Diagnostic Code(s)} or
{Memorized Diagnostic Code(s)}.

NOTE:
• For detailed operation procedure, refer to the
“PC application help for Subaru Select Monitor”.
• For details concerning DTC, refer to “List of Diag-
nostic Trouble Code (DTC)”. <Ref. to 4AT(diag)-
30, List of Diagnostic Trouble Code (DTC).>

AT-04371