Subaru FORESTER 2001 Service Manual page 148

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK ANY OTHER DTC ON DISPLAY.
2 CHECK ENGINE COOLING SYSTEM.
NOTE:
Check the following items.
¼ Thermostat open stuck
¼ Coolant level
¼ Coolant freeze
¼ Tire diameter
Step
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC
P0117 or P0118?
Is there a fault in engine
cooling system?
EN(DOHC TURBO)-147
Check Yes
Inspect DTC
P0117 or P0118
using "List of
Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(DOHC
TURBO)-82, List
of Diagnostic
Trouble Code
(DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0125.
Replace thermo-
stat. <Ref. to
CO-23, Thermo-
stat.>
Engine (Diagnostics)
No
Go to step 2.
Replace engine
coolant tempera-
ture sensor. <Ref.
to FU(DOHC
TURBO)-29,
Engine Coolant
Temperature Sen-
sor.>