2004 SUBARU FORESTER replace disc

4AT(H4DOTC)-55
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
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
(B55) No. 6 — (B11) No. 14: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 TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B55) No. 15 — (B11) No. 18:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B55) No. 6 — 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 TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B55) No. 15 — 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, and poor
contact in cou-
pling connector.
5 CHECK FRONT VEHICLE SPEED SENSOR.
Measure the resistance between transmission
connector receptacle’s terminals.
Connector & terminal
(T4) No. 14 — No. 18:Is the resistance 450 — 650
Ω?Go to step 6.Replace the front
vehicle speed sen-
sor. 55, Front Vehicle
Speed Sensor.>
6 PREPARE OSCILLOSCOPE.Do you have an oscilloscope? Go to step 9.Go to step 7.
7 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 10.Go to step 8.
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect all connectors.
2) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off floor.
3) Start the engine and set vehicle in 20 km/h
(12 MPH) condition.
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 clear-
ance procedure of on-board diagnostics system.

4) Measure the voltage between TCM con-
nector terminals.
Connector & terminal
(B55) No. 6 (+) — No. 15 (
−):Is the voltage more than AC 1
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
or harness may be
the cause. Repair
the harness or
connector in the
front vehicle speed
sensor circuit.Go to step 11.

4AT(H4DOTC)-58
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from stop light
switch.
3) Measure the resistance between stop light
switch connector.
Connector & terminal
No. 2 — No. 3:Is the resistance more than 1
MΩ?Go to step 3.Replace the stop
light switch.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND STOP LIGHT SWITCH.
1) Turn the ignition switch to ON.
2) Measure the voltage of harness between
TCM and chassis ground.
Connector & terminal
(B55) No. 20 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 4.Repair the short in
power supply cir-
cuit to harness
between TCM and
stop light switch.
4 INSPECT POOR CONTACT.Is there poor contact in the
stop light switch input signal
circuit?Repair poor con-
tact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-68
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
11 CHECK LOCK-UP DUTY SOLENOID (IN
TRANSMISSION).
1) Disconnect the transmission connector.
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 and transmission ground.
Connector & terminal
(AT12) No. 4 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 12.Replace control
valve body. to 4AT-61, Control
Valve Body.>
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. 12 — (AT12) No. 4: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. 12 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in lock-up duty
solenoid and trans-
mission.Repair the short
circuit in harness
between lock-up
duty solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4DOTC)-71
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Fully open the throttle.
2) Shift the select lever to “R” range. (engine
OFF)
3) Read the data of line pressure linear sole-
noid.Is the value 20 — 40%? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in line
pressure linear solenoid cir-
cuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK LINE PRESSURE LINEAR SOLE-
NOID (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 line pressure linear solenoid.
4) Measure the resistance between line pres-
sure linear solenoid connector and transmis-
sion ground.
Connector & terminal
(AT11) No. 2 — No. 4:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the con-
trol valve body.
Control Valve
Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LINE PRESSURE LIN-
EAR SOLENOID.
Measure the resistance of harness between
line pressure linear solenoid and transmission
connector.
Connector & terminal
(T4) No. 2 — (AT11) No. 4:
(T4) No. 1 — (AT11) No. 2:Is the resistance less than 1
Ω?Go to step 12.Repair the open cir-
cuit in harness
between line pres-
sure linear solenoid
and transmission
connector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LINE PRESSURE LIN-
EAR SOLENOID.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 1 — Transmission ground:
(T4) No. 2 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in line pressure
linear solenoid and
transmission.Repair the short
circuit in harness
between line pres-
sure linear sole-
noid and
transmission con-
nector. Step Check Yes No

4AT(H4DOTC)-74
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
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 transmission until ATF tem-
perature 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.
5) Stop the engine and turn ignition switch to
ON (engine OFF).
6) Shift the select lever to “P” or “N” range.
7) Read the data of low clutch duty solenoid
using Subaru Select Monitor.
 Low clutch duty solenoid is indicated in “%”.Is the value 100%? Go to step 8.Go to step 9.
8 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Turn the ignition switch to ON (engine
OFF).
2) Shift the select lever to “D” range.
3) Read the data of low clutch duty solenoid.Is the value 0%? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in low
clutch duty solenoid circuit?Repair the poor
contactReplace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK LOW CLUTCH 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 low clutch duty solenoid.
4) Measure the resistance between low clutch
duty solenoid connector and transmission
ground.
Connector & terminal
(AT12) No. 2 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the con-
trol valve body.
Control Valve
Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LOW CLUTCH DUTY
SOLENOID.
Measure the resistance of harness between
low clutch duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 4 — (AT12) No. 2:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between low clutch
duty solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4DOTC)-78
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
9 CHECK POOR CONTACT.Is there poor contact in 2-4
brake duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK 2-4 BRAKE 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 2-4 brake duty solenoid.
4) Measure the resistance of harness
between 2-4 brake duty solenoid connector
and transmission ground.
Connector & terminal
(AT12) No. 6 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the control
valve body. 4AT-61, Control
Valve Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
2-4 BRAKE DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between 2-
4 brake duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 3 — (AT12) No. 6:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between 2-4 brake
clutch duty sole-
noid and transmis-
sion connector.
12 CHECK HARNESS CONNECTOR BETWEEN
2-4 BRAKE DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 3 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in 2-4 brake duty
solenoid and trans-
mission.Repair the short
circuit harness
between 2-4 brake
duty solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4DOTC)-82
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
10 CHECK HIGH CLUTCH 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 high clutch duty solenoid.
4) Measure the resistance between high
clutch duty solenoid connector and transmis-
sion ground.
Connector & terminal
(AT12) No. 3 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the control
valve body. 4AT-61, Control
Valve Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
HIGH CLUTCH DUTY SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between
high clutch duty solenoid and transmission
connector.
Connector & terminal
(T4) No. 7 — (AT12) No. 3:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
HIGH CLUTCH DUTY SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 7 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in high clutch
duty solenoid and
transmission.Repair the short
circuit in harness
between high
clutch duty sole-
noid and transmis-
sion connector. Step Check Yes No

4AT(H4DOTC)-85
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Shift the select lever to “1” range.
2) Read the data of low & reverse duty sole-
noid.Is the value 61.5%? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in low &
reverse duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK LOW & REVERSE BRAKE 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 low & reverse brake duty solenoid.
4) Measure the resistance between low &
reverse brake duty solenoid connector and
transmission ground.
Connector & terminal
(AT12) No. 1 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the control
valve body. 4AT-61, Control
Valve Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LOW & REVERSE
BRAKE DUTY SOLENOID.
Measure the resistance of harness between
low & reverse brake duty solenoid and trans-
mission connector.
Connector & terminal
(T4) No. 6 — (AT12) No. 1:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between low &
reverse brake duty
solenoid and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LOW & REVERSE
BRAKE DUTY SOLENOID.
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
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in low & reverse
brake duty solenoid
and transmission.Repair the short
circuit in harness
between low &
reverse brake duty
solenoid and
transmission con-
nector. Step Check Yes No