2004 SUBARU FORESTER oil temperature

4AT(H4SO)-16
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Transmission Control Module (TCM) I/O Signal
(1) Transmission control module
(TCM)(17) “P” range indicator light (35) Torque control signal 2
(18) “P” range switch (36) Torque control signal 1
(2) Cruise control module (19) “R” range indicator light (37) Intake manifold pressure signal
(3) ABS control module (20) “R” range switch (38) AT diagnostics signal
(4) Ignition switch (21) “N” range indicator light (39) Engine control module (ECM)
(5) Brake switch (22) “N” range switch (40) ATF temperature sensor
(6) Brake light (23) “D” range indicator light (41) Torque converter turbine speed
sensor
(7) Battery (24) “D” range switch
(8) Combination meter (Speedome-
ter circuit)(25) “3” range indicator light (42) Rear vehicle speed sensor
(26) “3” range switch (43) Front vehicle speed sensor
(9) AT OIL TEMP warning light (27) “2” range indicator light (44) Shift solenoid 1
(10) FWD indicator light (28) “2” range switch (45) Shift solenoid 2
(11) POWER indicator light (29) “1” range indicator light (46) 2-4 brake timing solenoid
(12) FWD switch (30) “1” range switch (47) Line pressure duty solenoid
(13) POWER switch (31) Data link connector (48) 2-4 brake duty solenoid
(14) Kick-down switch (32) Throttle position sensor (49) Lock-up duty solenoid
(15) Hold indicator light (33) Engine speed signal (50) Low clutch timing solenoid
(16) HOLD switch (34) Torque control cut signal (51) Transfer duty solenoid

4AT(H4SO)-57
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 22 — 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 SHIFT SOLENOID 1.
Measure the resistance between transmission
connector terminals.
Connector & terminal
(T4) No. 1 — No. 16:Is the resistance 10 — 16 Ω? Go to step 4.Go to step 7.
4 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 “D” range.
4) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 22 (+) — Chassis ground (
−):Is the voltage more than 9 V? Go to step 5.Go to step 6.
5 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Turn the HOLD mode switch to ON.
2) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 22 (+) — Chassis ground (
−):Is the voltage less than 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
of the connector or
harness may be
the cause. Repair
the harness or
contact in TCM.Go to step 6.
6 CHECK POOR CONTACT.Is there poor contact in shift
solenoid 1 circuit?Repair poor con-
tact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
7 CHECK SHIFT SOLENOID 1 (IN TRANSMIS-
SION).
1) Remove the transmission connector from
bracket.
2) Lift-up or raise the vehicle and support with
rigid rack.
NOTE:
Raise all wheels off ground.
3) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
4) Remove the oil pan, and disconnect con-
nector from shift solenoid 1.
5) Measure the resistance between shift sole-
noid 1 connector and transmission ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 10 — 16 Ω? Go to step 8.Replace the shift
solenoid 1. to 4AT-71, Shift
Solenoids, Duty
Solenoids and ATF
Temperature Sen-
sor.> Step Check Yes No

4AT(H4SO)-61
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK SHIFT SOLENOID 2 (IN TRANSMIS-
SION).
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 shift solenoid 2.
4) Measure the resistance between shift sole-
noid 2 connector and transmission ground.
Connector & terminal
No. 1 — Transmission ground:Is the resistance 10 — 16 Ω? Go to step 7.Replace the shift
solenoid 2 assem-
bly. 71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
7 CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 2 AND TRANSMISSION.
Measure the resistance of harness between
shift solenoid 2 and transmission connector.
Connector & terminal
(AT6) No. 1 — (T4) No. 2:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between shift sole-
noid 2 and trans-
mission connector.
8 CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 2 AND TRANSMISSION.
Measure the resistance of harness between
shift solenoid 2 connector and transmission
ground.
Connector & terminal
(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 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 shift
solenoid 2 and
transmission.Repair the short
circuit harness
between shift sole-
noid 2 and trans-
mission connector. Step Check Yes No

4AT(H4SO)-64
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK LOW CLUTCH TIMING SOLENOID
(IN TRANSMISSION).
1) Remove the transmission connector from
bracket.
2) Lift-up or raise the vehicle and support with
rigid rack.
N
OTE:
Raise all wheels off ground.
3) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
4) Remove the oil pan, and disconnect con-
nector from low clutch timing solenoid.
5) Measure the resistance between low clutch
timing solenoid connector and transmission
ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 10 — 16 Ω? Go to step 8.Replace the low
clutch timing sole-
noid. 71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
8 CHECK HARNESS CONNECTOR BETWEEN
LOW CLUTCH TIMING SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between
low clutch timing solenoid and transmission
connector.
Connector & terminal
(AT9) No. 1 — (AT4) No. 3:Is the resistance less than 1
Ω?Go to step 9.Repair the open
circuit in harness
between low clutch
timing solenoid
and transmission
connector.
9 CHECK HARNESS CONNECTOR BETWEEN
LOW CLUTCH TIMING SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between
low clutch timing solenoid connector and trans-
mission 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 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 low
clutch timing sole-
noid and transmis-
sion.Repair the short
circuit harness
between low clutch
timing solenoid
and transmission
connector. Step Check Yes No

