Subaru Legacy IV (2008 year). Manual - part 775

5AT(diag)-115

General Diagnostic Table

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

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

• Fluid level and condition
• Vehicle speed sensor 1 and vehicle speed sensor 2
• Forward 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
• Forward 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

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 

o 2nd of “D” range or “1st 

of manual mode” 

o “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 

o 3rd of “D” range or “2nd 

of manual mode” 

o “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 

o 4th of “D” range or “3rd 

of manual mode” 

o “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)-116

General Diagnostic Table

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Gear does not shift 4th of “D” range 

o 5th of “D” range or “4th 

of manual mode” 

o “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
• Turbine speed sensor 1 and turbine speed sensor 2
• 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

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
• Turbine speed sensor 1 and turbine speed sensor 2
• Lock up solenoid valve
• CAN communication signal
• ATF temperature sensor
• Accelerator pedal position sensor
• Brake switch signal
• Range signal

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

o 2nd of 

“D” range or “1st of manual mode” 

o “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)-117

General Diagnostic Table

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

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

o 3rd of 

“D” range or “2nd of manual mode” 

o 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 

o 4th of 

“D” range or “3rd of manual mode” 

o “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 

o 5th of 

“D” range or “4th of manual mode” 

o “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 

o 4th of “D” range 

or “5th of manual mode” 

o “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 

o 3rd of “D” range 

or “4th of manual mode” 

o “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 

o 2nd of “D” range 

or “3rd of manual mode” 

o “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 

o 1st of “D” range 

or “2nd of manual mode” 

o “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 

o 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 

o 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)-118

General Diagnostic Table

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Engine brake does not function at 3rd 

o 2nd of manual mode.

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

Engine brake does not function at 2nd 

o 1st of manual mode.

• Inhibitor switch
• Fluid level and condition
• Control cable adjustment
• Manual mode switch
• Oil pressure switch 4
• Forward 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 in “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