Subaru Legacy 2004 Service Manual page 909

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
13 CHECK FUEL LEVEL.
14 CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1) Clear the memory using Subaru Select
Monitor. <Ref. to EN(H4SO 2.5)(diag)-41,
Clear Memory Mode.>
2) Start the engine, and drive the vehicle more
than 10 minutes.
15 CHECK CAUSE OF MISFIRE DIAGNOSED.
16 CHECK AIR INTAKE SYSTEM.
17 CHECK CYLINDER.
Check
Is the fuel meter indication
higher than the "Lower" level?
Does the malfunction indicator
light come on or blink?
Was the cause of misfire diag-
nosed when the engine is run-
ning?
Is there any fault in air intake
system?
Is there any fault in that cylin-
der?
EN(H4SO 2.5)(diag)-150
Yes
Go to step 14. Replenish the fuel
so fuel meter indi-
cation is higher
than the "Lower"
level. After replen-
ishing fuel, go to
step 14.
Go to step 16. Go to step 15.
Finish the diag- Repair the poor
nostics operation, contact.
if the engine has
NOTE:
no abnormality.
In this case, repair
the following:
• Poor contact in
ignition coil con-
nector
• Poor contact in
fuel injector con-
nector on faulty
cylinders
• Poor contact in
ECM connector
• Poor contact in
coupling connector
Repair the air Go to step 17.
intake system.
NOTE:
Check the follow-
ing items:
• Are there air
leaks or air suction
caused by loose or
dislocated nuts
and bolts?
• Are there cracks
or any disconnec-
tion of hoses?
Repair or replace Go to DTC P0171
the faulty parts. and P0172. <Ref.
to EN(H4SO
NOTE:
2.5)(diag)-136,
Check the follow-
DTC P0171 SYS-
ing items.
TEM TOO LEAN
• Spark plug
(BANK 1), Diag-
• Fuel injector
nostic Procedure
• Compression
with Diagnostic
pressure
Trouble Code
(DTC).>
No