4AT(H4SO)-67
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK POOR CONTACT.Is there poor contact in 2-4
brake timing solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
7 CHECK 2-4 BRAKE TIMING SOLENOID (IN
TRANSMISSION).
1) Remove the transmission connector from
bracket.
2) Lift-up or raise the vehicle and support with
rigid rack.
N
OTE:
Raise all wheels off ground.
3) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
4) Remove the oil pan, and disconnect con-
nector from 2-4 brake timing solenoid.
5) Measure the resistance between 2-4 brake
timing solenoid connector and transmission
ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 10 — 16 Ω? Go to step 8.Replace the 2-4
brake timing sole-
noid. 71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
8 CHECK HARNESS CONNECTOR BETWEEN
2-4 BRAKE TIMING SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between 2-
4 brake timing solenoid and transmission con-
nector.
Connector & terminal
(AT8) No. 1 — (T4) No. 4:Is the resistance less than 1
Ω?Go to step 9.Repair the open
circuit in harness
between 2-4 brake
timing solenoid
and transmission
connector.
9 CHECK HARNESS CONNECTOR BETWEEN
2-4 BRAKE TIMING SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between 2-
4 brake timing solenoid connector and trans-
mission ground.
Connector & terminal
(T4) No. 4 — 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 2-4
brake timing sole-
noid and transmis-
sion.Repair the short
circuit harness
between 2-4 brake
timing solenoid
and transmission
connector. Step Check Yes No

4AT(H4SO)-70
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Turn the ignition switch to ON (engine
OFF).
2) Throttle is fully open.
3) Read the data of line pressure duty sole-
noid using Subaru Select Monitor.Is the value less than 25%? 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 trans-
mission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in line
pressure duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK LINE PRESSURE 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 line pressure duty solenoid.
4) Measure the resistance between line pres-
sure duty solenoid connector and transmission
ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the line
pressure duty
solenoid. 4AT-71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LINE PRESSURE
DUTY SOLENOID.
Measure the resistance of harness between
line pressure duty solenoid and transmission
connector.
Connector & terminal
(T4) No. 5 — (AT2) No. 1:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between line pres-
sure duty solenoid
and transmission
connector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LINE PRESSURE
DUTY SOLENOID.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 5 — 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 line
pressure duty
solenoid and
transmission.Repair the short
circuit in harness
between line pres-
sure duty solenoid
and transmission
connector. Step Check Yes No

4AT(H4SO)-73
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Turn the ignition switch to ON (engine
OFF).
2) Throttle is fully open.
3) Read the data of 2-4 brake duty solenoid
using Subaru Select Monitor.Is the value less than 25%? 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 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 between 2-4 brake
duty solenoid connector and transmission
ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the 2-4
brake duty sole-
noid. 71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND 2-4 BRAKE DUTY SO-
LENOID.
Measure the resistance of harness between 2-
4 brake duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 9 — (AT7) No. 1:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between 2-4 brake
duty solenoid and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND 2-4 BRAKE DUTY SO-
LENOID.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 9 — 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 line
pressure duty
solenoid and
transmission.Repair the short
circuit in harness
between 2-4 brake
duty solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4SO)-112
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
No shift occurs from 3rd to 4th gear.TCM
 Shift solenoid 1
 ATF temperature sensor
 Control valve
2-4 brake
Engine brake is not effected when select lever is in “3” range. Inhibitor switch
TCM
 Throttle position sensor
 Control valve
Engine brake is not effected when select lever is in “3” or “2”
range. Control valve
Engine brake is not effected when select lever is in “1” range. Control valve
 Low & reverse brake
Shift characteristics are erroneous. Inhibitor switch
TCM
 Front vehicle speed sensor
 Rear vehicle speed sensor
 Throttle position sensor
 Control valve
 Ground earth
No lock-up occurs.TCM
 Throttle position sensor
 ATF temperature sensor
 Control valve
 Lock-up facing
 Engine speed signal
Parking brake is not effected.  Select cable
 Select lever
 Parking mechanism Shift lever cannot be moved or is hard to move from “P” range.
ATF spurts out.  ATF level too high
Differential oil spurts out.  Differential gear oil too high
Differential oil level changes excessively. Seal pipe
 Double oil seal
Odor is produced from ATF supply pipe.High clutch
2-4 brake
 Low & reverse clutch
 Reverse clutch
 Lock-up facing
 ATF deterioration
Shock occurs from 1st to 2nd gear.TCM
 Throttle position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
2-4 brake
 ATF deterioration
 Engine performance
 2-4 brake timing solenoid
Slippage occurs from 1st to 2nd gear.TCM
 Throttle position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
2-4 brake
 2-4 brake timing solenoid
High clutch Symptom Problem parts