Subaru FORESTER 2001 Service Manual page 179

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
15 CHECK AIR INTAKE SYSTEM.
16 CHECK MISFIRE SYMPTOM.
1) Turn ignition switch to ON.
2) Read diagnostic trouble code (DTC).
¼ Subaru Select Monitor
<Ref. to EN(DOHC TURBO)-36, Subaru
Select Monitor.>
¼ OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
NOTE:
Perform diagnosis according to the items
listed below.
17 CHECK DIAGNOSTIC TROUBLE CODE
(DTC) ON DISPLAY.
18 CHECK DIAGNOSTIC TROUBLE CODE
(DTC) ON DISPLAY.
19 CHECK DIAGNOSTIC TROUBLE CODE
(DTC) ON DISPLAY.
20 CHECK DIAGNOSTIC TROUBLE CODE
(DTC) ON DISPLAY.
21 ONLY ONE CYLINDER
Step
Is there a fault in air intake
system?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate only one
DTC?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC
P0301 and P0302?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC
P0303 and P0304?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC
P0301 and P0303?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC
P0302 and P0304?
Is there a fault in that cylin-
der?
EN(DOHC TURBO)-178
Check Yes
Repair air intake
system.
NOTE:
Check the follow-
ing items:
¼ Are there air
leaks or air suc-
tion caused by
loose or dislo-
cated nuts and
bolts?
¼ Are there
cracks or any dis-
connection of
hoses?
Go to step 21.
Go to step 22.
Go to step 23.
Go to step 24.
Go to step 25.
Repair or replace
faulty parts.
NOTE:
Check the follow-
ing items.
¼ Spark plug
¼ Fuel injector
¼ Compression
ratio
No
Go to step 16.
Go to step 17.
Go to step 18.
Go to step 19.
Go to step 20.
Go to step 26.
Go to DTC P0171
and P0172. <Ref.
to EN(DOHC
TURBO)-160,
DTC P0171 -
FUEL TRIM MAL-
FUNCTION (A/F
TOO LEAN) -,
Diagnostic Proce-
dure with Diag-
nostic Trouble
Code (DTC).>