Subaru Legacy (2005 year). Manual - part 637

5AT(diag)-139

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

General Diagnostic Table

Hold at “D” range or 2nd on manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Low coast brake solenoid valve
• Line pressure
• Up switch signal
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor

Hold at “D” range or 3rd on manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Line pressure
• Up switch signal
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor

Hold at “D” range or 4th on manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 3 and Input clutch solenoid valve
• Oil pressure switch 4 and Direct clutch solenoid valve
• Oil pressure switch 5 and High & low reverse clutch solenoid 
valve
• Low coast brake solenoid valve
• Front brake solenoid valve
• Line pressure
• Up switch signal
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor
• TCM power supply
• PVIGN relay

Hold at “D” range or 5th on manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 1 and Front brake solenoid valve
• Line pressure
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor

Gear does not shift 1st of “D” range 

→ 2nd of “D” range or “1st 

of manual mode” 

→ “2nd of manual mode”.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Up switch
• CAN communication signal
• Accelerator pedal position sensor

Gear does not shift 2nd of “D” range 

→ 3rd of “D” range or “2nd 

of manual mode” 

→ “3rd of manual mode”.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 5 and High & low reverse clutch solenoid 
valve
• Line pressure
• Up switch signal
• CAN communication signal
• Accelerator pedal position sensor

Gear does not shift 3rd of “D” range 

→ 4th of “D” range or “3rd 

of manual mode” 

→ “4th of manual mode”.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 3 and Input clutch solenoid valve
• Oil pressure switch 1 and Front brake solenoid valve
• Line pressure
• Up switch signal
• CAN communication signal
• Accelerator pedal position sensor

Symptom

Problem parts

5AT(diag)-140

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

General Diagnostic Table

Gear does not shift 4th of “D” range 

→ 5th of “D” range or “4th 

of manual mode” 

→ “5th of manual mode”.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 1 and Front brake solenoid valve
• Oil pressure switch 4 and Direct clutch solenoid valve
• Torque converter turbine speed sensor
• ATF temperature sensor
• Line pressure
• Up switch signal
• CAN communication signal
• Accelerator pedal position sensor

Gear does not shift down to 4th on “D” range or manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 1 and Front brake solenoid valve
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor

Gear does not shift down to 3rd on “D” range or manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 3 and Input clutch solenoid valve
• Oil pressure switch 1 and Front brake solenoid valve
• Line pressure
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor
• TCM power supply
• PVIGN relay

Gear does not shift down to 2nd on “D” range or manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 5 and High & low reverse clutch solenoid
• Line pressure
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor

Gear does not shift down to 1st on “D” range or manual mode.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Down switch signal
• CAN communication signal
• Accelerator pedal position sensor

No lock-up occurs.

• Fluid level and condition
• Line pressure
• Engine speed signal
• Torque converter turbine speed sensor
• Lock up solenoid valve
• CAN communication signal
• ATF temperature sensor 1 and 2
• Accelerator pedal position sensor
• Brake switch signal
• Range signal

No shift shock occurred when shifting 1st of “D” range 

→ 2nd of 

“D” range or “1st of manual mode” 

→ “2nd of manual mode”. Or 

clutch slipping occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• CAN communication signal

Symptom

Problem parts

5AT(diag)-141

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

General Diagnostic Table

No shift shock occurred when shifting 2nd of “D” range 

→ 3rd of 

“D” range or “2nd of manual mode” 

→ “3rd of manual mode”. Or 

clutch slipping occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 5 and High & low reverse clutch solenoid 
valve
• Line pressure
• CAN communication signal

No shift shock occurred when shifting 3rd of “D” range 

→ 4th of 

“D” range or “3rd of manual mode” 

→ “4th of manual mode”. Or 

clutch slipping occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 3 and Input clutch solenoid valve
• Oil pressure switch 1 and Front brake solenoid valve
• Line pressure
• CAN communication signal

No shift shock occurred when shifting 4th of “D” range 

→ 5th of 

“D” range or “4th of manual mode” 

→ “5th of manual mode”. Or 

clutch slipping occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 1 and Front brake solenoid valve
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor

Engine skids when shifting 5th of “D” range 

→ 4th of “D” range 

or “5th of manual mode” 

→ “4th of manual mode”. Or slipping 

occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 1 and Front brake solenoid valve
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor

Engine skids when shifting 4th of “D” range 

→ 3rd of “D” range 

or “4th of manual mode” 

→ “3rd of manual mode”. Or slipping 

occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 3 and Input clutch solenoid valve
• Oil pressure switch 1 and Front brake solenoid valve
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor

Engine skids when shifting 3rd of “D” range 

→ 2nd of “D” range 

or “3rd of manual mode” 

→ “2nd of manual mode”. Or slipping 

occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 5 and High & low reverse clutch solenoid 
valve
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor

Engine skids when shifting 2nd of “D” range 

→ 1st of “D” range 

or “2nd of manual mode” 

→ “1st of manual mode”. Or slipping 

occurred.

• Fluid level and condition
• Vehicle speed sensor 1 and Vehicle speed sensor 2
• Oil pressure switch 4 and Direct clutch solenoid valve
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor

Engine brake does not function at 5th 

→ 4th of manual mode.

• Inhibitor switch
• Fluid level and condition
• Control cable adjustment
• Manual mode switch
• Oil pressure switch 1
• Down switch signal

Engine brake does not function at 4th 

→ 3rd of manual mode.

• Inhibitor switch
• Fluid level and condition
• Control cable adjustment
• Manual mode switch
• Oil pressure switch 1 and Oil pressure switch 3
• Down switch signal

Symptom

Problem parts

5AT(diag)-142

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

General Diagnostic Table

Engine brake does not function at 3rd 

→ 2nd of manual mode.

• Inhibitor switch
• Fluid level and condition
• Control cable adjustment
• Manual mode switch
• Oil pressure switch 5
• Low coast brake solenoid valve

Engine brake does not function at 2nd 

→ 1st of manual mode.

• Inhibitor switch
• Fluid level and condition
• Control cable adjustment
• Manual mode switch
• Oil pressure switch 4
• Low coast brake solenoid valve

Excessive acceleration failure on “D” range.

• Fluid level and condition
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor
• CAN communication signal
• Inhibitor switch
• Control cable adjustment
• Vehicle speed sensor 1, 2

Excessive acceleration failure on “R” range.

• Fluid level and condition
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor
• Oil pressure switch 5 and High & low reverse clutch solenoid 
valve
• CAN communication signal
• Inhibitor switch
• Control cable adjustment
• Vehicle speed sensor 1, 2

Engine skids when start driving (1st) the vehicle. Or slipping 
occurred.

• Fluid level and condition
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor
• CAN communication signal

Engine skids when driving at 2nd. Or slipping occurred.

• Fluid level and condition
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor
• CAN communication signal
• Oil pressure switch 4 and Direct clutch solenoid valve

Engine skids when driving at 3rd. Or slipping occurred.

• Fluid level and condition
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor
• CAN communication signal
• Oil pressure switch 5 and High & low reverse clutch solenoid 
valve

Engine skids when driving at 4th. Or slipping occurred.

• Fluid level and condition
• Line pressure
• Accelerator pedal position sensor
• Throttle position sensor
• CAN communication signal
• Oil pressure switch 3 and Input clutch solenoid valve

Symptom

Problem parts