Subaru Legacy 2003 Service Manual page 2072

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK ANY OTHER DTC ON DISPLAY.
Is any other DTC displayed?
2 CHECK AIR INTAKE SYSTEM.
1) Turn the ignition switch to ON.
2) Start the engine, and idle it.
3) Check the following items:
•Loose installation of intake manifold, idle air
control solenoid valve and throttle body
•Cracks of intake manifold gasket, idle air con-
trol solenoid valve gasket and throttle body
gasket
•Disconnections of vacuum hoses
Is there a fault in the air intake system?
3 CHECK THROTTLE CABLE.
Does the throttle cable have play for adjust-
ment?
4 CHECK AIR BY-PASS LINE.
1) Turn the ignition switch to OFF.
2) Remove the idle air control solenoid valve
from throttle body. <Ref. to
FU(H4DOSTC)-35, Idle Air Control Sole-
noid Valve.>
3) Confirm that there are no foreign particles
in the by-pass air line.
Are foreign particles in the by-pass air line?
Value
DTC indicated.
There is no problem.
Cable has play correctly.
Foreign particles are in the by-
pass air line.
EN(H4DOSTC)-233
ENGINE (DIAGNOSTICS)
Yes
Inspect the rele- Go to step 2.
vant DTC using
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(H4DOSTC)-
62, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0507.
Go to step 3. Repair the air suc-
tion and leaks.
Go to step 4. Adjust the throttle
cable. <Ref. to
SP(H4SO)-10,
Accelerator Con-
trol Cable.>
Remove the for- Replace the idle
eign particles from air control solenoid
by-pass air line. valve. <Ref. to
FU(H4DOSTC)-
35, Idle Air Con-
trol Solenoid
Valve.>
No