2004 SUBARU FORESTER automatic transmission

4AT(H4DOTC)-125
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
3 CHECK KICK-DOWN SWITCH GROUND
LINE.
1) Disconnect the connector from kick-down
switch.
2) Measure the resistance of harness connector
between kick-down switch and chassis ground.
Connector & terminal
(B129) No. 1 — Chassis ground:Is the resistance less than 1
Ω?Go to step 4.Repair the open cir-
cuit in harness
between kick-down
switch and TCM.
4 CHECK KICK-DOWN SWITCH.
Measure the resistance for kick-down switch
when depressing the accelerator pedal.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 1
Ω?Go to step 5.Replace the kick-
down switch. to SP(H4SO)-4,
Accelerator
Pedal.>
5 CHECK KICK-DOWN SWITCH.
Measure the resistance for kick-down switch
when pressing the accelerator pedal.
Te r m i n a l s
No. 1 — No. 2:Is the resistance more than 1
MΩ?Go to step 6.Replace the kick-
down switch.
6 CHECK HARNESS CONNECTOR BETWEEN
TCM AND KICK-DOWN SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from kick-down
switch.
3) Measure the resistance of harness connec-
tor between TCM and kick-down switch.
Connector & terminal
(B54) No. 11 — (B129) No. 2:Is the resistance less than 1
Ω?Go to step 7.Repair the open
circuit in harness
between TCM and
kick-down switch.
7 CHECK HARNESS CONNECTOR BETWEEN
TCM AND KICK-DOWN SWITCH.
Measure the resistance of harness connector
between TCM connector and chassis ground.
Connector & terminal
(B54) No. 11 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 8.Repair the short
circuit in harness
between TCM and
chassis ground.
8 CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to kick-down switch.
3) Turn the ignition switch to ON (engine OFF).
4) Measure the signal voltage for TCM when
not depressing the accelerator pedal.
Connector & terminal
(B55) No. 11 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 9.Go to step 10.
9 CHECK INPUT SIGNAL FOR TCM.
Measure the signal voltage for TCM when press-
ing the accelerator pedal.
Connector & terminal
(B55) No. 11 (+) — Chassis ground (
−):Is the voltage more than 6.5 V? A temporary poor
contact of the con-
nector and har-
ness may be the
cause. Repair the
harness and con-
nector in TCM.Go to step 10.
10 CHECK POOR CONTACT.Is there poor contact? Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-126
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
15.Symptom Related Diagnostic
A: INSPECTION
Symptom Problem parts
Starter does not rotate when select lever is in “P” or “N” range,
starter rotates when select lever is in “R”, “D”, “3” or “2” range. Inhibitor switch
 Select cable
 Select lever
 Starter motor and harness
Abnormal noise when select lever is in “P” or “N” range. Strainer
 Transfer duty solenoid
 Oil pump
Drive plate
 ATF level too high or too low
Hissing noise occurs during standing start. Strainer
 ATF level too high or too low
Noise occurs while driving in “D1”.  Final gear
 Planetary gear
 Reduction gear
 Differential gear oil level too high or too low Noise occurs while driving in “D2”.
Noise occurs while driving in “D3”. Final gear
 Low & reverse brake
 Reduction gear
 Differential gear oil level too high or too low
Noise occurs while driving in “D4”. Final gear
 Low & reverse brake
 Planetary gear
 Reduction gear
 Differential gear oil level too high or too low
Engine stalls while shifting from “1” range to another. Control valve
 Lock-up damper
 Engine performance
 Input shaft
Vehicle moves when select lever is in “N” range. Select cable
 Inhibitor switch
TCM
 Low clutch
Shock occurs when select lever is shifted from “N” to “D” range. Accelerator pedal position sensor
 ATF temperature sensor
 Line pressure linear solenoid
 Low clutch duty solenoid
 Low clutch
TCM
Harness
 Control valve
 ATF deterioration
Excessive time lag occurs when select lever is shifted from “N”
to “D” range. Control valve
 Low clutch
 Line pressure duty solenoid
 Seal ring
 Front gasket of transmission case
Shock occurs when select lever is shifted from “N” to “R” range. Accelerator pedal position sensor
 ATF temperature sensor
 Line pressure linear solenoid
TCM
Harness
 Control valve
 ATF deterioration

4AT(H4DOTC)-127
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Excessive time lag occurs when select lever is shifted from “N”
to “R” range. Control valve
 Low & reverse clutch
 Reverse clutch
 Line pressure linear solenoid
 Seal ring
 Front gasket of transmission case
Vehicle does not start in any shift range (engine stalls). Parking brake mechanism
 Planetary gear
Vehicle does not start in any shift range (engine revving up). Strainer
 Line pressure linear solenoid
 Control valve
 Drive pinion
 Hypoid gear
Axle shaft
 Differential gear
 Oil pump
 Input shaft
 Output shaft
 Planetary gear
Drive plate
 ATF level too low
 Front gasket of transmission case
Vehicle does not start in “R” range only (engine revving up). Select cable
 Select lever
 Line pressure linear solenoid
 Control valve
 Low & reverse clutch
 Reverse clutch
Vehicle does not start in “R” range only (engine stalls). Low clutch
2-4 brake
 Planetary gear
 Parking brake mechanism
Vehicle does not start in “D”, “3” range only (engine revving up). Low clutch
 One-way clutch
Vehicle does not start in “D”, “3” or “2” range only (engine rev-
ving up).Low clutch
Vehicle does not start in “D”, “3” or “2” range only (engine
stalls).Reverse clutch
Vehicle starts in “R” range only (engine revving up).  Control valve
Acceleration during standing starts is poor (high stall rpm). Control valve
 Low clutch
 Reverse clutch
 ATF level too low
 ATF deterioration
 Front gasket of transmission case
 Differential gear oil level too high or too low
Acceleration during standing starts is poor (low stall rpm). Oil pump
 Torque converter one-way clutch
 Engine performance
Acceleration is poor when select lever is in “D”, “3” or “2” range
(normal stall rpm).TCM
 Control valve
High clutch
2-4 brake
 Planetary gear
Acceleration is poor when select lever is in “R” (normal stall
rpm). Control valve
High clutch
2-4 brake
 Planetary gear Symptom Problem parts

4AT(H4DOTC)-128
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
No shift occurs from 1st to 2nd gear.TCM
 Rear vehicle speed sensor
 Front vehicle speed sensor
 Throttle position sensor
 Control valve
2-4 brake
No shift occurs from 2nd to 3rd gear.TCM
 Control valve
High clutch
No shift occurs from 3rd to 4th gear.TCM
 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
 Torque converter turbine speed sensor
 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
 Torque converter turbine speed sensor
 Accelerator pedal position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
2-4 brake
 ATF deterioration
 Engine performance
 Low & reverse duty solenoid Symptom Problem parts

4AT(H4DOTC)-129
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Slippage occurs from 1st to 2nd gear.TCM
 Accelerator pedal position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
2-4 brake
Shock occurs from 2nd to 3rd gear.TCM
 Torque converter turbine speed sensor
 Accelerator pedal position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure linear solenoid
 Low & reverse duty solenoid
 Control valve
High clutch
2-4 brake
 ATF deterioration
 Engine performance
 High clutch duty solenoid
Slippage occurs from 2nd to 3rd gear.TCM
 Accelerator pedal position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
High clutch
2-4 brake
 Low & reverse duty solenoid
Shock occurs from 3rd to 4th gear.TCM
 Torque converter turbine speed sensor
 Accelerator pedal position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
 Low clutch duty solenoid
2-4 brake
 ATF deterioration
 Engine performance
Slippage occurs from 3rd to 4th gear.TCM
 Accelerator pedal position sensor
 2-4 brake duty solenoid
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
2-4 brake
Shock occurs when select lever is shifted from “3” to “2” range.TCM
 Torque converter turbine speed sensor
 Accelerator pedal position sensor
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
 2-4 brake duty solenoid
2-4 brake
 ATF deterioration
 High clutch duty solenoid Symptom Problem parts

4AT(H4DOTC)-130
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Shock occurs when select lever is shifted from “D” to “1” range.TCM
 Torque converter turbine speed sensor
 Accelerator pedal position sensor
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
 ATF deterioration
 Low & reverse brake duty solenoid
 Low & reverse clutch solenoid
Shock occurs when select lever is shifted from “2” to “1” range.TCM
 Torque converter turbine speed sensor
 Accelerator pedal position sensor
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
 Low & reverse clutch
 ATF deterioration
 2-4 brake duty solenoid
 Low & reverse brake duty solenoid
Shock occurs when accelerator pedal is released at medium
speeds.TCM
 Accelerator pedal position sensor
 ATF temperature sensor
 Line pressure linear solenoid
 Control valve
 Lock-up damper
 Engine performance
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” phenome-
non).TCM
 Front vehicle speed sensor
 Rear vehicle speed sensor
 Accelerator pedal 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
 Accelerator pedal position sensor
 ATF temperature sensor
 Control valve
 Transfer clutch
Transfer valve
 Transfer pipe
 Transfer duty solenoid
Vehicle is not set in FWD mode.TCM
 Transfer clutch
Transfer valve
 Transfer duty solenoid
Select lever is hard to move. Select cable
 Select lever
 Detente spring
 Manual plate Symptom Problem parts

4AT(H4DOTC)-131
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Select lever is too high to move (unreasonable resistance). Detente spring
 Manual plate
Select lever slips out of operation during acceleration or while
driving on rough terrain. Select cable
 Select lever
 Detente spring
 Manual plate Symptom Problem parts

4AT(H4DOTC)-132
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic