Basic Diagnostic Procedure - Subaru Legacy 2002 Service Manual

Engine (Diagnostics)

1. Basic Diagnostic Procedure

S078501
A: PROCEDURE
1. ENGINE
S078501E4501
No.
1 CHECK ENGINE START FAILURE.
1) Ask the customer when and how the
trouble occurred using the interview check list.
<Ref. to EN-4, CHECK, Check List for Inter-
view.>
2) Start the engine.
2 CHECK ILLUMINATION OF CHECK ENGINE
MALFUNCTION INDICATOR LAMP (MIL).
3 CHECK INDICATION OF DTC ON DISPLAY.
1) Turn ignition switch to OFF.
2) Connect the Subaru Select Monitor or the
OBD-II general scan tool to data link connec-
tor.
3) Turn ignition switch to ON and the Subaru
Select Monitor or OBD-II general scan tool
switch to ON.
4) Read DTC on the Subaru Select Monitor or
OBD-II general scan tool.
4 PERFORM THE DIAGNOSIS.
1) Perform the clear memory mode. <Ref. to
EN-45, Clear Memory Mode.>
2) Perform the inspection mode. <Ref. to
EN-42, Inspection Mode.>
BASIC DIAGNOSTIC PROCEDURE
S078501E45
Step Check
Does the engine start?
Does CHECK ENGINE
malfunction indicator lamp
illuminate?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC?
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC?
EN-2
Yes
Go to step 2. Inspection using
"Diagnostics for
Engine Start Fail-
ure". <Ref. to
EN-61, Diagnos-
tics for Engine
Starting Failure.>
Go to step 3. Inspection using
"General Diagnos-
tics Table". <Ref.
to EN-292,
INSPECTION,
General Diagnos-
tic Table.>
Record DTC. Repair the related
Repair the trouble parts.
cause. <Ref. to NOTE:
EN-82, List of If DTC is not
Diagnostic shown on display
Trouble Code although the MIL
(DTC).> Go to illuminates, per-
step 4. form diagnostics
of MIL (CHECK
ENGINE malfunc-
tion indicator
lamp) circuit or
combination
meter. <Ref. to
EN-48, Engine
Malfunction Indi-
cator Lamp
(MIL).>
Inspect using Complete the
"Diagnostics Pro- diagnosis.
cedure with Diag-
nostic Trouble
Code (DTC)".
<Ref. to EN-88,
Diagnostic Proce-
dure with Diag-
nostic Trouble
Code (DTC).>
No