2004 SUBARU FORESTER automatic transmission

4AT(H4SO)-74
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
N: DTC 77 LOCK-UP DUTY SOLENOID
DTC DETECTING CONDITION:
The output signal circuit of lock-up duty solenoid is open or shorted.
TROUBLE SYMPTOM:
No “lock-up” (after engine warm-up).
WIRING DIAGRAM:
AT-00589

7
TRANSMISSION
B54TCM
AT 3
13T4
B11
LOCK-UP
DUTY
SOLENOID
B54
12
789 56 3410 11 12
19 20 2113 14 15 16 17 18
22
23
24
B11
125678
131415169101112
34
17181920

4AT(H4SO)-75
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK DTC.Do multiple DTCs appear in
the on-board diagnostics test
mode?Go to another
DTC.Go to step 2.
2 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
(B54) No. 7 — (B11) No. 13: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 TRANSMISSION.
Measure the resistance of harness connector
between TCM and chassis ground.
Connector & terminal
(B54) No. 7 — 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 LOCK-UP DUTY SOLENOID.
Measure the resistance between transmission
connector receptacle’s terminals.
Connector & terminal
(T4) No. 13 — No. 16:Is the resistance 10 — 17 Ω? Go to step 5.Go to step 11.
5 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 8.Go to step 6.
6 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up the vehicle and place rigid rack.
N
OTE:
Raise all wheels off ground.
3) Start the engine and warm-up the transmis-
sion until ATF temperature is above 80°C
(176°F).
NOTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
4) Move the selector lever to “D” range and
slowly increase vehicle speed to 60 km/h (37
MPH). Wheels will lock-up.
NOTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>
5) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 7 (+) — Chassis ground (
−):Is the voltage more than 8.5 V? Go to step 7.Go to step 10.

4AT(H4SO)-76
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Return the engine to idling speed and move
select lever to “N” range.
2) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 7 (+) — Chassis ground (
−):Is the voltage less than 0.5 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 transmission.Go to step 10.
8 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up the vehicle and place rigid rack.
N
OTE:
Raise all wheels off ground.
3) Connect the Subaru Select Monitor to data
link connector.
4) Start the engine and turn Subaru Select
Monitor switch to ON.
5) Start the engine and warm-up the transmis-
sion until ATF temperature is above 80°C
(176°F).
N
OTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
6) Read the data of lock-up duty solenoid
using Subaru Select Monitor.
 Lock-up duty solenoid is indicated in “%”.
7) Move the selector lever to “D” range and
slowly increase vehicle speed to 60 km/h (37
MPH). Wheels will lock-up.
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>Is the value 95%? Go to step 9.Go to step 10.
9 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Return the engine to idling speed and move
selector lever to “N” range.
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>
2) Read the data of lock-up duty solenoid
using Subaru Select Monitor.Is the value 5%? 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 transmission.Go to step 10. Step Check Yes No

4AT(H4SO)-77
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
10 CHECK POOR CONTACT.Is there poor contact in lock-up
duty solenoid circuit?Repair poor con-
tact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
11 CHECK LOCK-UP DUTY SOLENOID (IN
TRANSMISSION).
1) Remove the transmission connector from
bracket.
2) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
3) Remove the oil pan and disconnect con-
nector from lock-up duty solenoid.
4) Measure the resistance between lock-up
duty solenoid connector and transmission
ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 10 — 17 Ω? Go to step 12.Replace the lock-
up duty solenoid.
Shift Solenoids,
Duty Solenoids
and ATF Tempera-
ture Sensor.>
12 CHECK HARNESS CONNECTOR BETWEEN
LOCK-UP DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
lock-up duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 13 — (AT3) No. 1:Is the resistance less than 1
Ω?Go to step 13.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
13 CHECK HARNESS CONNECTOR BETWEEN
LOCK-UP DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 13 — Transmission ground:Is the resistance more than 1
MΩ?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 lock-
up duty solenoid
and transmission.Repair the short
circuit in harness
between lock-up
duty solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4SO)-78
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
O: DTC 79 TRANSFER DUTY SOLENOID
DTC DETECTING CONDITION:
The output signal circuit of transfer duty solenoid is open or shorted.
TROUBLE SYMPTOM:
Tight corner braking phenomenon is occurred.
WIRING DIAGRAM:
Step Check Yes No
1 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
(B54) No. 6 — (B11) No. 6:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
AT-00590
-
6
TRANSMISSION
B54TCM
AT 4
6T4
B11
TRANSFER
DUTY
SOLENOID
B54
12
789 56 3410 11 12
19 20 2113 14 15 16 17 18
22
23
24
B11
125678
131415169101112
34
17181920

4AT(H4SO)-79
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance harness connector
between TCM and chassis ground.
Connector & terminal
(B54) No. 6 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
3 CHECK TRANSFER DUTY SOLENOID.
Measure the resistance between transmission
connector and transmission terminals.
Connector & terminal
(T4) No. 6 — No. 16:Is the resistance 10 — 17 Ω? Go to step 4.Go to step 10.
4 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 7.Go to step 5.
5 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Turn the ignition switch to ON (engine OFF).
3) Move the select lever to “P” range.
4) Throttle is fully closed.
5) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 6 (+) — Chassis ground (
−):Is the voltage more than 8.5 V? Go to step 6.Go to step 9.
6 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Move the select lever to “D” range.
2) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 6 (+) — Chassis ground (
−):Is the voltage 3.0 — 6.0 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 transmission.Go to step 9.
7 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON (engine OFF)
and turn Subaru Select Monitor switch to ON.
4) Move the select lever to “D” range with throt-
tle fully open (vehicle speed 0 km/h (0 MPH)).
5) Read data of transfer duty solenoid using
Subaru Select Monitor.
 Transfer duty solenoid is indicated in “%”.Is the value 80 — 95%? Go to step 8.Go to step 9. Step Check Yes No

4AT(H4SO)-80
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Move the select lever to “N” range with
throttle fully closed (vehicle speed 0 km/h or 0
MPH).
2) Read the data of transfer duty solenoid
using Subaru Select Monitor.
 Transfer duty solenoid is indicated in “%”.Is the value 5 — 10%? 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 transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in transfer
duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK TRANSFER DUTY SOLENOID (IN
TRANSMISSION).
1) Lift-up the vehicle and place rigid rack.
NOTE:
Raise all wheels off ground.
2) Drain the automatic transmission fluid.
CAUTION:
Do not drain the automatic transmission flu-
id until it cools down.
3) Remove the extension case and disconnect
connector from transfer duty solenoid.
4) Measure the resistance between transfer
duty solenoid connector and transmission
ground.
Connector & terminal
(AT4) No. 1 — Transmission ground:Is the resistance 10 — 17 Ω? Go to step 11.Replace the trans-
fer duty solenoid.
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSFER DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transfer duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 6 — (AT4) No. 1:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between transfer
duty solenoid and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSFER DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 6 — Transmission ground:Is the resistance more than 1
MΩ?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
contact in transfer
duty solenoid and
transmission.Repair the short
circuit in harness
between transfer
duty solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4SO)-81
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
P: DTC 93 REAR VEHICLE SPEED SENSOR
DTC DETECTING CONDITION:
The input signal circuit of TCM is open or shorted.
TROUBLE SYMPTOM:
 No lock-up.
 Tight corner braking phenomenon is occurred.
WIRING DIAGRAM:
AT-01828
19
20
B11
B299
T4
TCMB55 B:
B24
A19
SHIELD AND
SENSOR GROUND
JOINT CONNECTOR
LHD: LHD MODEL
: RHD MODEL
REAR VEHICLE
B55
123 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18
19 20 21 22 23 24
B11
12 34
5678
9
13 14 15
20 19 1716 10 11 12
18
SPEED SENSOR
B54
1234 5 6 7 8 9
10 11 12 13 14 15 16 17 18
19 20 21 22 23 24
B299
12345678
B54 A:
RHD
61
2
RHD 8
LHD3
7
A:
B: