2003 TOYOTA COROLLA Diagnostic

’03 Corolla U (L/O 0201)
402003 MY COROLLA_U (OM12744U)
The SRS (Supplemental Restraint Sys-
tem) front airbags are designed to pro-
vide further protection for the driver
and front passenger in addition to the
primary safety protection provided by
the seat belts.
In response to a severe frontal impact,
the SRS front airbags work together with
the seat belts to help reduce injury by
inflating. The SRS front airbags help to
reduce injuries mainly to the driver ’s or
front passenger ’s head or chest caused by
directly hitting the steering wheel or dash-
board. The front passenger airbag is acti-
vated even with no passenger in the front
seat.
Be sure to wear your seat belt properly.Your vehicle is equipped with a crash
sensing and diagnostic module, which will
record the use of the seat belt restraint
system by the driver and front pass
enger
when the SRS airbags are inflated.
CAUTION
The driver or front passenger who is
too close to the steering wheel or
dashboard during airbag deployment
can be killed or seriously injured.
Toyota strongly recommends that:
The driver sit as far back as pos-
sible from the steering wheel while
still maintaining control of the ve-
hicle.
The front passenger sit as far back
as possible from the dashboard.
All vehicle occupants be properly
restrained using the available seat
belts.
This indicator comes on when the igni-
tion key is turned to the “ON” position.
It goes off after about 6 seconds. This
means the SRS front airbags are oper-
ating properly.
This warning light system monitors the
airbag sensor assembly, front airbag sen-
sors, side airbag sensors, driver ’s seat
position sensor, driver ’s seat belt buckle
switch, front seat belt pretensioner assem-
blies, inflators, warning light, interconnect-
ing wiring and power sources. (For details,
see “Service reminder indicators and
warning buzzers” on page 85 in Section
15.)
SRS driver airbag and front
passenger airbag

’03 Corolla U (L/O 0201)
482003 MY COROLLA_U (OM12744U)
Your vehicle is equipped with a crash
sensing and diagnostic module, which will
record the use of the seat belt restraint
system by the driver and front passenger
when the SRS side airbags are inflated.
CAUTION
SRS side airbags inflate with consid-
erable force. To avoid potential death
or serious injury when they inflate,
the driver and front passenger must:
Wear their seat belts properly.
Remain properly seated with their
back upright and against the seat at
all times.This indicator comes on when the igni-
tion key is turned to the “ON” position.
It goes off after about 6 seconds. This
means the SRS side airbags are operat-
ing properly.
This warning light system monitors the
airbag sensor assembly, front airbag sen-
sors, side airbag sensors, driver ’s seat
position sensor, driver ’s seat belt buckle
switch, front seat belt pretensioner assem-
blies, inflators, warning light, interconnect-
ing wiring and power sources. (For details,
see “Service reminder indicators and
warning buzzers” on page 85 in Section
15.)The SRS side airbag system may not
activate if the vehicle is subjected to a
collision from the side at certain
angles, or a collision to the side of the
vehicle body other than the passenger
compartment as shown in the illustra-
tion.
The SRS side airbags are designed to
inflate when the passenger compartment
area suffers a severe impact from the
side.
For the safety of all occupants, always
wear your seat belts properly.

