engine SUBARU FORESTER 2004 Service Repair Manual

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

4AT(H4SO)-113
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Shock occurs from 2nd to 3rd gear.TCM
 Throttle position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
High clutch
2-4 brake
 ATF deterioration
 Engine performance
 2-4 brake timing solenoid
Slippage occurs from 2nd to 3rd gear.TCM
 Throttle position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
High clutch
2-4 brake
 2-4 brake timing solenoid
Shock occurs from 3rd to 4th gear.TCM
 Throttle position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
 2-4 brake timing solenoid
2-4 brake
 ATF deterioration
 Engine performance
 Low clutch timing solenoid
 Low clutch
Slippage occurs from 3rd to 4th 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
Shock occurs when select lever is moved from “3” to “2” range.TCM
 Throttle position sensor
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
 2-4 brake duty solenoid
2-4 brake
 ATF deterioration
 2-4 brake timing solenoid
Shock occurs when select lever is moved from “D” to “1” range.TCM
 Throttle position sensor
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
 ATF deterioration
 2-4 brake duty solenoid
 2-4 brake timing solenoid
 Low clutch timing solenoid Symptom Problem parts

4AT(H4SO)-114
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Shock occurs when select lever is moved from “2” to “1” range.TCM
 Throttle position sensor
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
 Low & reverse clutch
 ATF deterioration
 2-4 brake duty solenoid
 2-4 brake timing solenoid
 Low clutch timing solenoid
Shock occurs when accelerator pedal is released at medium
speeds.TCM
 Throttle position sensor
 ATF temperature sensor
 Line pressure duty solenoid
 Control valve
 Lock-up damper
 Engine performance
 2-4 brake duty solenoid
 2-4 brake timing solenoid
 Low clutch timing solenoid
Vibration occurs during straight-forward operation.TCM
 Lock-up duty solenoid
 Lock-up facing
 Lock-up damper
HOLD switch
Vibration occurs during turns (tight corner “braking” phenomenon).TCM
 Front vehicle speed sensor
 Rear vehicle speed sensor
 Throttle position sensor
 ATF temperature sensor
 Transfer clutch
Transfer valve
 Transfer duty solenoid
 ATF deterioration
Harness
HOLD switch
Front wheel slippage occurs during standing starts.TCM
 Front vehicle speed sensor
FWD switch
 Throttle position sensor
 ATF temperature sensor
 Control valve
 Transfer clutch
Transfer valve
 Transfer pipe
 Transfer duty solenoid
Vehicle is not set in FWD mode.TCM
FWD switch
 Transfer clutch
Transfer valve
 Transfer duty solenoid
Select lever is hard to move. Select cable
 Select lever
 Detente spring
 Manual plate
Select lever is too hard to move (unreasonable resistance). Detente spring
 Manual plate Symptom Problem parts

4AT(H4DOTC)-6
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
5. OPERATION OF SELECT LEVER
Make sure there is no abnormal noise, dragging or
contact pattern in each select lever range.
WARNING:
Stop the engine while checking operation of se-
lect lever.
6. POWER SWITCH
Make sure that the POWER indicator light in com-
bination meter comes on, when turning the POW-
ER switch to ON.
7. HOLD SWITCH
Make sure that the HOLD indicator light in combina-
tion meter comes on, when turning the HOLD switch
to ON.
AT-00413
P
R
N
D
3
2
1
AT-00319
AT-00320

4AT(H4DOTC)-8
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Electrical Components Location
4. Electrical Components Location
A: LOCATION
1. CONTROL MODULE
 LHD MODEL
 RHD MODEL
(1) Engine control module (ECM) (3) Transmission control module
(TCM)(4) Data link connector
(2) AT diagnostic warning light
(POWER indicator light)
AT-00414
(1) (2)
(3) (4)
AT-00369 (2)
(4)
(1)
(3)

