Page 2570 of 2870

4AT(H4SO)-111
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Symptom Related Diagnostic
Vehicle does not start in any shift range (engine revving up). Strainer
Line pressure duty 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 transmission case
Vehicle does not start in “R” range only (engine revving up). Select cable
Select lever
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
Front gasket 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
No shift occurs from 1st to 2nd gear.TCM
Rear vehicle speed sensor
Front vehicle speed sensor
Throttle position sensor
Shift solenoid 1
Control valve
2-4 brake
No shift occurs from 2nd to 3rd gear.TCM
Control valve
High clutch
Shift solenoid 2 Symptom Problem parts
Page 2571 of 2870

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
Page 2572 of 2870

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
Page 2573 of 2870

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
Page 2581 of 2870

4AT(H4DOTC)-5
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
3. General Description
A: CAUTION
Supplemental Restraint System “Airbag”
The airbag system wiring harness is routed near
the TCM.
CAUTION:
All airbag system wiring harness and con-
nectors are colored yellow. Do not use an elec-
trical test equipment on these circuit.
Be careful not to damage the airbag system
wiring harness when performing diagnostics and
servicing the TCM.
Measurement
When measuring the voltage and resistance of
ECM, TCM or each sensor, use a tapered pin with
diameter of less than 0.64 mm (0.025 in) in order to
avoid poor contact. Do not insert the pin more than
0.65 mm (0.026 in).
B: INSPECTION
1. BATTERY
Measure the battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V or more
Specific gravity: Above 1.260
2. TRANSMISSION GROUND
Make sure that the ground terminal bolt is tightened
securely.
Chassis side
Tightening torque:
13 N
⋅m (1.3 kgf-m, 9.4 ft-lb)
3. ATF LEVEL
Make sure that ATF level is in the specification.
to 4AT-30, INSPECTION, Automatic Transmission
Fluid.>
4. FRONT DIFFERENTIAL OIL LEVEL
Make sure that front differential oil level is in the spec-
ification.
Gear Oil.>
AT-00412
(A) Level gauge
(B) “HOT” side
(C) Upper level
(D) Lower level
(E) “COLD” side
(A) Upper level
(B) Lower level
PI-00105
COLD
LFHOT LF
(A)
(C)
(D)
(C)
(D)
(E)
(B)
AT-00317
(A)
(B)
LF
Page 2583 of 2870
4AT(H4DOTC)-7
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
C: PREPARATION TOOL
1. SPECIAL TOOL
2. GENERAL TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
24082AA230
(Newly adopted tool)CARTRIDGE Troubleshooting for electrical system.
22771AA030 SUBARU SELECT
MONITOR KITTroubleshooting for electrical system.
English: 22771AA030 (Without printer)
German: 22771AA070 (Without printer)
French: 22771AA080 (Without printer)
Spanish: 22771AA090 (Without printer)
TOOL NAME REMARKS
Circuit tester Used for measuring resistance, voltage and current.
Oscilloscope Used for measuring sensor.
ST24082AA230
ST22771AA030
Page 2586 of 2870
4AT(H4DOTC)-10
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Electrical Components Location
2. SENSOR
(1) Throttle position sensor (2.0 L
model)(4) Rear vehicle speed sensor (7) Accelerator pedal position sensor
(2.5 L model)
(5) Torque converter turbine speed
sensor (2) Front vehicle speed sensor
(3) Inhibitor switch (6) ATF temperature sensor
AT-01836
(3) (6)
(5) (1) (2) (4)(7)
(1)
AT-01105
AT-01474
(2)(4)
(3)AT-00330
(5)
AT-00331
Page 2589 of 2870

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)