Subaru 2009 IMPREZA Service Manual page 1988

Step
6 PERFORM DIAGNOSIS.
1) Inspect using "Diagnostic Procedure with
Diagnostic Trouble Code (DTC)". <Ref. to
4AT(diag)-31, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>
NOTE:
Refer to "List of Diagnostic Trouble Code
(DTC)" for DTC. <Ref. to 4AT(diag)-29, List of
Diagnostic Trouble Code (DTC).>
2) Repair the trouble cause.
3) Perform the Clear Memory Mode.
4) Perform the Inspection Mode. <Ref. to
4AT(diag)-20, Inspection Mode.>
5) Read the DTC.
Basic Diagnostic Procedure
Is DTC displayed on the Subaru
Select Monitor?
4AT(diag)-3
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Check Yes
Inspect using
"Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC)". <Ref. to
4AT(diag)-31,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>
No
Finish the diagno-
sis.