Subaru Legacy 2002 Service Manual page 1214

¼ The antenna feeder must be placed as far
apart as possible from the ECM and MFI har-
ness.
¼ Carefully adjust the antenna for correct
matching.
¼ When mounting a large power type radio,
pay special attention to the three items above
mentioned.
¼ Incorrect installation of the radio may affect
the operation of the ECM.
13) Before disconnecting the fuel hose, discon-
nect the fuel pump connector and crank the engine
for more than five seconds to release pressure in
the fuel system. If engine starts during this
operation, run it until it stops.
14) Problems in the electronic-controlled auto-
matic transmission may be caused by failure of the
engine, the electronic control system, the transmis-
sion proper, or by a combination of these. These
three causes must be distinguished clearly when
performing diagnostics.
15) Diagnostics should be conducted by rotating
with simple, easy operations and proceeding to
complicated, difficult operations. The most impor-
tant thing in diagnostics is to understand the cus-
tomer's complaint, and distinguish between the
three causes.
16) In AT vehicles, do not continue the stall for
more than five seconds at a time (from closed
throttle, fully open throttle to stall engine speed).
17) On ABS vehicle, when performing driving test
in jacked-up or lifted-up position, sometimes the
warning light may be lit, but this is not a malfunc-
tion of the system. The reason for this is the speed
difference between the front and rear wheels. After
diagnosis of engine control system, perform the
ABS memory clearance procedure of self-diagno-
sis system.
B: INSPECTION
Before performing diagnostics, check the following
items which might affect engine problems:
1. BATTERY
S048001A1001
1) Measure battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V
Specific gravity: Above 1.260
2) Check the condition of the main and other
fuses, and harnesses and connectors. Also check
for proper grounding.
GENERAL DESCRIPTION
S048001A10
2. ENGINE GROUNDING
Make sure the engine grounding terminal is prop-
erly connected to the engine.
C: NOTE
1. DESCRIPTION
¼ The on-board diagnostics (OBD) system detects
and indicates a fault in various inputs and outputs
of the complex electronic control. CHECK ENGINE
malfunction indicator lamp (MIL) in the combina-
tion meter indicates occurrence of a fault or
trouble.
¼ Further, against such a failure or sensors as
may disable the drive, the fail-safe function is pro-
vided to ensure the minimal driveability.
¼ The OBD system incorporated with the vehicles
within this engine family complies with Section
1968.1, California Code of Regulations (OBD-II
regulation). The OBD system monitors the compo-
nents and the system malfunction listed in Engine
Section which affects on emissions.
¼ When the system decides that a malfunction
occurs, MIL illuminates. At the same time of the
MIL illumination or blinking, a diagnostic trouble
code (DTC) and a freeze frame engine conditions
are stored into on-board computer.
¼ The OBD system stores freeze frame engine
condition data (engine load, engine coolant
temperature, fuel trim, engine speed and vehicle
speed, etc.) into on-board computer when it
detects a malfunction first.
¼ If the OBD system detects the various malfunc-
tions including the fault of fuel trim or misfire, the
OBD system first stores freeze frame engine con-
ditions about the fuel trim or misfire.
¼ When the malfunction does not occur again for
three consecutive driving cycles, MIL is turned off,
but DTC remains at on-board computer.
¼ The OBD-II system is capable of communication
with a general scan tool (OBD-II general scan tool)
formed by ISO 9141 CARB.
¼ The OBD-II diagnostics procedure is different
from the usual diagnostics procedure. When
troubleshooting OBD-II vehicles, connect Subaru
EN(H6)-7
Engine (DIAGNOSTICS)
S048001A1002
S048001A15
S048001A1501
B2M4376