Subaru 2002 IMPREZA Service Manual page 403

a
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Check
4re there faults in #1 and #2
:ylinders?
Ire there faults in #3 and #4
:ylinders?
4re there faults in #1 and #3
:ylinders?
Step
GROUP OF #1 AND #2 CYLINDERS
!2
Yes
Repair or replace
faulty parts.
NOTE:
Check the fol-
lowing items.
Spark plugs
Fuel injectors
Ignition coil
Compres-
sion ratio
If no abnormal is
discovered, check
for "IGNITION
TEM" of #1 and #2
cylinders side.
<Ref. to EN(D0HC
TION CONTROL
SYSTEM, Diag-
nostics for Engine
Starting Failure.>
Repair or replace
faulty parts.
NOTE:
Check the fol-
lowing items.
CONTROL SYS-
TURBO)-72, IGNI-
Spark plugs
Fuel injectors
Ignition coil
If no abnormal is
discovered, check
for "IGNITION
TEM" of #3 and #4
cylinders side.
<Ref. to EN(D0HC
TION CONTROL
SYSTEM, Diag-
nostics for Engine
Starting Failure.>
Repair or replace
faulty parts.
NOTE:
Check the follow-
ing items.
Spark plugs
Fuel injectors
Skipping timing
belt teeth
CONTROL SYS-
TURBO)-72, IGNI-
2 3
GROUP OF
#3
AND #4 CYLINDERS
24
GROUP OF #1 AND
#3 CYLINDERS
No
Go to DTC PO171
and P0172. <Ref.
to EN(D0HC
TURBO)-1 52,
DTC PO171
-
FUEL TRIM MAL-
FUNCTION ( N F
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>
TOO LEAN) -,
Go to DTC PO171
and P0172. <Ref.
to EN(D0HC
TURBO)-1 52,
DTC PO171
-
FUEL TRIM MAL-
FUNCTION (NF
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>
TOO LEAN)
-,
Go to DTC PO171
and PO172. <Ref.
to EN(D0HC
TURBO)-1 52,
DTC PO171
-
FUEL TRIM MAL-
FUNCTION ( N F
Diagnostic Proce-
dure with Diagnos
tic Trouble Code
( D T C b
TOO LEAN) -,
EN(D0HC TURBO)-I79