Subaru Legacy III (2000-2003 year). Manual - part 712

ABS-66

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

W: DTC 44 A COMBINATION OF AT CONTROL ABNORMAL

DIAGNOSIS:
• Combination of AT control faults
TROUBLE SYMPTOM:
• ABS does not operate.
WIRING DIAGRAM:

ABS00310

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

16 17 18 19 20 21 22

27 28 29 30 31

23

24

25

26

F49

31

3

ABS CONTROL MODULE AND 

HYDRAULIC CONTROL UNIT

F49

TCM

B55

21

7

14

B62

F45

RHD

LHD

:LHD

F45

:RHD

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16

F45

1

2 3

4 5 6 7 8

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

ABS-67

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK SPECIFICATIONS OF THE AB-
SCM&H/U.
Check specifications of the mark to the 
ABSCM&H/U.

CG: AT (Except OUTBACK)
CH: MT (Except OUTBACK)
CI: AT (OUTBACK)
CJ: MT (OUTBACK)

Do the vehicle specification and the specifica-
tion of ABSCM&HU match?

Both are the same specifica-
tions.

Go to step 2.

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

2

CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect two connectors from TCM.
3) Disconnect connector from ABSCM&H/U.
4) Measure resistance between ABSCM&H/U 

connector and chassis ground.

Connector & terminal

(F49) No. 3 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 3.

Repair harness 
between TCM and 
ABSCM&H/U.

3

CHECK BATTERY SHORT OF HARNESS.
Measure voltage between ABSCM&H/U con-
nector and chassis ground.

Connector & terminal

(F49) No. 3 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified 
value?

1 V

Go to step 4.

Repair harness 
between TCM and 
ABSCM&H/U.

4

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM&H/U 

connector and chassis ground.

Connector & terminal

(F49) No. 3 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 5.

Repair harness 
between TCM and 
ABSCM&H/U.

5

CHECK TCM.
1) Turn ignition switch to OFF.
2) Connect all connectors to TCM.
3) Turn ignition switch to ON.
4) Measure voltage between TCM connector 

terminal and chassis ground.

Connector & terminal

(B55) No. 21 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified 
range?

10 - 15 V

Go to step 7.

Go to step 6.

6

CHECK AT.
Is the AT functioning normally?

Function of AT is normal.

Replace TCM.

Repair AT.

7

CHECK OPEN CIRCUIT OF HARNESS.
Measure voltage between ABSCM&H/U con-
nector and chassis ground.

Connector & terminal

(F49) No. 3 (+) — Chassis ground (

−−−−

):

(F49) No. 31 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified 
range?

10 - 15 V

Go to step 8.

Repair harness/
connector 
between TCM and 
ABSCM&H/U.

8

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between 
TCM and ABSCM&H/U?

There is no poor contact.

Go to step 9.

Repair connector.

ABS-68

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

9

CHECK ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Connect all connectors.
3) Erase the memory.
4) Perform inspection mode.
5) Read out the DTC.

Is the same DTC still being output?

Same DTC is not indicated.

Go to step 10.

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

10

CHECK ANY OTHER DTC APPEARANCE.
Are other DTC being output?

Other DTC is not indicated.

A temporary poor 
contact.

Proceed with the 
diagnosis corre-
sponding to the 
DTC.

Step

Value

Yes

No

ABS-69

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

MEMO: