2004 SUBARU FORESTER light

4AT(H4DOTC)-47
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the voltage of harness between TCM
connector and chassis ground.
Connector & terminal
(B55) No. 9 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 3.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
3 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).
N
OTE:
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. 15:Is the resistance 500 — 600
Ω?Go to step 4.Replace ATF tem-
perature sensor.
Control Valve
Body.>
4 CHECK ATF TEMPERATURE SENSOR.
Measure the resistance between transmission
connector terminals.
Connector & terminal
(T4) No. 11 — No. 15:Does the resistance value
increase when ATF tempera-
ture decreases? Go to step 5.Replace ATF tem-
perature sensor.
Control Valve
Body.>
5 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 7.Go to step 6.
6 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connector to transmission.
2) Warm-up the transmission until ATF tem-
perature is about 80°C (176°F).
N
OTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
3) Measure the voltage between TCM con-
nector terminal.
Connector & terminal
(B55) No. 9 (+) — No. 21 (
−):Is the voltage 1.5 — 1.9 V? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. Tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or contact
in ATF temperature
sensor and trans-
mission connector.Go to step 8.
7 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connector to transmission.
2) Turn the ignition switch to ON (engine
OFF).
3) Read the data of ATF temperature using
the Subaru Select Monitor. 4AT(H4DOTC)-15, OPERATION, Subaru
Select Monitor.>Does the ATF temperature
gradually decrease?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. Tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or contact
in ATF temperature
sensor and trans-
mission connector.Go to step 8. Step Check Yes No

4AT(H4DOTC)-50
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Disconnect the connector from TCM.
2) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B55) No. 7 — (B11) No. 5: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 between
TCM and transmission connector.
Connector & terminal
(B55) No. 16 — (B11) No. 10:Is the resistance less than 1
Ω?Go to step 4.Repair the open
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 16 — 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 HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 7 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 6.Repair the short
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
6 PREPARE OSCILLOSCOPE.Do you have an oscilloscope? Go to step 10.Go to step 7.
7 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 9.Go to step 8.
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Start the engine and shift select lever to “P”
or “N” range.
3) Measure the voltage between TCM con-
nector terminals.
Connector & terminal
(B55) No. 7 (+) — No. 16 (
−):Is the voltage more than AC 1
V?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 11.
9 CHECK INPUT SIGNAL FOR 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 and turn Sub-
aru Select Monitor switch to ON.
4) Start the engine.
5) Shift the select lever to “P” or “N” range.
6) Read the data of turbine speed using Sub-
aru Select Monitor.
 Compare the tachometer with Subaru Select
Monitor indications.Is the revolution value same as
the tachometer reading shown
on the combination meter?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 11. Step Check Yes No

4AT(H4DOTC)-51
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
10 CHECK INPUT SIGNAL FOR TCM USING
OSCILLOSCOPE.
1) Connect the connectors to TCM and trans-
mission.
2) Set the oscilloscope to TCM connector ter-
minals.
Connector & terminal
Positive probe; (B55) No. 7:
Earth lead; (B55) No. 16:
3) Start the engine and move select lever to
“P” or “N” range.Is the voltage more than AC 1
V?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 11.
11 CHECK POOR CONTACT.Is there poor contact in torque
converter turbine speed sensor
circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-52
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
E: DTC P0719 TORQUE CONVERTER/BRAKE SWITCH “B” CIRCUIT LOW
DTC DETECTING CONDITION:
Stop light switch malfunction or input signal open circuit.
TROUBLE SYMPTOM:
Gear is not shifted down when climbing hill.
WIRING DIAGRAM:
Step Check Yes No
1 CHECK OPERATION OF BRAKE LIGHT.
Depress the brake pedal.Does the brake light illumi-
nate?Go to step 2.Check the brake
light circuit.
2 CHECK TCM INPUT SIGNAL.
1) Depress the brake pedal.
2) Measure the voltage of harness between
TCM and stop light switch.
Connector & terminal
(B55) No. 20 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 5.Go to step 3.
AT-01844
B55
B65
E
2 3
SBF-1
SBF-2
NO.16
20
B55
B65
TCM
12 7
8956 34
10 11 12
19 20 2113 14 15 16
17 18 22 23 24
1234
BATTERY
STOP LIGHT
SWITCH
TO STOP LIGHT

4AT(H4DOTC)-53
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
stop light switch.
3) Measure the resistance of harness
between TCM and stop light switch.
Connector & terminal
(B55) No. 20 — (B65) No. 3:Is the resistance less than 1
Ω?Go to step 4.Repair the open
harness between
TCM and stop light
switch.
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND STOP LIGHT SWITCH.
Measure the resistance of harness between
TCM and chassis ground.
Connector & terminal
(B55) No. 20 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 5.Repair the short
circuit in harness
between TCM and
stop light switch.
5 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)-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)-56
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
9 CHECK FRONT VEHICLE SPEED SENSOR
USING OSCILLOSCOPE.
1) Connect all connectors.
2) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off ground.
3) Set the oscilloscope to TCM connector ter-
minals.
Connector & terminal
Positive probe; (B55) No. 6:
Earth lead; (B55) No. 15:
4) Start the engine, and drive the wheels
slowly.
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunctions. When AT control di-
agnosis is finished, perform the ABS memory
clearance procedure of on-board diagnostic sys-
tem.
5) Measure the signal voltage indicated on
oscilloscope.Is the voltage more than AC 4
V?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact or
harness may be the
cause. Repair the
harness or connec-
tor in front vehicle
speed sensor cir-
cuit.Go to step 11.
10 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect all connectors.
2) Connect the Subaru Select Monitor to data
link connector.
3) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off floor.
4) Turn the ignition switch to ON and turn Sub-
aru Select Monitor switch to ON.
5) Start the engine.
6) Read the data of vehicle speed using Sub-
aru Select Monitor.
 Compare the speedometer with Subaru
Select Monitor indications.
 Vehicle speed is indicated in “km/h” or
“MPH”.
7) Slowly increase the vehicle speed to 60 km/
h (37 MPH).
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.
Does the speedometer indica-
tion increase as Subaru Select
Monitor data increases?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor connec-
tor or harness may
be the cause.
Repair the harness
or connector in
front vehicle speed
sensor circuit.Go to step 11.
11 CHECK POOR CONTACT.Is there poor contact in front
vehicle speed sensor circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-57
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
G: DTC P0724 TORQUE CONVERTER/BRAKE SWITCH “B” CIRCUIT HIGH
DTC DETECTING CONDITION:
Stop light switch malfunction or open input signal circuit.
TROUBLE SYMPTOM:
Gear is not shifted down when climbing hill.
WIRING DIAGRAM:
Step Check Yes No
1 CHECK TCM INPUT SIGNAL.
1) Disconnect the harness connector from
TCM.
2) Measure the voltage of harness between
TCM and stop light switch.
Connector & terminal
(B55) No. 20 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 2.Go to step 4.
AT-01844
B55
B65
E
2 3
SBF-1
SBF-2
NO.16
20
B55
B65
TCM
12 7
8956 34
10 11 12
19 20 2113 14 15 16
17 18 22 23 24
1234
BATTERY
STOP LIGHT
SWITCH
TO STOP LIGHT