Page 2577 of 2870

AUTOMATIC TRANSMISSION
(DIAGNOSTIC)
4AT(H4DOTC)
Page
1. Basic Diagnostic Procedure ........................................................................2
2. Check List for Interview ...............................................................................4
3. General Description ....................................................................................5
4. Electrical Components Location..................................................................8
5. Transmission Control Module (TCM) I/O Signal .......................................12
6. Subaru Select Monitor...............................................................................15
7. Read Diagnostic Trouble Code (DTC) ......................................................18
8. Inspection Mode ........................................................................................19
9. Clear Memory Mode..................................................................................20
10. Power Indicator Light Display....................................................................21
11. Diagnostic Procedure for Subaru Select Monitor Communication ............27
12. List of Diagnostic Trouble Code (DTC) .....................................................30
13. Diagnostic Procedure with Diagnostic Trouble Code (DTC) .....................33
14. Diagnostic Procedure without Diagnostic Trouble Code (DTC) ..............112
15. Symptom Related Diagnostic ..................................................................126
Page 2578 of 2870

4AT(H4DOTC)-2
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Basic Diagnostic Procedure
1. Basic Diagnostic Procedure
A: PROCEDURE
Step Check Yes No
1 CHECK PRE-INSPECTION.
1) Ask the customer when and how trouble
occurred using interview checklist.
4AT(H4DOTC)-4, Check List for Interview.>
2) Before performing the diagnosis, inspect
following items which might influence the AT
problems.
General inspection
5, INSPECTION, General Description.>
Disconnection of harness connector
Visually check the damage of harness
Oil leak
Stall speed test
Line pressure test
Pressure Test.>
Transfer clutch pressure test
38, Transfer Clutch Pressure Test.>
Time lag test
Te s t . >
Road test
Inhibitor switch
Switch.>Is the unit that might influence
AT problem normal?Go to step 2.Repair or replace
each item.
2 CHECK POWER INDICATOR LIGHT.
Turn the ignition switch to ON.Does the POWER indicator
light illuminate?Go to step 4.Go to step 3.
3 CHECK POWER INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Repair the POWER indicator light circuit or
power supply and ground line circuit.
Power Indicator Light Display.>
3) Turn the ignition switch to ON.Is the POWER indicator light
flashing?Go to step 4.Go to step 5.
4 READ OF DTC.
Calling up the DTC.
N
OTE:
If the communication function of Subaru Select
Monitor cannot be executed normally, check the
communication circuit.
27, COMMUNICATION FOR INITIALIZING IM-
POSSIBLE, Diagnostic Procedure for Subaru
Select Monitor Communication.>Is the DTC displayed? Go to step 6.
NOTE:
Record all DTC.Go to step 5.
5 PERFORM THE GENERAL DIAGNOSTICS.
1) Inspect using “Diagnostics Procedure with-
out DTC”.
nostic Procedure without Diagnostic Trouble
Code (DTC).>
2) Inspect using “Symptom Related Diagnos-
tic”.
Related Diagnostic.>
3) Perform the clear memory mode.
4) Perform the inspection mode.
4AT(H4DOTC)-19, Inspection Mode.>
5) Calling up the DTC.Is the DTC displayed? Go to step 6.Complete the
diagnosis.
Page 2579 of 2870
4AT(H4DOTC)-3
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Basic Diagnostic Procedure
6 PERFORM THE DIAGNOSIS.
1) Inspect using “Diagnostics Procedure with
DTC”.
Procedure with Diagnostic Trouble Code
(DTC).>
N
OTE:
For DTC table, refer to “List of DTC”.
4AT(H4DOTC)-30, List of Diagnostic Trouble
Code (DTC).>
2) Repair the trouble cause.
3) Perform the clear memory mode.
4) Perform the inspection mode.
4AT(H4DOTC)-19, Inspection Mode.>
5) Calling up the DTC.Is DTC displayed? Inspect using
“Diagnostics pro-
cedure with Diag-
nostic Trouble code
(DTC)”.
4AT(H4DOTC)-33,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>Complete the
diagnosis. Step Check Yes No
Page 2580 of 2870

4AT(H4DOTC)-4
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Check List for Interview
2. Check List for Interview
A: CHECK
Check the following items when problem has occurred.
NOTE:
Use copies of this page for interviewing customers.
Customer’s name
Date of purchase
Date of repair
Trans. model TRANSMISSION VIN
Odometer readingkm/h or miles
Frequency❏ Continuous ❏ Intermittent ( times a day)
Weather❏ Fine ❏ Cloudy ❏ Rainy ❏ Snowy
❏ Va r i o u s / O t h e r s
()
Place❏ High ❏ Suburbs ❏ Inner city ❏ Uphill ❏ Rough road
❏ Others
()
Outdoor temperature❏ Hot ❏ War m ❏ Cool ❏ Cold
Vehicle speedkm/h (MPH)
AT warning light (POWER indicator
light)❏ Continuously blinking❏ Not blinking
Select lever position❏ P ❏ R ❏ N ❏ D ❏ 3 ❏ 2 ❏ 1
Driving condition❏ Not affected
❏ At racing
❏ While decelerating❏ At starting
❏ While accelerating
❏ While turning (❏ RH / ❏ LH)❏ While idling
❏ While cruising
POWER switch❏ ON / ❏ OFF
HOLD switch❏ ON / ❏ OFF
Symptoms❏ No up-shift
❏ No down-shift
❏ No kick down
❏ Vehicle does not move (❏ Any position ❏ Particular position)
❏ Lock-up malfunction
❏ Noise or vibration
❏ Shift shock or slip
❏ Select lever does not move
❏ Others
()
Page 2581 of 2870

4AT(H4DOTC)-5
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
3. General Description
A: CAUTION
Supplemental Restraint System “Airbag”
The airbag system wiring harness is routed near
the TCM.
CAUTION:
All airbag system wiring harness and con-
nectors are colored yellow. Do not use an elec-
trical test equipment on these circuit.
Be careful not to damage the airbag system
wiring harness when performing diagnostics and
servicing the TCM.
Measurement
When measuring the voltage and resistance of
ECM, TCM or each sensor, use a tapered pin with
diameter of less than 0.64 mm (0.025 in) in order to
avoid poor contact. Do not insert the pin more than
0.65 mm (0.026 in).
B: INSPECTION
1. BATTERY
Measure the battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V or more
Specific gravity: Above 1.260
2. TRANSMISSION GROUND
Make sure that the ground terminal bolt is tightened
securely.
Chassis side
Tightening torque:
13 N
⋅m (1.3 kgf-m, 9.4 ft-lb)
3. ATF LEVEL
Make sure that ATF level is in the specification.
to 4AT-30, INSPECTION, Automatic Transmission
Fluid.>
4. FRONT DIFFERENTIAL OIL LEVEL
Make sure that front differential oil level is in the spec-
ification.
Gear Oil.>
AT-00412
(A) Level gauge
(B) “HOT” side
(C) Upper level
(D) Lower level
(E) “COLD” side
(A) Upper level
(B) Lower level
PI-00105
COLD
LFHOT LF
(A)
(C)
(D)
(C)
(D)
(E)
(B)
AT-00317
(A)
(B)
LF
Page 2582 of 2870
4AT(H4DOTC)-6
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
5. OPERATION OF SELECT LEVER
Make sure there is no abnormal noise, dragging or
contact pattern in each select lever range.
WARNING:
Stop the engine while checking operation of se-
lect lever.
6. POWER SWITCH
Make sure that the POWER indicator light in com-
bination meter comes on, when turning the POW-
ER switch to ON.
7. HOLD SWITCH
Make sure that the HOLD indicator light in combina-
tion meter comes on, when turning the HOLD switch
to ON.
AT-00413
P
R
N
D
3
2
1
AT-00319
AT-00320
Page 2583 of 2870
4AT(H4DOTC)-7
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
C: PREPARATION TOOL
1. SPECIAL TOOL
2. GENERAL TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
24082AA230
(Newly adopted tool)CARTRIDGE Troubleshooting for electrical system.
22771AA030 SUBARU SELECT
MONITOR KITTroubleshooting for electrical system.
English: 22771AA030 (Without printer)
German: 22771AA070 (Without printer)
French: 22771AA080 (Without printer)
Spanish: 22771AA090 (Without printer)
TOOL NAME REMARKS
Circuit tester Used for measuring resistance, voltage and current.
Oscilloscope Used for measuring sensor.
ST24082AA230
ST22771AA030
Page 2584 of 2870
4AT(H4DOTC)-8
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Electrical Components Location
4. Electrical Components Location
A: LOCATION
1. CONTROL MODULE
LHD MODEL
RHD MODEL
(1) Engine control module (ECM) (3) Transmission control module
(TCM)(4) Data link connector
(2) AT diagnostic warning light
(POWER indicator light)
AT-00414
(1) (2)
(3) (4)
AT-00369 (2)
(4)
(1)
(3)