Subaru 2009 IMPREZA Service Manual page 600

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
13 CHECK CAUSE OF MISFIRE.
14 CHECK AIR INTAKE SYSTEM.
15 CHECK MISFIRE SYMPTOM.
1) Turn the ignition switch to ON.
2) Read the DTC.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
16 CHECK DTC.
17 CHECK DTC.
18 CHECK DTC.
19 CHECK DTC.
Check
Was the cause of misfire identi-
fied when the engine is run-
ning?
Is there any fault in air intake
system?
Does the Subaru Select Moni-
tor or general scan tool indicate
only one DTC?
Are DTC P0301 and P0302 dis-
played on the Subaru Select
Monitor or general scan tool?
Are DTC P0303 and P0304 dis-
played on the Subaru Select
Monitor or general scan tool?
Are DTC P0301 and P0303 dis-
played on the Subaru Select
Monitor or general scan tool?
Are DTC P0302 and P0304 dis-
played on the Subaru Select
Monitor or general scan tool?
EN(H4SO)(diag)-183
ENGINE (DIAGNOSTICS)
Yes No
Finish diagnostics Repair the poor
operation, if the contact of connec-
engine has no tor.
abnormality.
NOTE:
In this case, repair
the following item:
• Poor contact of
ignition coil con-
nector
• Poor contact of
fuel injector con-
nector on
cylinders
• Poor contact of
ECM connector
• Poor contact of
coupling connector
Repair the air Go to step 15.
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?
Go to step 20. Go to step 16.
Go to step 21. Go to step 17.
Go to step 22. Go to step 18.
Go to step 23. Go to step 19.
Go to step 24. Go to step 25.
faulty