Subaru Legacy III (2000-2003 year). Manual - part 607

AT-162

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

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

AT-163

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

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

AT-164

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

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

Vibration occurs during turns (tight corner “braking” phenome-
non).

• 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
• Detent spring
• Manual plate

Select lever is too high to move (unreasonable resistance).

• Detent spring
• Manual plate

Symptom

Problem parts

AT-165

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

SYMPTOM RELATED DIAGNOSTIC

Select lever slips out of operation during acceleration or while 
driving on rough terrain.

• Select cable
• Select lever
• Detent spring
• Manual plate

System does not shift to SPORT shift mode.

SPORT shift mode switch

Engine brake is not effected in SPORT shift mode with 1st gear.

• SPORT shift solenoid
• Control valve
• Low and reverse clutch

Symptom

Problem parts