Subaru 2002 IMPREZA Service Manual page 596

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
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
22 GROUP OF #1 AND #2 CYLINDERS
Check
Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0303 and
P0304?
Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0301 and
P0303?
Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0302 and
P0304?
Is there a fault in that cylinder? Repair or replace
Are there faults in #1 and #2
cylinders?
EN-164
Yes
Go to step 23. Go to step 19.
Go to step 24. Go to step 20.
Go to step 25. Go to step 26.
Go to DTC P0170.
the faulty parts. <Ref. to EN-156,
DTC P0170 —
NOTE:
FUEL TRIM MAL-
Check the follow-
FUNCTION —,
ing items.
Diagnostic Proce-
• Spark plug
dure with Diagnos-
• Spark plug cord
tic Trouble Code
• Fuel injector
(DTC).>
• Compression
ratio
Repair or replace Go to DTC P0170.
the faulty parts. <Ref. to EN-156,
DTC P0170 —
NOTE:
FUEL TRIM MAL-
• Check the fol-
FUNCTION —,
lowing items.
Diagnostic Proce-
• Spark plugs
dure with Diagnos-
• Fuel injectors
tic Trouble Code
• Ignition coil
(DTC).>
• Compres-
sion ratio
• If no abnormal is
discovered, check
for "IGNITION
CONTROL SYS-
TEM" of #1 and #2
cylinders side.
<Ref. to EN-72,
IGNITION CON-
TROL SYSTEM,
Diagnostics for
Engine Starting
Failure.>
No