Subaru Legacy III (2000-2003 year). Manual - part 517

EN(H4DOSTC)-238

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

BM:DTC P1698 — ENGINE TORQUE CONTROL CUT SIGNAL CIRCUIT MAL-

FUNCTION (LOW INPUT) —

• DTC DETECTING CONDITION:

• Two consecutive driving cycles with fault

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode<Ref. to EN(H4DOSTC)-35, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOSTC)-33, OPERATION, In-
spection Mode.> .
• WIRING DIAGRAM:

EN-01007

B136 ECM

14

10

TCM

B55

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

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

EN(H4DOSTC)-239

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK OUTPUT SIGNAL FROM ECM.
1) Start engine, and warm-up the engine.
2) Turn ignition switch to OFF.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and chas-

sis ground.

Connector & terminal

(B136) No. 14 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

3 V

Repair poor con-
tact in ECM con-
nector.

Go to step 2.

2

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

TCM.

3) Measure resistance of harness between 

ECM and chassis ground.

Connector & terminal

(B136) No. 14 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 3.

Repair ground 
short circuit in har-
ness between 
ECM and TCM 
connector.

3

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

Connector & terminal

(B136) No. 14 — (B55) No. 10:

Is the measured value less than the specified 
value?

1 

Ω

Repair poor con-
tact in ECM or 
TCM connector.

Repair open circuit 
in harness 
between ECM and 
TCM connector.

EN(H4DOSTC)-240

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

BN:DTC P1699 — ENGINE TORQUE CONTROL CUT SIGNAL CIRCUIT MAL-

FUNCTION (HIGH INPUT) —

• DTC DETECTING CONDITION:

• Two consecutive driving cycles with fault

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode<Ref. to EN(H4DOSTC)-35, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOSTC)-33, OPERATION, In-
spection Mode.> .
• WIRING DIAGRAM:

EN-01007

B136 ECM

14

10

TCM

B55

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

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

EN(H4DOSTC)-241

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK OUTPUT SIGNAL FROM ECM.
1) Start engine, and warm-up the engine.
2) Turn ignition switch to OFF.
3) Disconnect connector from TCM.
4) Turn ignition switch to ON.
5) Measure voltage between ECM and chas-

sis ground.

Connector & terminal

(B136) No. 14 (+) — Chassis ground (

−−−−

):

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

3 V

Go to step 2.

Repair battery 
short circuit in har-
ness between 
ECM and TCM 
connector. After 
repair, replace 
ECM. <Ref. to 
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

2

CHECK HARNESS BETWEEN ECM AND 
TCM CONNECTOR.
1) Turn ignition switch to OFF.
2) Measure voltage between ECM and chas-

sis ground.

Connector & terminal

(B136) No. 14 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value by shaking harness and connec-
tor of ECM while monitoring the value with 
voltage meter?

10 V

Repair battery 
short circuit in har-
ness between 
ECM and TCM 
connector. After 
repair, replace 
ECM. <Ref. to 
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

Contact SUBARU 
distributor service.

NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.