Subaru Legacy III (2000-2003 year). Manual - part 606

AT-158

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

L: CHECK BUZZER.

DIAGNOSIS:
Buzzer output signal circuit is open or shorted.
TROUBLE SYMPTOM:
Buzzer remains sounded.
WIRING DIAGRAM:

AT-00792

BATTERY

No.

 5

IGNITION

RELA

Y

i12

i1

B36

B56

COMBINATION
METER

TCM

E

13

12

21

B36

B4 B5 B6

A4 A5 A6

C5 C6

F6

D4 D5 D6

F1

H1

C4

G6

G1

C2

K1

M1 M2

K6

L1

D1 D2

A1 A2
B1 B2

I6

J6

L2

I1

J1

H6

M4 M5 M6

L4 L5 L6 

N5 N6

O4 O5 O6

N4

P4 P5

N2

O1 O2

P1 P2

N3

O3

P3

P6

A3

B3

C3

E4 E5 E6

E1 E2

E5

BUZZER

B56

1 2

7

8

9

5 6

3 4

10 11 12
19 20 21

13

14 15

16

17

18

22

23

24

i12

1 2 3 4

5 6 7 8

9 10 11 12 13

14 15 16 17 18

AT-159

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK HARNESS BETWEEN TCM AND 
COMBINATION METER.
1) Turn ignition switch to OFF.
2) Disconnect connector from combination 

meter and TCM.

3)  Measure resistance between TCM connec-

tor and chassis ground.

Connector & terminal

(B56) No. 21 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 2.

Repair short circuit 
in harness 
between TCM and 
combination meter 
connector.

2

CHECK COMBINATION METER.
1) Connect connector to combination meter.
2) Turn ignition switch to ON. (Engine is 

stopped.)
Does buzzer sound?

Buzzer sounds.

Replace combina-
tion meter.

Go to step 3.

3

CHECK POOR CONTACT.
Is there poor contact in buzzer circuit?

There is poor contact.

Repair poor con-
tact.

Replace TCM.

AT-160

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

SYMPTOM RELATED DIAGNOSTIC

16.Symptom Related Diagnostic

A: INSPECTION

Symptom

Problem parts

Starter does not rotate when select lever is in “P” or “N”; starter 
rotates when select lever is in “R”, “D”, “3” or “2”.

• Inhibitor switch
• Select cable
• Select lever
• Starter motor and harness

Abnormal noise when select lever is in “P” or “N”.

• Strainer
• Transfer duty solenoid
• Oil pump
• Drive plate
• ATF level too high or too low

Hissing noise occurs during standing start.

• Strainer
• ATF level too high or too low

Noise occurs while driving in “D1”.

• Final gear
• Planetary gear
• Reduction gear
• Differential gear oil level too high or too low

Noise occurs while driving in “D2”.

Noise occurs while driving in “D3”.

• Final gear
• Low & reverse brake
• Reduction gear
• Differential gear oil level too high or too low

Noise occurs while driving in “D4”.

• Final gear
• Low & reverse brake
• Planetary gear
• Reduction gear
• Differential gear oil level too high or too low

Engine stalls while shifting from one range to another.

• Control valve
• Lock-up damper
• Engine performance
• Input shaft

Vehicle moves when select lever is in “N”.

• TCM
• Low clutch

Shock occurs when select lever is moved from “N” to “D”.

• TCM
• Harness
• Control valve
• ATF deterioration

Excessive time lag occurs when select lever is moved from “N” 
to “D”.

• Control valve
• Low clutch
• Line pressure duty solenoid
• Seal ring
• Front gasket transmission case

Shock occurs when select lever is moved from “N” to “R”.

• TCM
• Harness
• Control valve
• ATF deterioration

Excessive time lag occurs when select lever is moved from “N” 
to “R”.

• Control valve
• Low & reverse clutch
• Reverse clutch
• Line pressure duty solenoid
• Seal ring
• Front gasket transmission case

Vehicle does not start in any shift range (engine stalls).

• Parking brake mechanism
• Planetary gear

AT-161

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

SYMPTOM RELATED DIAGNOSTIC

Vehicle does not start in any shift range (engine revving up).

• Strainer 
• Line pressure duty solenoid
• Control valve
• Drive pinion
• Hypoid gear
• Axle shaft
• Differential gear
• Oil pump
• Input shaft
• Output shaft
• Planetary gear
• Drive plate
• ATF level too low
• Front gasket transmission case

Vehicle does not start in “R” range only (engine revving up).

• Select cable
• Select lever
• Control valve
• Low & reverse clutch
• Reverse clutch

Vehicle does not start in “R” range only (engine stalls).

• Low clutch
• 2-4 brake
• Planetary gear
• Parking brake mechanism

Vehicle does not start in “D”, “3” range only (engine revving up).

• Low clutch
• One-way clutch

Vehicle does not start in “D”, “3” or “2” range only (engine rev-
ving up).

• Low clutch

Vehicle does not start in “D”, “3” or “2” range only (engine 
stalls).

• Reverse clutch

Vehicle starts in “R” range only (engine revving up).

• Control valve

Acceleration during standing starts is poor (high stall rpm).

• Control valve
• Low clutch
• Reverse clutch
• ATF level too low
• Front gasket transmission case
• Differential gear oil level too high or too low

Acceleration during standing starts is poor (low stall rpm).

• Oil pump
• Torque converter one-way clutch
• Engine performance

Acceleration is poor when select lever is in “D”, “3” or “2” range 
(normal stall rpm).

• TCM
• Control valve
• High clutch
• 2-4 brake
• Planetary gear

Acceleration is poor when select lever is in “R” (normal stall 
rpm).

• Control valve
• High clutch
• 2-4 brake
• Planetary gear

No shift occurs from 1st to 2nd gear.

• TCM
• Rear vehicle speed sensor
• Front vehicle speed sensor
• Throttle position sensor
• Shift solenoid 1
• Control valve
• 2-4 brake

No shift occurs from 2nd to 3rd gear.

• TCM
• Control valve
• High clutch
• Shift solenoid 2

Symptom

Problem parts