Subaru Legacy III (2000-2003 year). Manual — part 577

AT-42

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

14.Diagnostic Procedure with Diagnostic Trouble Code (DTC)

A: DTC 11 ENGINE SPEED SIGNAL

DIAGNOSIS:
Engine speed input signal circuit is open or shorted.
TROUBLE SYMPTOM:
• No lock-up (after engine warm-up).
• POWER indicator light remains on when vehicle speed is “0”.
WIRING DIAGRAM:

AT-00775

9

30

H6T

H4N

17

ECM

B55

TCM

H4N

H6T

: EXCEPT 3.0L MODEL
AND TURBO MODEL

: 3.0L MODEL
AND TURBO MODEL

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

B135

B136

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

H6

:

H4

:

B55

1 2 3 4

10 11 12
19 20 21

13

5 6

14 15

7

8

9

16

17

18

22

23

24

B136

B135 :

:

H4N

H6T

AT-43

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM and

ECM.

3) Measure resistance of harness between

TCM and ECM connector.

Connector & terminal

Except 3.0 L model and TURBO model:

(B55) No. 17 — (B135) No. 30:

3.0 L model and TURBO model:

(B55) No. 17 — (B136) No. 9:

Is the measured value less than the speci-
fied value?

1

Ω

Go to step 2.

Repair open circuit
in harness
between TCM and
ECM connector.

2

CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure resistance of harness between TCM
connector and chassis ground.

Connector & terminal

(B55) No. 17 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 3.

Repair short circuit
in harness
between TCM and
ECM connector.

3

PREPARE SUBARU SELECT MONITOR.
Do you have a Subaru Select Monitor?

Subaru Select Monitor is avail-
able.

Go to step 5.

Go to step 4.

4

CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to TCM and ECM.
2) Turn ignition switch to ON (engine OFF).
3) Measure voltage between TCM connector

and chassis ground.

Connector & terminal

(B55) No. 17 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10.5 V

Even if “POWER”
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
harness or con-
nector in the TCM
and ECM.

Go to step 6.

5

CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect connectors to TCM and ECM.
2) Connect Subaru Select Monitor to data link

connector.

3) Start the engine, and turn Subaru Select

Monitor switch to ON.

4) Warm-up the engine until engine coolant

temperature is above 80

°

C (176

°

F).

5) Engine idling.
6) Read data of engine speed using Subaru

Select Monitor.

•Display shows engine speed signal value sent
from ECM.

Is the revolution value the same as the
tachometer reading shown on the combina-
tion meter?

Tachometer and select monitor
value are the same.

Even if “POWER”
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
harness or con-
nector in the TCM
and ECM.

Go to step 6.

6

CHECK POOR CONTACT.
Is there poor contact in engine speed signal
circuit?

There is poor contact.

Repair poor con-
tact.

Go to step 7.

AT-44

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

7

CONFIRM DTC 11.
Replace ECM with a new one. Does the diag-
nostic trouble code (DTC) appear again, after
the memory has been cleared?

DTC11 is displayed.

Replace TCM.
<Ref. to AT-76,
Transmission Con-
trol Module
(TCM).>

Replace ECM.

Step

Value

Yes

No

AT-45

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO: