
4AT-74
AUTOMATIC TRANSMISSION
Transfer Duty Solenoid and Valve Body
14) Remove the select cable nut.
15) Move the gear select cable so that extension
case securing bolts can be removed.
16) Remove the bolt.
17) Remove the extension case.
NOTE:
Use a container to catch oil flowing from extension.
18) Disconnect the transfer duty solenoid connec-
tor.
19) Remove the transfer duty solenoid and transfer
valve body.B: INSTALLATION
1) Install the transfer duty solenoid and transfer
valve body.
(1) Install the transfer duty solenoid and trans-
fer valve body.
Tightening torque:
8 N
⋅m (0.8 kgf-m, 5.8 ft-lb)
(2) Connect the transfer duty solenoid connec-
tor.
2) Replace the gasket with a new one, and then in-
stall the extension case to transmission case.
(1) Tighten eleven bolts.
Tightening torque:
25 N
⋅m (2.5 kgf-m, 18.1 ft-lb)
(2) Adjust the select cable.
3) Install the rear vehicle speed sensor.
Tightening torque:
7 N
⋅m (0.7 kgf-m, 5.1 ft-lb)
(A) Transfer valve body
(B) Transfer duty solenoid connector
(C) Transfer duty solenoid
AT-00083
AT-00084
AT-00085
(A)
(C)
(B)
(A) Transfer valve body
(B) Transfer duty solenoid connector
(C) Transfer duty solenoid
AT-00086
(A)
(C)
(B)
TT
AT-00087
T

4AT-78
AUTOMATIC TRANSMISSION
Dropping Resistor
23.Dropping Resistor
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Disconnect the connector from dropping resis-
tor.
3) Remove the dropping resistor.
B: INSTALLATION
Install in the reverse order of removal.
Tightening torque:
6.4 N
⋅m (0.65 kgf-m, 4.7 ft-lb)
C: INSPECTION
(A) Dropping resistor
AT-00041
AT-00313
(A)
(A) Dropping resistor
AT-00313
(A)
Step Check Yes No
1 CHECK RESISTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from dropping
resistor.
3) Measure the resistance between dropping
resistors.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 9 — 15 Ω? Go to step 2.Replace the drop-
ping resistor.
ping Resistor.>
2 CHECK RESISTOR.
Measure the resistance between dropping
resistors.
Te r m i n a l s
No. 3 — No. 4:Is the resistance 9 — 15 Ω? Dropping resistor
is normal.Replace the drop-
ping resistor.
ping Resistor.>

4AT-84
AUTOMATIC TRANSMISSION
ATF Cooler (With Warmer Function)
25.ATF Cooler (With Warmer
Function)
A: REMOVAL
1) Drain engine coolant.
2) Remove the air cleaner case.
3) Remove the harness from bracket.
4) Disconnect the hose from pipe of transmission.
5) Disconnect the engine coolant inlet hose from
cylinder block and the engine coolant outlet hose
from upper side of engine.6) Remove the ATF Cooler (with warmer function)
from transmission body, and then disconnect the
hose located lower of ATF cooler (with warmer
function).
(A) Inlet pipe
(B) Outlet pipe
(A) Outlet hose
(B) Inlet hose
AT-01867
AT-01866(A)(B)
AT-02113
(A)
(B)
AT-01868

4AT(H4SO)-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.
2) Before performing the diagnosis, inspect
following items which might influence the AT
problems.
General inspection
Disconnection of harness connector
Visually check the damage of harness
Oil leak
Stall speed test
Line pressure test
Transfer clutch pressure test
Time lag test
Road test
Inhibitor switch
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.
3) Turn the ignition switch to ON.Is the POWER indicator light
illuminate?Go to step 4.Go to step 5.
4 CHECK INDICATION OF DTC.
Calling up the DTC.
Without Subaru Select Monitor
Diagnostic Trouble Code (DTC).>
With Subaru Select Monitor
Diagnostic Trouble Code (DTC).>
NOTE:
If the communication function of select monitor
cannot be executed normally, check the communi-
cation circuit.
Diagnostic Procedure for Subaru Select Monitor
Communication.>Is the DTC displayed? Go to step 6.
NOTE:
Record all DTC.Go to step 5.

4AT(H4SO)-28
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Power Indicator Light Display
Step Check Yes No
1 CHECK POWER INDICATOR LIGHT.
Turn the ignition switch to ON (engine OFF).Does the POWER indicator
light illuminate?Go to step 3.Go to step 2.
2 CHECK POWER INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the POWER indicator light bulb
from combination meter.Is the POWER indicator light
bulb OK?Go to step 4.Replace the
POWER indicator
light bulb.
3 CHECK POWER INDICATOR LIGHT.
Perform “Read Diagnostic Trouble Code
(DTC)”.
light blink?A temporary poor
contact of the con-
nector or harness
may be the cause.
Repair the har-
ness or connector
in TCM, inhibitor
switch and combi-
nation meter.Go to step 9.
4 CHECK FUSE (No. 14).
Remove the fuse (No. 14).Is the fuse (No. 14) blown out? Replace the fuse
(No. 14). If
replaced fuse (No.
14) is blown out
easily, repair short
circuit in harness
between fuse (No.
14) and combina-
tion meter.Go to step 5.
5 CHECK HARNESS CONNECTOR BETWEEN
COMBINATION METER AND IGNITION
SWITCH.
1) Turn the ignition switch to ON (engine
OFF).
2) Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i10) No. 9 (+) — Chassis ground (
−):Is the voltage more than 9 V? Go to step 6.Repair the open
circuit in harness
between combina-
tion meter and bat-
tery.
6 CHECK COMBINATION METER.
Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i11) No. 2 (+) — Chassis ground (
−):Is the voltage less than 9 V? Repair the combi-
nation meter.
Meter Assembly.>Go to step 7.
7 CHECK OPEN CIRCUIT OF HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from combination
meter connector.
3) Measure the resistance of harness
between combination meter.
Connector & terminal
(B56) No. 11 — (i11) No. 2:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between TCM and
combination
meter, and poor
contact in cou-
pling connector.
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connector to TCM and combi-
nation meter.
2) Turn the ignition switch to ON (engine
OFF).
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 11 (+) — Chassis ground (
−):Is the voltage less than 1 V? Even if the
POWER indicator
lights up, the cir-
cuit has returned
to a normal condi-
tion at this time. A
temporary poor
contact of the con-
nector or harness
may be the cause.
Repair the har-
ness or connector
in TCM.Replace the TCM.
trol Module
(TCM).>

