Subaru 2009 IMPREZA Service Manual page 2031

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Step
8 CHECK HARNESS CONNECTOR BETWEEN
BODY INTEGRATED UNIT AND STOP LIGHT
SWITCH.
Measure the resistance of harness between
body integrated unit and stop light switch.
Connector & terminal
(B280) No. 2 — Chassis ground:
9 CHECK POOR CONTACT.
Check
Is the resistance 1 M or
more?
Is there poor contact of input
signal of brake switch?
4AT(diag)-46
Yes No
Go to step 9. Repair the short
circuit of harness
between body inte-
grated unit and
stop light switch.
Repair the poor Check body inte-
contact. grated unit.