4AT(H4DOTC)-12
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Transmission Control Module (TCM) I/O Signal
5. Transmission Control Module (TCM) I/O Signal
A: ELECTRICAL SPECIFICATION
Check with ignition switch ON.
ItemConnector
No.Terminal No. Measuring conditions Voltage (V)Resistance
to chassis
ground (Ω)
Back-up power supply B5627
Ignition switch OFF 10 — 13 — 28
29
ACC power supply B56 16 Ignition switch ACC 10 — 13 —
Ignition power supplyB56 21
Ignition switch ON
(with engine OFF)10 — 13 —
B56 31
Inhibitor
switch“P” range
switchB55 5Select lever in “P” range Less than 1
—
Select lever in any other than
“P” range (except “N” range)More than 8
“N” range
switchB55 22Select lever in “N” range Less than 1
—
Select lever in any other
than “N” rangeMore than 8
“R” range
switchB55 14Select lever in “R” range Less than 1
—
Select lever in any other
than “R” rangeMore than 8
“D” range
switchB55 4Select lever in “D” range Less than 1
—
Select lever in any other
than “D” rangeMore than 8
“3” range
switchB54 16Select lever in “3” range Less than 1
—
Select lever in any other
than “3” rangeMore than 8
“2” range
switchB54 4Select lever in “2” range Less than 1
—
Select lever in any other
than “2” rangeMore than 8
“1” range
switchB54 10Select lever in “1” range Less than 1
—
Select lever in any other
than “1” rangeMore than 8
Brake switch B55 20Brake pedal depressed. More than 10.5
—
Brake pedal released. Less than 1
AT-01107
B54B55B56
1 2 7
8 9 5 6
3 4
10 11 12
19 20 21 13 14 15 16
17 18 22 23
241 2 7 8 95634
10 11 12 19 20 21
29 30 3113 14 15 16 17
27
28 18
22 23 24 25 26 1 2 3
8 9 104
11 12
13 14 15
165 6
7
17To
ToTo

4AT(H4DOTC)-13
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Transmission Control Module (TCM) I/O Signal
Accelerator pedal position
sensor (2.5 L model)
B55 19Throttle fully closed. More than 0.2
—
Throttle position sensor (2.0
L model)Throttle fully open. Less than 4.6
Accelerator pedal position
sensor power supply (2.5 L
model)B55 10 Ignition switch ON
(with engine OFF)Approx. 5 —
Throttle position sensor
power supply (2.0 L model)
ATF temperature sensor B55 21ATF temperature 20°C
(68°F)3.5 — 4.3 3.9 k — 4.7 k
ATF temperature 80°C
(176°F)1.5 — 1.9 500 — 600
Rear vehicle speed sensor B55 24Vehicle speed at least
20 km/h (12 MPH)More than 2 (AC range) —
Front vehicle speed sensor B55 6Vehicle stopped. 0
450 — 750
Vehicle speed at least
20 km/h (12 MPH)More than 1 (AC range)
Torque converter turbine
speed sensorB55 7Engine idling after warm-
up. (“D” range)0
450 — 750
Engine idling after warm-
up. (“N” range)More than 1 (AC range)
Vehicle speed output signal B56 1Vehicle speed at least
10 km/h (6 MPH)Less than 1←
→More than 4—
Engine speed signal B55 13Ignition switch ON
(with engine OFF)Less than 1
—
Ignition switch ON
(with engine ON)More than 5
(AC range)
Line pressure linear solenoid B56 20Ignition switch ON
(with engine OFF)
“R” range and throttle fully
closed after warm-up.5 — 7
4.0 — 8.0
Ignition switch ON
(with engine OFF)
“R” range and throttle fully
open after warm-up.3 — 5
Lock-up duty solenoid B56 5When lock up occurs. More than 10.5
2.0 — 4.5
When lock up is released. Less than 1
Transfer duty solenoid B56 4“P” or “N” range Less than 1
2.0 — 4.5
Throttle fully open and with
select lever in 1st gear.More than 10.5
2-4 brake duty solenoid B56 6“P” or “N” range More than 10.5
2.0 — 4.5
2nd or 4th gear Less than 1
High clutch duty solenoid B56 83rd or 4th gear Less than 1
2.0 — 4.5
“P” or “N” range More than 10.5
Low clutch duty solenoid B56 91st or 2nd gear Less than 1
2.0 — 4.5
“P” or “N” range More than 10.5
Low & reverse duty solenoid B56 7“P” or “N” range More than 10.5
2.0 — 4.5
“1” range More than 5
HOLD switch B54 2HOLD switch ON Less than 1
—
HOLD switch OFF More than 10.5 Check with ignition switch ON.
ItemConnector
No.Terminal No. Measuring conditions Voltage (V)Resistance
to chassis
ground (Ω)

4AT(H4DOTC)-15
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Subaru Select Monitor
6. Subaru Select Monitor
A: OPERATION
1. READ DIAGNOSTIC TROUBLE CODE
1) Prepare the Subaru Select Monitor kit.
2) Connect the diagnosis cable to Subaru Select
Monitor.
3) Insert the cartridge into Subaru Select Monitor.
General Description.>
4) Connect the Subaru Select Monitor to data link
connector.
(1) Data link connector located in the lower por-
tion of instrument panel (on driver’s side).
(2) Connect the diagnosis cable to data link con-
nector.
NOTE:
Do not connect scan tools except for Subaru Select
Monitor.5) Turn the ignition switch to ON (engine OFF) and
Subaru Select Monitor switch to ON.
6) On the «Main Menu» display screen, select the
{Each System Check} and press the [YES] key.
7) On the «System Selection Menu» display screen,
select the {Transmission Control System} and press
the [YES] key.
8) Press the [YES] key after the information of trans-
mission type is displayed.
9) On the «Transmission Diagnosis» display screen,
select the {Diagnostic Code(s) Display} and press
the [YES] key.
NOTE:
 For details concerning operation procedure, re-
fer to the “SUBARU SELECT MONITOR OPERA-
TION MANUAL”.
 For details concerning the DTC, refer to the DTC
LIST. Trouble Code (DTC).>
2. READ CURRENT DATA
1) On the «Main Menu» display screen, select the
{Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen,
select the {Transmission Control System} and press
the [YES] key.
3) Press the [YES] key after the information of trans-
mission type is displayed.
4) On the «Transmission Diagnosis» display screen,
select the {Current Data Display & Save} and press
the [YES] key.
5) On the «Transmission Diagnosis» display screen,
select the {Data Display} and press the [YES] key.
AT-00338
AT-00339
AT-00422
(A) POWER switch
(A)
AT-00341

4AT(H4DOTC)-16
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Subaru Select Monitor
6) Using the scroll key, move the display screen up or down until desired data is shown.
A list of the support data is shown in the following table.
NOTE:
For detailed operation procedure, refer to the “SUBARU SELECT MONITOR OPERATION MANUAL”.
Contents Display Unit of measure
Battery voltage Battery Voltage V
Rear vehicle speed sensor signal Rear Wheel Speed km/h or MPH
Front vehicle speed sensor signal Front Wheel Speed km/h or MPH
Engine speed signal Engine Speed rpm
ATF temperature signal ATF Temp.°C or °F
Throttle position signal Throttle Sensor Voltage V
Gear position Gear Position —
Line pressure control duty ratio Line Pressure Duty Ratio %
Lock up clutch control duty ratio Lock Up Duty Ratio %
Transfer clutch control duty ratio Transfer Duty Ratio %
Power supply for throttle position sensor Throttle Sensor Power V
Torque converter turbine speed signal Turbine Revolution Speed rpm
2-4 brake timing pressure control duty ratio Brake Clutch Duty Ratio %
Low clutch duty ratio L/C Duty %
High clutch duty ratio H/C Duty %
Low & reverse brake duty ratio L&R/B Duty %
Throttle position Throttle position %
Accelerator pedal position Accel. Opening Angle %
Cruise control system Cruise Control Signal ON or OFF
Automatic transmission fluid temperature lamp ATF Temperature Lamp ON or OFF
Stop light switch signal Stop Light Switch ON or OFF
ABS signal ABS Signal ON or OFF
Parking range signal P Range Signal ON or OFF
Neutral range signal N Range Signal ON or OFF
Reverse range signal R Range Signal ON or OFF
Drive range signal D Range Signal ON or OFF
3rd range signal 3rd Range Signal ON or OFF
2nd range signal 2nd Range Signal ON or OFF
1st range signal 1st Range Signal ON or OFF
AT diagnosis indicator lamp Diagnosis Lamp ON or OFF
POWER switch signal POWER Switch ON or OFF
HOLD switch signal HOLD Switch ON or OFF
FWD switch signal FWD SW ON or OFF
Shift lock solenoid signal Shift Lock solenoid ON or OFF

4AT(H4DOTC)-17
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Subaru Select Monitor
3. CLEAR MEMORY MODE
1) On the «Main Menu» display screen, select the
{2. Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen,
select the {Transmission Control System} and press
the [YES] key.
3) Press the [YES] key after the information of
transmission type is displayed.
4) On the «Transmission Diagnosis» display screen,
select the {Clear Memory} and press the [YES] key.
5) When the “Done” is shown on display screen,
turn the Subaru Select Monitor and ignition switch
to OFF.
NOTE:
 For details concerning operation procedure, refer
to the SUBARU SELECT MONITOR OPERATION
MANUAL.
 When {Clear Memory 2} is selected and executed,
DTC and learned control memory is cleared. If Clear
Memory 2 is performed, execute the learning con-
trol. OF LEARNING CONTROL, OPERATION, Subaru
Select Monitor.>
4. FACILITATION OF LEARNING CON-
TROL
1) Shift the select lever to “P” range, and apply
parking brake.
2) Lift-up the vehicle.
3) Connect the Subaru Select Monitor to data link
connector, and then turn the ignition switch to ON.
4) Perform the {Clear Memory 2} using Subaru Select
Monitor. ORY MODE, OPERATION, Subaru Select Monitor.>
5) Using Subaru Select Monitor, check that the DTC
is not output. AGNOSTIC TROUBLE CODE, OPERATION, Sub-
aru Select Monitor.>
6) Warm-up the engine until the ATF temperature
which is displayed on the Subaru Select Monitor is
within 60 — 90°C (140 — 194°F). 4AT(H4DOTC)-15, READ CURRENT DATA, OP-
ERATION, Subaru Select Monitor.>
7) Shift the select lever to “R” range.
8) Turn all switches including headlight, air condi-
tioner, seat heater, rear defogger and etc. to OFF.
9) Turn the ignition switch to OFF.
10) Depress the brake pedal fully until the facilitation
of learning control is completed when the “Communi-
cation Failed!” is displayed on Subaru Select Monitor.
11) Turn the ignition switch to ON.
12) Check that the Subaru Select Monitor is re-
turned to normal operation.
13) Shift the select lever to “P” range, and then wait
for more than 3 seconds.14) Shift the select lever to “R” range, and then wait
for more than 3 seconds.
15) Shift the select lever to “N” range, and then wait
for more than 3 seconds.
16) Shift the select lever to “D” range, and then wait
for more than 3 seconds.
17) Shift the select lever to “N” range, and then wait
for more than 3 seconds.
18) Slightly depress the accelerator pedal fully.
19) Slightly release the accelerator pedal fully.
20) Start the engine, and idle it.
21) Shift the select lever to “D” range.
22) Start the facilitation of learning control. At this
time, the POWER indicator light in combination meter
blinks at 2 Hz. When the POWER indicator light does
not blink, turn the ignition switch to OFF and repeat
the procedures from step 4). When the POWER indi-
cator light which blinking at 2 Hz changes to blink at
0.5 Hz, facilitation of learning control is completed.
NOTE:
When blinking of POWER indicator light changes
from 2 Hz to 4 Hz during facilitation of learning con-
trol, repeat the procedure from step 4).
23) Shift the select lever to “N” range, and then turn
the ignition switch to OFF.
24) Shift the select lever to the “P” range, and then
complete the facilitation of learning control.