4AT(H4SO)-31
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Power Indicator Light Display
Step Check Yes No
1 CHECK BATTERY TERMINAL.
Turn the ignition switch to OFF.Is there poor contact at battery
terminal?Repair or tighten
the battery termi-
nal.Go to step 2.
2 CHECK POWER SUPPLY OF TCM.
1) Disconnect the connector from TCM.
2) Turn the ignition switch to ON.
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 1 (+) — Chassis ground (
−):Is the voltage 10 — 13 V? Go to step 4.Go to step 3.
3 CHECK FUSE (NO. 4).
Remove the fuse (No. 4).Is the fuse (No. 4) blown out? Replace the fuse
(No. 4). If replaced
fuse (No. 4) has
blown out easily,
repair short circuit
in harness
between fuse (No.
4) and TCM.Repair the open
circuit in harness
between fuse (No.
4) and TCM, or
fuse (No. 4) and
battery, and poor
contact in cou-
pling connector.
4 CHECK IGNITION POWER SUPPLY CIR-
CUIT.
1) Turn the ignition switch to ON (engine
OFF).
2) Measure the ignition power supply voltage
between TCM connector and chassis ground.
Connector & terminal
(B54) No. 23 (+) — Chassis ground (–):
(B54) No. 24 (+) — Chassis ground (–):Is the voltage 10 — 13 V? Go to step 6.Go to step 5.
5 CHECK FUSE (NO. 11).
Remove the fuse (No. 11).Is the fuse (No. 11) blown out? Replace the fuse
(No. 11). If
replaced fuse (No.
11) has blown out
easily, repair short
circuit in harness
between fuse (No.
11) and TCM.Repair the open
circuit in harness
between fuse (No.
11) and TCM, or
fuse (No. 11) and
battery, and poor
contact in cou-
pling connector.
6 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
transmission.
3) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B56) No. 19 — (B11) No. 16:
(B54) No. 21 — (B11) No. 16:Is the resistance less than 1
Ω?Go to step 7.Repair the open
circuit in harness
between TCM,
transmission har-
ness connector,
and poor contact
in coupling con-
nector.
7 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND TRANSMISSION
GROUND.
Measure the resistance of harness between
transmission and transmission ground.
Connector & terminal
(T4) No. 16 — Transmission ground:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between transmis-
sion and transmis-
sion ground.
8 CHECK POOR CONTACT IN CONNECTORS.Is there poor contact in control
module power supply, ground
line and data link connector?Repair the con-
nector.Replace the TCM.
trol Module
(TCM).>

4AT(H4SO)-37
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
ECM.
3) Measure the resistance of harness
between TCM and ECM connector.
Connector & terminal
(B55) No. 17 — (B134) No. 10:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between TCM and
ECM connector.
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 17 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
ECM connector.
3 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 5.Go to step 4.
4 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and ECM.
2) Turn the ignition switch to ON (engine
OFF).
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B55) No. 17 (+) — Chassis ground (
−):Is the voltage more than 10.5
V?Even if the
POWER indicator
light was blinking,
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
the harness or
connector in TCM
and ECM.Go to step 6.
5 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and ECM.
2) Connect the 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) Idle the engine.
6) Read the data of engine speed using Sub-
aru Select Monitor.
Display shows the engine speed signal value
sent from ECM.Is the revolution value same as
tachometer reading shown on
combination meter?Even if the
POWER indicator
light was blinking,
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
the harness or
connector in TCM
and ECM.Go to step 6.
6 CHECK POOR CONTACT.Is there poor contact in engine
speed signal circuit?Repair the poor
contact.Go to step 7.
7 CONFIRM DTC 11.Replace the ECM with a new
one. Does the DTC 11 appear
again, after memory has been
cleared?Replace the TCM.
trol Module
(TCM).>Replace the ECM.
Engine Control
Module (ECM).>

4AT(H4SO)-39
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion and TCM.
3) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B54) No. 20 — (B11) No. 12:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B54) No. 11 — (B11) No. 11:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 20 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 4.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 11 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 5.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
5 CHECK ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Connect the connectors to transmission
and TCM.
3) Turn the ignition switch to ON and start
engine.
4) Warm-up the transmission until ATF tem-
perature reaches to 80°C (176°F).
NOTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
5) Disconnect the connector from transmis-
sion.
6) Measure the resistance between transmis-
sion connector terminals.
Connector & terminal
(T4) No. 11 — No. 12:Is the resistance 275 — 375
Ω?Go to step 6.Replace the ATF
temperature sen-
sor.
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
6 CHECK ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to ON (engine
OFF).
2) Measure the resistance between transmis-
sion connector terminals.
Connector & terminal
(T4) No. 11 — No. 12:Does the resistance value
increase while ATF tempera-
ture decreases? Go to step 7.Replace the ATF
temperature sen-
sor.
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
7 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 9.Go to step 8.