’03 Corolla U (L/O 0201)
872003 MY COROLLA_U (OM12744U)
(b) Driver’s Seat Belt Reminder Lightand Buzzer
This light and buzzer remind you to
buckle up the driver’s seat belt.
Once the ignition key is turned to “ON” or
“START”, the reminder light flashes and
buzzer sounds if the driver ’s seat belt is
not fastened. Unless the driver fastens the
belt, the light keeps flashing and the
buzzer stops after about 4 to 8 seconds.
(c) Front Passenger ’s Seat Belt Reminder Light
This light reminds you to buckle up the
front passenger ’s seat belt.
Once the ignition key is turned to “ON” or
“START”, the reminder light flashes if a
passenger sits in the front passenger seat
and does not fasten the seat belt. Howev-
er, if a front passenger uses an additional
seat cushion, the light may not flash even
when the seat belt is not buckled up.
If luggage load is placed on the front
passenger seat, depending on its weight
and how it is placed on the seat, builtin
sensors in the seat cushion may detect
the pressure, causing the reminder light to
keep flashing. (d) Discharge Warning Light
This light warns that the battery is being
discharged.
If it comes on while you are driving, there
is a problem somewhere in the charging
system.
The engine ignition will continue to oper-
ate, however, until the battery is dis-
charged. Turn off the air conditioning,
blower, radio, etc., and drive directly to
the nearest Toyota dealer or repair shop.
NOTICE
Do not continue driving if the engine
drive belt is broken or loose.
(e) Malfunction Indicator Lamp
This lamp comes on when the ignition
key is turned to the “ON” position and
goes off after the engine starts. This
means that the warning light system is
operating properly.
If the lamp remains on, or the lamp
comes on while driving, first check the
followings.
Empty fuel tank
If the fuel tank is empty, refuel immedi-
ately.
Loose fuel tank cap
If the fuel tank cap is loose, securely
tighten it.
These cases are temporary malfunctions.
The malfunction indicator lamp will go off
after taking several driving trips.
If the lamp will not go off even after the
several trips, contact your Toyota dealer
as soon as possible.
If the fuel tank is not empty or the fuel
tank cap is not loose...
There is a problem somewhere in the
engine, emission control system, auto-
matic transmission electrical system or
warning light system itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.
Emissions Inspection and Maintenance
(I/M) programs
Your vehicle may not pass a state
emission inspection if the malfunction
indicator lamp remains on. Contact your
Toyota dealer to check your vehicle’s
emission control system and OBD
(OnBoard Diagnostics) system before
taking your vehicle for the inspection.
For details, see “Emissions Inspection and
Maintenance (I/M) programs” on page 200
in Section 6.

’03 Corolla U (L/O 0201)
2002003 MY COROLLA_U (OM12744U)
Some states have vehicle emission in-
spection programs which include OBD
(OnBoard Diagnostics) checks.
The OBD system monitors the operation
of the emission control system. When the
OBD system determines that a problem
exists somewhere in the emission control
system, the malfunction indicator lamp
comes on. In this case, your vehicle may
not pass the I/M test and need to be
repaired. Contact your Toyota dealer to
service the vehicle.
Even if the malfunction indicator lamp
does not come on, your vehicle may not
pass the I/M test as readiness codes
have not been set in the OBD system.
Readiness codes are automatically set
during ordinary driving. However, when the
battery is disconnected or run down, the
codes are erased. Also, depending on
your driving habits, the codes may not be
completely set. Also, if the malfunction indicator lamp had
come on recently due to temporary mal-
function such as a loose fuel tank cap,
your vehicle may not pass the I/M test.
The malfunction indicator lamp will go off
after taking several driving trips, but the
error code in the OBD system will not be
cleared unless about 40 trips or more are
taken.
If your vehicle does not pass the I/M test
even the malfunction indicator lamp does
not come on, contact your Toyota dealer
to prepare the vehicle for retesting.
Emissions Inspection and
Maintenance (I/M) programs

’03 Corolla U (L/O 0201)
2003 MY COROLLA_U (OM12744U)
Where to obtain the Repair Manual
The repair manual for COROLLA, written in
English, may be purchased as applicable from
any Toyota dealer.
Pub. Name: 2003 COROLLA Repair Manual
Pub. No.: RM938U1 (Maintenance, Preparation, Service specifications and Diagnostics)
RM938U2 (Engine, Chassis and
Body)
Maintenance procedures for the engine,
chassis, body, electrical system, and more,
are clearly explained and illustrated.
Periodic maintenance and tuneup
Periodic maintenance and tuneup helps to pre-
vent small problems from growing into larger ones lat-
er on. The repair manual outlines exactly what main-
tenance is required and clearly explains how to do the
work yourself stepbystep.
Areas covered include such things as spark plug re-
placement, valve clearance adjustment and engine oil
and filter replacement.